Embedded Files
Pharmacologic Category
Dosing: Adult
Benign prostatic hyperplasia (BPH): Males: Oral: 0.5 mg once daily alone or in combination with tamsulosin
* See Dosage and Administration in AHFS Essentials for additional information.
Dosing: Geriatric
Refer to adult dosing.
Dosing: Renal Impairment: Adult
No dosage adjustment is necessary
Dosing: Hepatic Impairment: Adult
There are no dosage adjustments provided in the manufacturer’s labeling (has not been studied). Dutasteride is extensively hepatically metabolized and exposure could be increased in hepatic impairment, however, higher doses studied did not generally produce additional adverse effects.
Use: Labeled Indications
Benign prostatic hyperplasia: Treatment of symptomatic benign prostatic hyperplasia (BPH) as monotherapy (to improve symptoms, reduce the risk of acute urinary retention, and to reduce the risk of need for BPH-related surgery) or combination therapy with tamsulosin
Limitations of use: Not approved for the prevention of prostate cancer.
* See Uses in AHFS Essentials for additional information.
Use: Off-Label: Adult
Male pattern baldnessLevel of Evidence [B]
Two randomized, placebo-controlled trials demonstrated efficacy of dutasteride in increased hair growth compared to placebo, with the most common side effect reported was decreased libido or sexual dysfunction Ref. In one of the trials, dutasteride 2.5 mg demonstrated superiority to finasteride 5 mg at 12 and 24 weeks; however, androgen-related adverse effects may also occur more frequently with dutasteride due to its potency Ref. Additional trials may be necessary to further define the role of dutasteride in the treatment of this condition.
Level of Evidence Definitions
Level of Evidence Scale
Use: Unsupported: Adult
Prostate cancer prevention
The effects of dutasteride on prevention of prostate cancer were evaluated in a large, multicenter, randomized, placebo-controlled study in men considered at increased risk for prostate cancer, which found a statistically significant increase in the incidence of higher grade prostate cancer (Gleason score 8 to 10) at 4 years in men who received dutasteride (Andriole 2010).
Class and Related Monographs
Clinical Practice Guidelines
Benign Prostatic Hyperplasia:
CUA, “Guideline on Male Lower Urinary Tract Symptoms/Benign Prostatic Hyperplasia (MLUTS/BPH),” 2018
Administration: Oral
May be administered without regard to meals. Capsule should be swallowed whole; do not chew or open; contact with opened capsule can cause oropharyngeal irritation. Should not be touched or handled by women who are pregnant or may be pregnant.
Hazardous Drugs Handling Considerations
Hazardous agent (NIOSH 2016 [group 3]).
Use appropriate precautions for receiving, handling, administration, and disposal. Gloves (single) should be worn during receiving, unpacking, and placing in storage. NIOSH recommends single gloving for administration of intact tablets or capsules (NIOSH 2016). Assess risk to determine appropriate containment strategy (USP-NF 2017).
Storage/Stability
Store at controlled room temperature of 25°C (77°F); excursions permitted to 15°C to 30°C (59°F to 86°F).
Medication Patient Education with HCAHPS Considerations
What is this drug used for?
• In men, it is used to treat the signs of an enlarged prostate.
• It may be given to you for other reasons. Talk with the doctor.
All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:
• Dizziness
• Sexual dysfunction
• Decreased sex drive
WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:
• Lump in breast
• Breast pain or soreness
• Nipple discharge
• Enlarged breasts
• Depression
• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, 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 limited summary of general information about the medicine's uses from the patient education leaflet and is not intended to be comprehensive. This limited summary does NOT include all information available about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not intended to provide medical advice, diagnosis or treatment and does not replace information you receive from the healthcare provider. For a more detailed summary of information about the risks and benefits of using this medicine, please speak with your healthcare provider and review the entire patient education leaflet.
Contraindications
Clinically significant hypersensitivity to dutasteride, other 5-alpha-reductase inhibitors (eg, finasteride), or any component of the formulation; pregnancy.
Warnings/Precautions
Disease-related concerns:
• Diminished urinary flow: Carefully monitor patients with a large residual urinary volume or severely diminished urinary flow for obstructive uropathy; these patients may not be candidates for dutasteride therapy.
• Hepatic impairment: Use with caution in patients with hepatic impairment.
• Prostate cancer: When compared to placebo, 5-alpha-reductase inhibitors (5-ARIs) have been shown to reduce the overall incidence of prostate cancer, although an increase in the incidence of high-grade prostate cancers has been observed; 5-ARIs are not approved in the United States or Canada for the prevention of prostate cancer.
Concurrent drug therapy issues:
• CYP3A4 inhibitors: Use with caution with concurrent use of potent, chronic CYP3A4 inhibitors.
