Losartan + Hydrochlorthiazide

Pharmacologic Category

Angiotensin II Receptor Blocker; Antihypertensive; Diuretic, Thiazide

Dosing: Adult

Hypertension: Oral: Note: Dose must be individualized; combination product may be substituted for individual components in patients currently maintained on both agents separately or in patients not adequately controlled with monotherapy. Not indicated for initial therapy of hypertension, except in severe hypertension.

Replacement therapy: Losartan 50 mg/hydrochlorothiazide 12.5 mg or losartan 100 mg/hydrochlorothiazide 12.5 mg or losartan 100 mg/hydrochlorothiazide 25 mg once daily; adjust dose base on blood pressure response. Maximum dose: Losartan 100 mg/hydrochlorothiazide 25 mg per day.

Severe hypertension: Initial: Losartan 50 mg/hydrochlorothiazide 12.5 mg once daily; may titrate dose after ~3 weeks. Maximum dose: Losartan 100 mg/hydrochlorothiazide 25 mg per day.

Hypertension with left ventricular hypertrophy: Oral: Note: Initiate treatment with losartan monotherapy. If blood pressure reduction inadequate, then may initiate losartan/hydrochlorothiazide combination.

Initial: Losartan 50 mg/hydrochlorothiazide 12.5 mg once daily; may increase to losartan 100 mg/hydrochlorothiazide 12.5 mg once daily, followed by losartan 100 mg/hydrochlorothiazide 25 mg once daily if needed to control blood pressure.

Dosing: Geriatric

Refer to adult dosing.

Dosing: Renal Impairment: Adult

CrCl > 30 mL/minute: No dosage adjustment necessary.

CrCl ≤30 mL/minute: Use is not recommended.

Dosing: Hepatic Impairment: Adult

Use is not recommended as initial therapy.

Calculations

Use: Labeled Indications

Hypertension: Management of hypertension.

Hypertension with left ventricular hypertrophy: To reduce the risk of stroke in patients with hypertension and left ventricular hypertrophy (LVH). Evidence suggests that this benefit does not apply to black patients.

Clinical Practice Guidelines

See individual agents.

Administration: Oral

Administer without regard to meals; however, administer consistently with respect to food intake at about the same time every day.

Dietary Considerations

Some products may contain potassium.

Storage/Stability

Store at 25°C (77°C); excursions are permitted between 15°C and 30°C (59°F and 86°F). Protect from light.

Medication Patient Education with HCAHPS Considerations

What is this drug used for?

• It is used to treat high blood pressure.

• It is used to prevent strokes.

• It may be given to you for other reasons. Talk with the doctor.

Frequently reported side effects of this drug

• Dizziness

• Common cold symptoms

• Back pain

• Runny nose

Other side effects of this drug: Talk with your doctor right away if you have any of these signs of:

• High blood sugar like confusion, fatigue, increased thirst, increased hunger, passing a lot of urine, flushing, fast breathing, or breath that smells like fruit.

• Kidney problems like unable to pass urine, blood in the urine, change in amount of urine passed, or weight gain.

• Fluid and electrolyte problems like mood changes, confusion, muscle pain or weakness, abnormal heartbeat, severe dizziness, passing out, fast heartbeat, increased thirst, seizures, loss of strength and energy, lack of appetite, unable to pass urine or change in amount of urine passed, dry mouth, dry eyes, nausea, or vomiting.

• Lupus like rash on the cheeks or other body parts, sunburn easy, muscle or joint pain, chest pain or shortness of breath, or swelling in the arms or legs.

• Swelling of arms or legs

• Skin changes

• Vision changes

• Eye pain

• Signs of a significant reaction like wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat.

Note: This is not a comprehensive list of all side effects. Talk to your doctor if you have questions.

Consumer Information Use and Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this medicine. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not specific medical advice and does not replace information you receive from the healthcare provider. You must talk with the healthcare provider for complete information about the risks and benefits of using this medicine.

Medication Safety Issues

Sound-alike/look-alike issues:

Geriatric Patients: High-Risk Medication:

Contraindications

Hypersensitivity to losartan, hydrochlorothiazide, sulfonamide-derived drugs, or any component of the formulation; concomitant use with aliskiren in patients with diabetes mellitus; anuria

Note: Although the product labeling states this medication is contraindicated with other sulfonamide-containing drug classes, the scientific basis of this statement has been challenged. See “Warnings/Precautions” for more detail.

Documentation of allergenic cross-reactivity for angiotensin receptor blockers or thiazide-type diuretics is limited. However, because of similarities in chemical structure and/or pharmacologic actions, the possibility of cross-sensitivity cannot be ruled out with certainty.

Canadian labeling: Additional contraindications (not in U.S. labeling): Concomitant use with aliskiren in patients with moderate-to-severe renal impairment (GFR <60 mL/minute/1.73 m²)

Warnings/Precautions

Concerns related to adverse effects:

• Angioedema: Angioedema has been reported rarely with some angiotensin II receptor antagonists (ARBs) and may occur at any time during treatment (especially following first dose). It may involve the head and neck (potentially compromising airway) or the intestine (presenting with abdominal pain). Patients with idiopathic or hereditary angioedema or previous angioedema associated with ACE-inhibitor therapy may be at an increased risk. Prolonged frequent monitoring may be required, especially if tongue, glottis, or larynx are involved, as they are associated with airway obstruction. Patients with a history of airway surgery may have a higher risk of airway obstruction. Discontinue therapy immediately if angioedema occurs. Aggressive early management is critical. Intramuscular (IM) administration of epinephrine may be necessary. Do not readminister to patients who have had angioedema with ARBs.

• Electrolyte disturbances: Hyperkalemia may occur with losartan; risk factors include renal dysfunction, diabetes mellitus, and concomitant use of potassium-sparing diuretics, potassium supplements, and/or potassium-containing salts. Use cautiously, if at all, with these agents and monitor potassium closely. Thiazide diuretics may cause hypokalemia, hypochloremic alkalosis, hypomagnesemia, and hyponatremia.

• Hypersensitivity reactions: Hypersensitivity reactions may occur with hydrochlorothiazide. Risk is increased in patients with a history of allergy or bronchial asthma.

• Hypotension: Symptomatic hypotension may occur upon initiation in patients who are salt- or volume-depleted (eg, those treated with high-dose diuretics); correct volume depletion prior to administration. This transient hypotensive response is not a contraindication to further treatment with losartan/hydrochlorothiazide.

• Ocular effects: Hydrochlorothiazide may cause acute transient myopia and acute angle-closure glaucoma, typically occurring within hours to weeks following initiation; discontinue therapy immediately in patients with acute decreases in visual acuity or ocular pain. Additional treatments may be needed if uncontrolled intraocular pressure persists. Risk factors may include a history of sulfonamide or penicillin allergy.

• Photosensitivity: Photosensitization may occur with use of hydrochlorothiazide.

• Renal function deterioration: May be associated with deterioration of renal function and/or increases in serum creatinine, particularly in patients with low renal blood flow (eg, renal artery stenosis, heart failure) whose glomerular filtration rate (GFR) is dependent on efferent arteriolar vasoconstriction by angiotensin II; deterioration may result in oliguria, acute renal failure, and progressive azotemia. Small increases in serum creatinine may occur following initiation; consider discontinuation only in patients with progressive and/or significant deterioration in renal function.

• Sulfonamide (“sulfa”) allergy: The product labeling for many medications containing a sulfonamide chemical group includes a broad contraindication in patients with a prior allergic reaction to sulfonamides. There is a potential for cross-reactivity between members of a specific class (eg, two antibiotic sulfonamides). However, concerns for cross-reactivity have previously extended to all compounds containing the sulfonamide structure (SO₂NH₂). An expanded understanding of allergic mechanisms indicates cross-reactivity between antibiotic sulfonamides and nonantibiotic sulfonamides may not occur or at the very least this potential is extremely low (Brackett 2004; Johnson 2005; Slatore 2004; Tornero 2004). In particular, mechanisms of cross-reaction due to antibody production (anaphylaxis) are unlikely to occur with nonantibiotic sulfonamides. T-cell-mediated (type IV) reactions (eg, maculopapular rash) are less well understood and it is not possible to completely exclude this potential based on current insights. In cases where prior reactions were severe (Stevens-Johnson syndrome/TEN), some clinicians choose to avoid exposure to these classes.

Disease-related concerns:

• Aortic/mitral stenosis: Use losartan with caution in patients with significant aortic/mitral stenosis.

• Bariatric surgery: Dehydration: Avoid diuretics in the immediate postoperative period after bariatric surgery; electrolyte disturbances and dehydration may occur. Diuretics may be resumed, if indicated, once oral fluid intake goals are met (Ziegler 2009).

• Diabetes: Use hydrochlorothiazide with caution in patients with prediabetes or diabetes mellitus; may see a change in glucose control.

• Gout: In certain patients with a history of gout, a familial predisposition to gout, or chronic renal failure, gout can be precipitated by hydrochlorothiazide. This risk may be increased with doses ≥25 mg (Gurwitz 1997).

• Hepatic impairment: Use is not recommended for initial therapy in patients with hepatic impairment. Use with caution in hepatic impairment or progressive hepatic disease; avoid electrolyte and acid/base imbalances that might lead to hepatic encephalopathy/coma.

• Hypercalcemia: Thiazide diuretics may decrease renal calcium excretion; consider avoiding use in patients with hypercalcemia.

• Hypercholesterolemia: Use with caution in patients with moderate or high cholesterol concentrations; increased cholesterol and triglyceride levels have been reported with thiazides.

• Parathyroid disease: Thiazide diuretics reduce calcium excretion; pathologic changes in the parathyroid glands with hypercalcemia and hypophosphatemia have been observed with prolonged use; should be discontinued prior to testing for parathyroid function.

• Renal artery stenosis: Use losartan with caution in patients with unstented unilateral/bilateral renal artery stenosis. When unstented bilateral renal artery stenosis is present, use is generally avoided due to the elevated risk of deterioration in renal function unless possible benefits outweigh risks.

• Renal impairment: Use losartan with caution with preexisting renal insufficiency. Avoid hydrochlorothiazide in severe renal disease (ineffective); may precipitate azotemia; discontinue or consider withholding if renal impairment occurs. Contraindicated in patients with anuria.

• Systemic lupus erythematosus (SLE): Hydrochlorothiazide can cause SLE exacerbation or activation.

Concurrent drug therapy issues:

• Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.

Special populations:

• Black patients: When used to reduce the risk of stroke in patients with HTN and LVH, may not be effective in the black population.

• Pregnancy: [US Boxed Warning]: Drugs that act on the renin-angiotensin system can cause injury and death to the developing fetus. Discontinue as soon as possible once pregnancy is detected.

• Surgical patients: In patients on chronic angiotensin receptor blocker (ARB) therapy, intraoperative hypotension may occur with induction and maintenance of general anesthesia; however, discontinuation of therapy prior to surgery is controversial. If continued preoperatively, avoidance of hypotensive agents during surgery is prudent (Hillis, 2011).

Other warnings/precautions:

• Appropriate use: Not indicated for initial therapy of hypertension, except in severe hypertension where the benefit of a prompt blood pressure reduction exceeds the risk of initiating combination therapy. Do not use as initial therapy in patients with intravascular volume depletion; correct prior to use.

Geriatric Considerations

See individual agents. Combination products are not recommended as first-line treatment. Use only if doses of individual agents correspond to the combination available. Hydrochlorothiazide is not effective in patients with a CrCl <30 mL/minute; therefore, it may not be a useful agent in many elderly patients.

Pregnancy Considerations

[US Boxed Warning]: Drugs that act directly on the renin-angiotensin system can cause injury and death to the developing fetus. When pregnancy is detected, discontinue therapy as soon as possible.

Refer to individual monographs for additional information.

Breast-Feeding Considerations

It is not known if losartan is excreted in breast milk; thiazide diuretics are excreted in breast milk.

Due to the potential for serious adverse reactions in the breastfed infant, the manufacturer recommends a decision be made whether to discontinue breastfeeding or to discontinue the drug, taking into account the importance of treatment to the mother.

Refer to individual monographs for additional information.

Briggs' Drugs in Pregnancy & Lactation

Adverse Reactions

Based on clinical trials of the combination product in patients with primary hypertension. Also see individual agents.

1% to 10%:

Nervous system: Dizziness (6%)

Neuromuscular & skeletal: Back pain (2%)

Respiratory: Upper respiratory tract infection (6%)

Frequency not defined:

Cardiovascular: Chest pain, hypersensitivity angiitis, necrotizing angiitis, orthostatic syncope (dose-related), palpitations, tachycardia, vasculitis

Dermatologic: Cutaneous lupus erythematosus, pruritus, skin photosensitivity, skin rash, toxic epidermal necrolysis, urticaria

Endocrine & metabolic: Electrolyte disorder, glycosuria, hyperglycemia, hyperuricemia, hypokalemia, hyponatremia

Gastrointestinal: Abdominal pain, anorexia, dysgeusia, dyspepsia, gastric irritation, nausea, pancreatitis, sialadenitis, vomiting

Genitourinary: Erectile dysfunction, impotence

Hematologic & oncologic: Agranulocytosis, anemia, aplastic anemia, hemolytic anemia, leukopenia, purpuric disease

Hepatic: Hepatic insufficiency, intrahepatic cholestatic jaundice, jaundice

Nervous system: Headache, insomnia, malaise, migraine, paresthesia, restlessness

Neuromuscular & skeletal: Arthralgia, asthenia, muscle cramps, muscle spasm, myalgia

Ophthalmic: Blurred vision (transient), xanthopsia

Renal: Interstitial nephritis, renal failure syndrome, renal insufficiency

Respiratory: Nasal congestion

Postmarketing: Anaphylaxis, erythroderma, rhabdomyolysis, thrombocytopenia

Allergy and Idiosyncratic Reactions

Toxicology

Angiotensin II Receptor Blockers

Metabolism/Transport Effects

Refer to individual components.

Drug Interactions Open Interactions

Ajmaline: Sulfonamides may enhance the adverse/toxic effect of Ajmaline. Specifically, the risk for cholestasis may be increased. Risk C: Monitor therapy

Alcohol (Ethyl): May enhance the orthostatic hypotensive effect of Thiazide and Thiazide-Like Diuretics. Risk C: Monitor therapy

Alfuzosin: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy

Aliskiren: May enhance the hyperkalemic effect of Angiotensin II Receptor Blockers. Aliskiren may enhance the hypotensive effect of Angiotensin II Receptor Blockers. Aliskiren may enhance the nephrotoxic effect of Angiotensin II Receptor Blockers. Management: Aliskiren use with ACEIs or ARBs in patients with diabetes is contraindicated. Combined use in other patients should be avoided, particularly when CrCl is less than 60 mL/min. If combined, monitor potassium, creatinine, and blood pressure closely. Risk D: Consider therapy modification

Allopurinol: Thiazide and Thiazide-Like Diuretics may enhance the potential for allergic or hypersensitivity reactions to Allopurinol. Thiazide and Thiazide-Like Diuretics may increase the serum concentration of Allopurinol. Specifically, Thiazide Diuretics may increase the concentration of Oxypurinol, an active metabolite of Allopurinol. Risk C: Monitor therapy

Alpelisib: May decrease the serum concentration of CYP2C9 Substrates (High risk with Inducers). Risk C: Monitor therapy

Amifostine: Blood Pressure Lowering Agents may enhance the hypotensive effect of Amifostine. Management: When amifostine is used at chemotherapy doses, blood pressure lowering medications should be withheld for 24 hours prior to amifostine administration. If blood pressure lowering therapy cannot be withheld, amifostine should not be administered. Risk D: Consider therapy modification

Aminolevulinic Acid (Systemic): Photosensitizing Agents may enhance the photosensitizing effect of Aminolevulinic Acid (Systemic). Risk X: Avoid combination

Aminolevulinic Acid (Topical): Photosensitizing Agents may enhance the photosensitizing effect of Aminolevulinic Acid (Topical). Risk C: Monitor therapy

Amphetamines: May diminish the antihypertensive effect of Antihypertensive Agents. Risk C: Monitor therapy

Angiotensin II: Receptor Blockers may diminish the therapeutic effect of Angiotensin II. Risk C: Monitor therapy

Angiotensin-Converting Enzyme Inhibitors: Angiotensin II Receptor Blockers may enhance the adverse/toxic effect of Angiotensin-Converting Enzyme Inhibitors. Angiotensin II Receptor Blockers may increase the serum concentration of Angiotensin-Converting Enzyme Inhibitors. Management: In US labeling, use of telmisartan and ramipril is not recommended. It is not clear if any other combination of an ACE inhibitor and an ARB would be any safer. Consider alternatives to the combination when possible. Risk D: Consider therapy modification

Anticholinergic Agents: May increase the serum concentration of Thiazide and Thiazide-Like Diuretics. Risk C: Monitor therapy

Antidiabetic Agents: Thiazide and Thiazide-Like Diuretics may diminish the therapeutic effect of Antidiabetic Agents. Risk C: Monitor therapy

Antidiabetic Agents: Hyperglycemia-Associated Agents may diminish the therapeutic effect of Antidiabetic Agents. Risk C: Monitor therapy

Antifungal Agents (Azole Derivatives, Systemic): May decrease the metabolism of Losartan. Applicable Isavuconazonium considerations are addressed in separate monographs. Exceptions: Isavuconazonium Sulfate. Risk C: Monitor therapy

Antihepaciviral Combination Products: May increase the serum concentration of Losartan. Management: Per antihepaciviral combination product US prescribing information, consider decreasing the losartan dose and monitoring for evidence of hypotension and worsening renal function if these agents are used in combination. Risk D: Consider therapy modification

Antipsychotic Agents (Second Generation [Atypical]): Blood Pressure Lowering Agents may enhance the hypotensive effect of Antipsychotic Agents (Second Generation [Atypical]). Risk C: Monitor therapy

Barbiturates: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy

Benperidol: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy

Beta2-Agonists: May enhance the hypokalemic effect of Thiazide and Thiazide-Like Diuretics. Risk C: Monitor therapy

Bile Acid Sequestrants: May decrease the absorption of Thiazide and Thiazide-Like Diuretics. The diuretic response is likewise decreased. Risk D: Consider therapy modification

Bosentan: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Risk C: Monitor therapy

Brigatinib: May diminish the antihypertensive effect of Antihypertensive Agents. Brigatinib may enhance the bradycardic effect of Antihypertensive Agents. Risk C: Monitor therapy

Brimonidine (Topical): May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy

Bromperidol: Blood Pressure Lowering Agents may enhance the hypotensive effect of Bromperidol. Bromperidol may diminish the hypotensive effect of Blood Pressure Lowering Agents. Risk X: Avoid combination

Calcium Salts: Thiazide and Thiazide-Like Diuretics may decrease the excretion of Calcium Salts. Continued concomitant use can also result in metabolic alkalosis. Risk C: Monitor therapy

Cardiac Glycosides: Thiazide and Thiazide-Like Diuretics may enhance the adverse/toxic effect of Cardiac Glycosides. Specifically, cardiac glycoside toxicity may be enhanced by the hypokalemic and hypomagnesemic effect of thiazide diuretics. Risk C: Monitor therapy

Corticosteroids (Orally Inhaled): May enhance the hypokalemic effect of Thiazide and Thiazide-Like Diuretics. Risk C: Monitor therapy

Corticosteroids (Systemic): May enhance the hypokalemic effect of Thiazide and Thiazide-Like Diuretics. Risk C: Monitor therapy

Cyclophosphamide: Thiazide and Thiazide-Like Diuretics may enhance the adverse/toxic effect of Cyclophosphamide. Specifically, granulocytopenia may be enhanced. Risk C: Monitor therapy

CycloSPORINE (Systemic): Angiotensin II Receptor Blockers may enhance the hyperkalemic effect of CycloSPORINE (Systemic). Risk C: Monitor therapy

CYP2C9 Inhibitors (Moderate): May decrease the metabolism of CYP2C9 Substrates (High risk with Inhibitors). Risk C: Monitor therapy

CYP3A4 Inducers (Moderate): May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Risk C: Monitor therapy

CYP3A4 Inducers (Strong): May increase the metabolism of CYP3A4 Substrates (High risk with Inducers). Management: Consider an alternative for one of the interacting drugs. Some combinations may be specifically contraindicated. Consult appropriate manufacturer labeling. Risk D: Consider therapy modification

Dabrafenib: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Management: Seek alternatives to the CYP3A4 substrate when possible. If concomitant therapy cannot be avoided, monitor clinical effects of the substrate closely (particularly therapeutic effects). Risk D: Consider therapy modification

Dabrafenib: May decrease the serum concentration of CYP2C9 Substrates (High risk with Inducers). Management: Seek alternatives to the CYP2C9 substrate when possible. If concomitant therapy cannot be avoided, monitor clinical effects of the substrate closely (particularly therapeutic effects). Risk D: Consider therapy modification

Dapoxetine: May enhance the orthostatic hypotensive effect of Angiotensin II Receptor Blockers. Risk C: Monitor therapy

Deferasirox: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Risk C: Monitor therapy

Dexketoprofen: May enhance the adverse/toxic effect of Sulfonamides. Risk C: Monitor therapy

Dexmethylphenidate: May diminish the therapeutic effect of Antihypertensive Agents. Risk C: Monitor therapy

Diacerein: May enhance the therapeutic effect of Diuretics. Specifically, the risk for dehydration or hypokalemia may be increased. Risk C: Monitor therapy

Diazoxide: Thiazide and Thiazide-Like Diuretics may enhance the adverse/toxic effect of Diazoxide. Risk C: Monitor therapy

Diazoxide: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy

Dichlorphenamide: Thiazide and Thiazide-Like Diuretics may enhance the hypokalemic effect of Dichlorphenamide. Risk C: Monitor therapy

Dofetilide: HydroCHLOROthiazide may enhance the QTc-prolonging effect of Dofetilide. HydroCHLOROthiazide may increase the serum concentration of Dofetilide. Risk X: Avoid combination

Drospirenone: Angiotensin II Receptor Blockers may enhance the hyperkalemic effect of Drospirenone. Risk C: Monitor therapy

DULoxetine: Blood Pressure Lowering Agents may enhance the hypotensive effect of DULoxetine. Risk C: Monitor therapy

Enzalutamide: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Management: Concurrent use of enzalutamide with CYP3A4 substrates that have a narrow therapeutic index should be avoided. Use of enzalutamide and any other CYP3A4 substrate should be performed with caution and close monitoring. Risk D: Consider therapy modification

Enzalutamide: May decrease the serum concentration of CYP2C9 Substrates (High risk with Inducers). Management: Concurrent use of enzalutamide with CYP2C9 substrates that have a narrow therapeutic index should be avoided. Use of enzalutamide and any other CYP2C9 substrate should be performed with caution and close monitoring. Risk D: Consider therapy modification

Eplerenone: May enhance the hyperkalemic effect of Angiotensin II Receptor Blockers. Risk C: Monitor therapy

Erdafitinib: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Risk C: Monitor therapy

Fexinidazole [INT]: Thiazide and Thiazide-Like Diuretics may enhance the arrhythmogenic effect of Fexinidazole [INT]. Risk X: Avoid combination

Fluconazole: May decrease the serum concentration of Losartan. Specifically, fluconazole may decrease the serum concentration of E3174, the more potent active metabolite of losartan. Risk C: Monitor therapy

Heparin: May enhance the hyperkalemic effect of Angiotensin II Receptor Blockers. Risk C: Monitor therapy

Heparins (Low Molecular Weight): May enhance the hyperkalemic effect of Angiotensin II Receptor Blockers. Risk C: Monitor therapy

Herbs (Hypertensive Properties): May diminish the antihypertensive effect of Antihypertensive Agents. Risk C: Monitor therapy

Herbs (Hypotensive Properties): May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy

Hypotension-Associated Agents: Blood Pressure Lowering Agents may enhance the hypotensive effect of Hypotension-Associated Agents. Risk C: Monitor therapy

Ipragliflozin: May enhance the adverse/toxic effect of Thiazide and Thiazide-Like Diuretics. Specifically, the risk for intravascular volume depletion may be increased. Risk C: Monitor therapy

Ivabradine: Thiazide and Thiazide-Like Diuretics may enhance the arrhythmogenic effect of Ivabradine. Risk C: Monitor therapy

Ivosidenib: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Risk C: Monitor therapy

Levodopa-Containing Products: Blood Pressure Lowering Agents may enhance the hypotensive effect of Levodopa-Containing Products. Risk C: Monitor therapy

Levosulpiride: Thiazide and Thiazide-Like Diuretics may enhance the adverse/toxic effect of Levosulpiride. Risk X: Avoid combination

Licorice: May enhance the hypokalemic effect of Thiazide and Thiazide-Like Diuretics. Risk C: Monitor therapy

Lithium: Thiazide and Thiazide-Like Diuretics may decrease the excretion of Lithium. Risk D: Consider therapy modification

Lithium: Angiotensin II Receptor Blockers may increase the serum concentration of Lithium. Management: Lithium dosage reductions will likely be needed following the addition of an angiotensin II receptor antagonist. Risk D: Consider therapy modification

Lormetazepam: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy

Mecamylamine: Sulfonamides may enhance the adverse/toxic effect of Mecamylamine. Risk X: Avoid combination

Methenamine: Thiazide and Thiazide-Like Diuretics may diminish the therapeutic effect of Methenamine. Risk C: Monitor therapy

Methylphenidate: May diminish the antihypertensive effect of Antihypertensive Agents. Risk C: Monitor therapy

MiFEPRIStone: May increase the serum concentration of CYP2C9 Substrates (High risk with Inhibitors). Management: Use CYP2C9 substrates at the lowest recommended dose, and monitor closely for adverse effects, during and in the 2 weeks following mifepristone treatment. Risk D: Consider therapy modification

Mitotane: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Management: Doses of CYP3A4 substrates may need to be adjusted substantially when used in patients being treated with mitotane. Risk D: Consider therapy modification

Molsidomine: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy

Multivitamins/Fluoride (with ADE): May enhance the hypercalcemic effect of Thiazide and Thiazide-Like Diuretics. Risk C: Monitor therapy

Multivitamins/Minerals (with ADEK, Folate, Iron): Thiazide and Thiazide-Like Diuretics may enhance the hypercalcemic effect of Multivitamins/Minerals (with ADEK, Folate, Iron). Risk C: Monitor therapy

Multivitamins/Minerals (with AE, No Iron): Thiazide and Thiazide-Like Diuretics may increase the serum concentration of Multivitamins/Minerals (with AE, No Iron). Specifically, thiazide diuretics may decrease the excretion of calcium, and continued concomitant use can also result in metabolic alkalosis. Risk C: Monitor therapy

Naftopidil: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy

Neuromuscular-Blocking Agents (Nondepolarizing): Thiazide and Thiazide-Like Diuretics may enhance the neuromuscular-blocking effect of Neuromuscular-Blocking Agents (Nondepolarizing). Risk C: Monitor therapy

Nicergoline: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy

Nicorandil: May enhance the hyperkalemic effect of Angiotensin II Receptor Blockers. Risk C: Monitor therapy

Nicorandil: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy

Nitroprusside: Blood Pressure Lowering Agents may enhance the hypotensive effect of Nitroprusside. Risk C: Monitor therapy

Nonsteroidal Anti-Inflammatory Agents: Thiazide and Thiazide-Like Diuretics may enhance the nephrotoxic effect of Nonsteroidal Anti-Inflammatory Agents. Nonsteroidal Anti-Inflammatory Agents may diminish the therapeutic effect of Thiazide and Thiazide-Like Diuretics. Risk C: Monitor therapy

Nonsteroidal Anti-Inflammatory Agents: Angiotensin II Receptor Blockers may enhance the adverse/toxic effect of Nonsteroidal Anti-Inflammatory Agents. Specifically, the combination may result in a significant decrease in renal function. Nonsteroidal Anti-Inflammatory Agents may diminish the therapeutic effect of Angiotensin II Receptor Blockers. The combination of these two agents may also significantly decrease glomerular filtration and renal function. Risk C: Monitor therapy

Obinutuzumab: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Management: Consider temporarily withholding blood pressure lowering medications beginning 12 hours prior to obinutuzumab infusion and continuing until 1 hour after the end of the infusion. Risk D: Consider therapy modification

Opioid Agonists: May enhance the adverse/toxic effect of Diuretics. Opioid Agonists may diminish the therapeutic effect of Diuretics. Risk C: Monitor therapy

OXcarbazepine: Thiazide and Thiazide-Like Diuretics may enhance the adverse/toxic effect of OXcarbazepine. Specifically, there may be an increased risk for hyponatremia. Risk C: Monitor therapy

Pentoxifylline: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy

Pholcodine: Blood Pressure Lowering Agents may enhance the hypotensive effect of Pholcodine. Risk C: Monitor therapy

Phosphodiesterase 5 Inhibitors: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy

Porfimer: Photosensitizing Agents may enhance the photosensitizing effect of Porfimer. Risk C: Monitor therapy

Potassium Salts: May enhance the hyperkalemic effect of Angiotensin II Receptor Blockers. Risk C: Monitor therapy

Potassium-Sparing Diuretics: Angiotensin II Receptor Blockers may enhance the hyperkalemic effect of Potassium-Sparing Diuretics. Risk C: Monitor therapy

Promazine: Thiazide and Thiazide-Like Diuretics may enhance the QTc-prolonging effect of Promazine. Risk X: Avoid combination

Prostacyclin Analogues: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy

Quinagolide: May enhance the hypotensive effect of Blood Pressure Lowering Agents. Risk C: Monitor therapy

Ranolazine: May enhance the adverse/toxic effect of Angiotensin II Receptor Blockers. Risk C: Monitor therapy

Reboxetine: May enhance the hypokalemic effect of Thiazide and Thiazide-Like Diuretics. Risk C: Monitor therapy

Resveratrol: May decrease serum concentrations of the active metabolite(s) of Losartan. Resveratrol may increase the serum concentration of Losartan. Risk C: Monitor therapy

RifAMPin: May decrease the serum concentration of Losartan. Risk C: Monitor therapy

Rifapentine: May decrease the serum concentration of CYP2C9 Substrates (High risk with Inducers). Risk C: Monitor therapy

Sarilumab: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Risk C: Monitor therapy

Selective Serotonin Reuptake Inhibitors: May enhance the hyponatremic effect of Thiazide and Thiazide-Like Diuretics. Risk C: Monitor therapy

Siltuximab: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Risk C: Monitor therapy

Sodium Phosphates: Angiotensin II Receptor Blockers may enhance the nephrotoxic effect of Sodium Phosphates. Specifically, the risk of acute phosphate nephropathy may be enhanced. Management: Consider avoiding this combination by temporarily suspending treatment with ARBs, or seeking alternatives to oral sodium phosphate bowel preparation. If the combination cannot be avoided, maintain adequate hydration and monitor renal function closely. Risk D: Consider therapy modification

Sodium Phosphates: Diuretics may enhance the nephrotoxic effect of Sodium Phosphates. Specifically, the risk of acute phosphate nephropathy may be enhanced. Management: Consider avoiding this combination by temporarily suspending treatment with diuretics, or seeking alternatives to oral sodium phosphate bowel preparation. If the combination cannot be avoided, hydrate adequately and monitor fluid and renal status. Risk D: Consider therapy modification

Tacrolimus (Systemic): Angiotensin II Receptor Blockers may enhance the hyperkalemic effect of Tacrolimus (Systemic). Risk C: Monitor therapy

Tocilizumab: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Risk C: Monitor therapy

Tolvaptan: May enhance the hyperkalemic effect of Angiotensin II Receptor Blockers. Risk C: Monitor therapy

Topiramate: Thiazide and Thiazide-Like Diuretics may enhance the hypokalemic effect of Topiramate. Thiazide and Thiazide-Like Diuretics may increase the serum concentration of Topiramate. Management: Monitor for increased topiramate levels/adverse effects (e.g., hypokalemia) with initiation/dose increase of a thiazide diuretic. Closely monitor serum potassium concentrations with concomitant therapy. Topiramate dose reductions may be necessary. Risk D: Consider therapy modification

Toremifene: Thiazide and Thiazide-Like Diuretics may enhance the hypercalcemic effect of Toremifene. Risk C: Monitor therapy

Trimethoprim: May enhance the hyperkalemic effect of Angiotensin II Receptor Blockers. Risk C: Monitor therapy

Valsartan: HydroCHLOROthiazide may enhance the hypotensive effect of Valsartan. Valsartan may increase the serum concentration of HydroCHLOROthiazide. Risk C: Monitor therapy

Verteporfin: Photosensitizing Agents may enhance the photosensitizing effect of Verteporfin. Risk C: Monitor therapy

Vitamin D Analogs: Thiazide and Thiazide-Like Diuretics may enhance the hypercalcemic effect of Vitamin D Analogs. Risk C: Monitor therapy

Yohimbine: May diminish the antihypertensive effect of Antihypertensive Agents. Risk C: Monitor therapy

Test Interactions

See individual agents.

Genes of Interest

Monitoring Parameters

Baseline and periodic blood pressure, serum electrolytes, renal function

Advanced Practitioners Physical Assessment/Monitoring

See individual agents.

Nursing Physical Assessment/Monitoring

See individual agents.

Dosage Forms: US

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Tablet, Oral:

Hyzaar 50/12.5: Losartan potassium 50 mg and hydrochlorothiazide 12.5 mg [contains potassium 4.24 mg (0.108 mEq)]

Hyzaar 100/12.5: Losartan potassium 100 mg and hydrochlorothiazide 12.5 mg [contains potassium 8.48 mg (0.216 mEq)]

Hyzaar 100/25: Losartan potassium 100 mg and hydrochlorothiazide 25 mg [contains potassium 8.48 mg (0.216 mEq)]

Generic: 50/12.5: Losartan potassium 50 mg and hydrochlorothiazide 12.5 mg; 100/12.5: Losartan potassium 100 mg and hydrochlorothiazide 12.5 mg; 100/25: Losartan potassium 100 mg and hydrochlorothiazide 25 mg

Anatomic Therapeutic Chemical (ATC) Classification

C09DA01

Generic Available (US)

Yes

Pricing: US

Tablets (Hyzaar Oral)

50-12.5 mg (per each): $4.92

100-12.5 mg (per each): $6.72

100-25 mg (per each): $6.72

Tablets (Losartan Potassium-HCTZ Oral)

50-12.5 mg (per each): $0.04 - $2.50

100-12.5 mg (per each): $0.05 - $3.41

100-25 mg (per each): $0.06 - $3.41

Disclaimer: A representative AWP (Average Wholesale Price) price or price range is provided as reference price only. A range is provided when more than one manufacturer's AWP price is available and uses the low and high price reported by the manufacturers to determine the range. The pricing data should be used for benchmarking purposes only, and as such should not be used alone to set or adjudicate any prices for reimbursement or purchasing functions or considered to be an exact price for a single product and/or manufacturer. Medi-Span expressly disclaims all warranties of any kind or nature, whether express or implied, and assumes no liability with respect to accuracy of price or price range data published in its solutions. In no event shall Medi-Span be liable for special, indirect, incidental, or consequential damages arising from use of price or price range data. Pricing data is updated monthly.

Mechanism of Action

Losartan: As a selective and competitive, nonpeptide angiotensin II receptor antagonist, losartan blocks the vasoconstrictor and aldosterone-secreting effects of angiotensin II; losartan interacts reversibly at the AT1 and AT2 receptors of many tissues and has slow dissociation kinetics; its affinity for the AT1 receptor is 1000 times greater than the AT2 receptor. Angiotensin II receptor antagonists may induce a more complete inhibition of the renin-angiotensin system than ACE inhibitors, they do not affect the response to bradykinin, and are less likely to be associated with nonrenin-angiotensin effects (eg, cough and angioedema). Losartan increases urinary flow rate and in addition to being natriuretic and kaliuretic, increases excretion of chloride, magnesium, uric acid, calcium, and phosphate.

Hydrochlorothiazide: Inhibits sodium reabsorption in the distal tubules causing increased excretion of sodium and water as well as potassium and hydrogen ions.

Pharmacodynamics/Kinetics

See individual agents.

Local Anesthetic/Vasoconstrictor Precautions

No information available to require special precautions

Effects on Dental Treatment

Key adverse event(s) related to dental treatment: Patients may experience orthostatic hypotension as they stand up after treatment; especially if lying in dental chair for extended periods of time. Use caution with sudden changes in position during and after dental treatment.

Effects on Bleeding

No information available to require special precautions

Related Information

Index Terms

Hydrochlorothiazide and Losartan; Losartan/Hydrochlorothiazide

References

2019 American Geriatrics Society Beers Criteria Update Expert Panel. American Geriatrics Society 2019 Updated AGS Beers Criteria for Potentially Inappropriate Medication Use in Older Adults. J Am Geriatr Soc. 2019;67(4):674-694. doi: 10.1111/jgs.15767.[PubMed 30693946]

Brackett CC, Singh H, Block JH. Likelihood and mechanisms of cross-allergenicity between sulfonamide antibiotics and other drugs containing a sulfonamide functional group. Pharmacotherapy. 2004;24(7):856-870.[PubMed 15303450]

Cohn JN and Tognoni G, “Valsartan Heart Failure Trial Investigators. A Randomized Trial of the Angiotensin-Receptor Blocker Valsartan in Chronic Heart Failure,” N Engl J Med, 2001, 345(23):1667-75.[PubMed 11759645]

Dahlof B, Devereux RB, Kjeldsen SE, et al, “Cardiovascular Morbidity and Mortality in the Losartan Intervention For Endpoint Reduction in Hypertension Study (LIFE): A Randomised Trial Against Atenolol,” Lancet, 2002, 359(9311):995-1003.[PubMed 11937178]

Dickstein K, Kjekshus J, et al, "Effects of Losartan and Captopril on Mortality and Morbidity in High-Risk Patients After Acute Myocardial Infarction: The OPTIMAAL Randomised Trial. Optimal Trial in Myocardial Infarction with Angiotensin II Antagonist Losartan," Lancet, 2002, 360(9335):752-60.[PubMed 12241832]

Epstein BJ and Gums JG, "Angiotensin Receptor Blockers Versus ACE Inhibitors: Prevention of Death and Myocardial Infarction in High-Risk Populations," Ann Pharmacother, 2005, 39(3):470-80.[PubMed 15701766]

Granger CB, McMurray JJ, Yusuf S, et al, "Effects of Candesartan in Patients With Chronic Heart Failure and Reduced Left-Ventricular Systolic Function Intolerant to Angiotensin-Converting-Enzyme Inhibitors: The CHARM-Alternative Trial," Lancet, 2003, 362(9386):772-6.[PubMed 13678870]

Gurwitz JH, Kalish SC, Bohn RL, et al. Thiazide diuretics and the initiation of anti-gout therapy. J Clin Epidemiol. 1997;50(8):953-959.[PubMed 9291881 ]

Hillis LD, Smith PK, Anderson JL, et al. 2011 ACCF/AHA Guideline for Coronary Artery Bypass Graft Surgery: A Report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines. Circulation. 2011, 124(23):2610-42.[PubMed 22064600]

Hyzaar (losartan/hydrochlorothiazide) [prescribing information]. Whitehouse Station, NJ: Merck & Co; November 2019.

Hyzaar and Hyzaar DS (losartan/hydrochlorothiazide) [product monograph]. Kirkland, Quebec, Canada: Merck Canada Inc; June 2019.

Johnson KK, Green DL, Rife JP, Limon L. Sulfonamide cross-reactivity: fact or fiction? [published correction appears in Ann Pharmacother. 2005;39(7-8):1373]. Ann Pharmacother. 2005;39(2):290-301.[PubMed 15644481]

Kaplan NM and Sever PS, “Combination Therapy: A Key to Comprehensive Patient Care,” Am J Hypertens, 1997, 10(7 Pt 2):127S.[PubMed 9231887]

McMurray JJ, Ostergren J, Swedberg K, et al, "Effects of Candesartan in Patients With Chronic Heart Failure and Reduced Left-Ventricular Systolic Function Taking Angiotensin-Converting-Enzyme Inhibitors: The CHARM-Added Trial," Lancet, 2003, 362(9386):767-71.[PubMed 13678869]

Moser M and Black HR, “The Role of Combination Therapy in the Treatment of Hypertension,” Am J Hypertens, 1998, 11(6 Pt 2):73S-8S, 95S-100S.[PubMed 9655566]

Pfeffer MA, McMurray JJ, Velazquez EJ, et al, "Valsartan, Captopril, or Both in Myocardial Infarction Complicated by Heart Failure, Left Ventricular Dysfunction, or Both," N Engl J Med, 2004, 350(2):203.

Pitt B, Poole-Wilson PA, Segal R, et al, "Effect of Losartan Compared With Captopril on Mortality in Patients With Symptomatic Heart Failure: Randomised Trial - The Losartan Heart Failure Survival Study ELITE II," Lancet, 2000, 355(9215):1582-7.[PubMed 10821361]

Sipahi I, Debanne SM, Rowland DY, et al, “Angiotensin-Receptor Blockade and Risk of Cancer: Meta-Analysis of Randomised Controlled Trials,” Lancet Oncol, 2010, 11(7):627-36.[PubMed 20542468]

Slatore CG, Tilles SA. Sulfonamide hypersensitivity. Immunol Allergy Clin North Am. 2004;24(3):477-490.[PubMed 15242722]

Tornero P, De Barrio M, Baeza ML, Herrero T. Cross-reactivity among p-amino group compounds in sulfonamide fixed drug eruption: diagnostic value of patch testing. Contact Dermatitis. 2004;51(2):57-62.[PubMed 15373844]

Ziegler O, Sirveaux MA, Brunaud L, Reibel N, Quilliot D. Medical follow up after bariatric surgery: nutritional and drug issues. General recommendations for the prevention and treatment of nutritional deficiencies. Diabetes Metab. 2009;35(6, pt 2):544-557. doi: 10.1016/S1262-3636(09)73464-0.[PubMed 20152742]

Brand Names: International

2Zaris (PH); Acetan HCT (MY); Agilosart-H (VN); Angioretic (EC); Anzaplus (PH); Artazide (PH); Atostar-H (LK); Cadrzaar (LB); Cardiovasc (EC); Co-Normoten (PH); Combetzar (PH); Convertal D (UY); Corodin-D (CL, PY); Corus-H (BR); Cosaar Plus (AT, CH); Cosartal,Plus (IE); Cosca Plus (KR); Cosca Plus-F (KR); Cozaar Comp (IS, MT); Cozaar Plus (DK, ES, KR, PT); Cozaar Plus F (KR); Cozaar Plus Pro (KR); Cozaar-Comp (FI, GB, IE, NO); Cozaarex D (AR); Cozatan Comp (IE); Ecozar Plus (PH); Fortzaar (AE, CY, FR, HR, IT, KW, MY, PT, QA, RO, SA, SE, TH); Hisart (TW); Hysartan (EG); Hyzaar (AE, BB, BM, BS, BZ, CL, CR, CY, CZ, DO, EC, EG, FR, GR, GT, GY, HK, HN, HR, ID, JM, JO, KW, LB, LK, MX, MY, NI, NL, NZ, PA, PE, PH, PK, PL, QA, RO, SA, SG, SI, SK, SR, SV, TH, TR, TT, TW, VE, VN); Hyzaar DS (PH); Hyzaar Forte (HK, SG, TW); Hyzaar Plus (HK, SG); Kenzar Plus (PH); Ko-Sentor (UA); Loraz Forte (EG); Lorista H (LV); Lorzaar Plus (DE); Losacar-H (PH); Losacor D (AR, PE); Losacor HCT (HK); Losanet (QA); Losardex PLus (IL); Losargard Plus (PH); Losarlife-H (VN); Losart Plus (BD); Losartan Plus (IL); Lostad HCT (HK, MY); Lotan Plus (IL); Lozap H (BG, EE, LV); Lozarsin (KR); Lozetin Plus (KR); Lozo-H (LK); Ocsaar Plus (IL); Osartan Plus (KR); Preminent (JP); Preminent HD (JP); Presartan H50 (ZW); Prozart Plus (PH); Rosa Plus F (KR); Rosatan H (BD); Roza Plus (KR); Rozataplus (KR); Sarlotan Plus (KR); Sartens Plus (LV); Satoren H (CO); Sortiva-H (BH); Synzar (TW); Tensarten-HCT (CO); Tozaar-H (TZ); Troysar-H (VN); Vivasartan Plus (PH); Wilopres Plus (PH); Zaart-H (IN); Zosaar HCT (MY); Zylovaa-H (MY)

Last Updated 2/20/20

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