Other warnings/precautions:
• Appropriate use: Other urological diseases, including prostate cancer, should be ruled out before initiating therapy.
• Blood donation: Avoid donating blood during or for 6 months following treatment cessation due to risk of administration to a pregnant female transfusion recipient.
• PSA monitoring: Reduces prostate specific antigen (PSA) by ~50% within 3-6 months of use. If following serial PSAs, re-establish a new baseline ≥3 months after treatment initiation; monitor PSA periodically thereafter. If interpreting an isolated PSA value in a patient treated for ≥3 months, then double the PSA value for comparison to a normal PSA value in an untreated man. PSA increases while on dutasteride should be considered suspicious; obtain serial PSA measurements and evaluate (Andriole, 2006). Patients on a 5-ARI with any increase in PSA levels, even if within normal limits, should be evaluated; may indicate presence of prostate cancer.
* See Cautions in AHFS Essentials for additional information.
Geriatric Considerations
No dosage adjustment necessary.
Reproductive Considerations
Dutasteride can be detected in semen; sperm count, semen volume, and sperm movement may be decreased, but the effect on male fertility is unknown.
Pregnancy Considerations
Based on the mechanism of action and data from animal reproduction studies, in utero exposure to dutasteride may cause fetal harm. Use is contraindicated in pregnant women.
Capsules should not be handled by pregnant women or women who may be pregnant; if contact with a leaking capsule occurs, wash area immediately with soap and water.
Breast-Feeding Considerations
It is not known if dutasteride is present in breast milk.
Adverse Reactions
Frequency of most adverse events (except prostate cancer high grade) tends to decrease with continued use (>6 months). Frequency not always defined.
1% to 10%:
Endocrine & metabolic: Decreased libido (≤3%; incidence highest during first 6 months of therapy), gynecomastia (including breast tenderness, breast enlargement; ≤1%), increased luteinizing hormone, increased testosterone level, increased thyroid stimulating hormone level
Genitourinary: Impotence (≤5%; incidence highest during first 6 months of therapy), ejaculatory disorder (≤2%)
Hematologic & oncologic: Prostate cancer high grade (≤1%)
<1%, postmarketing, and/or case reports: Angioedema, cardiac failure, depressed mood, dermatological reaction (serious), dizziness, hypersensitivity, localized edema, malignant neoplasm of breast (males), pruritus, skin rash, testicular pain, testicular swelling, urticaria
* See Cautions in AHFS Essentials for additional information.
Allergy and Idiosyncratic Reactions
Metabolism/Transport Effects
Substrate of CYP3A4 (minor); Note: Assignment of Major/Minor substrate status based on clinically relevant drug interaction potential
Drug Interactions Open Interactions
CYP3A4 Inhibitors (Strong): May increase the serum concentration of Dutasteride. Risk C: Monitor therapy
Food Interactions
Maximum serum concentrations reduced by 10% to 15% when taken with food; not clinically significant. Management: Administer without regard to meals.
Test Interactions
PSA levels decrease in treated patients. After 3 months of therapy, PSA levels stabilize to a new baseline that is ~50% of pretreatment values. If following serial PSAs in a patient, re-establish a new baseline after ≥3 months of use. If interpreting an isolated PSA value in a patient treated for ≥3 months, then double the PSA value for comparison.
Monitoring Parameters
Objective and subjective signs of relief of benign prostatic hyperplasia, including improvement in urinary flow, reduction in symptoms of urgency, and relief of difficulty in micturition; for serial PSA monitoring, establish a new baseline PSA level after 3 months of therapy and monitor PSA periodically thereafter.
Advanced Practitioners Physical Assessment/Monitoring
Obtain a new baseline PSA after 3 months of therapy and then monitor PSA periodically thereafter. Assess for effectiveness of therapy.
Nursing Physical Assessment/Monitoring
Check ordered labs and report abnormalities.
Dosage Forms: US
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Capsule, Oral:
Avodart: 0.5 mg
Generic: 0.5 mg
Dosage Forms: Canada
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Capsule, Oral:
Avodart: 0.5 mg
Generic: 0.5 mg
Anatomic Therapeutic Chemical (ATC) Classification
- G04CB02
Generic Available (US)
Yes
Pricing: US
Capsules (Avodart Oral)
0.5 mg (per each): $7.93
Capsules (Dutasteride Oral)
0.5 mg (per each): $1.70 - $6.05
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
Dutasteride is a 4-azo analog of testosterone and is a competitive, selective inhibitor of both reproductive tissues (type 2) and skin and hepatic (type 1) 5α-reductase. This results in inhibition of the conversion of testosterone to dihydrotestosterone and markedly suppresses serum dihydrotestosterone levels.
Pharmacodynamics/Kinetics
Absorption: Absorbed via skin when handling capsules
Distribution: Vd: 300 to 500 L, ~12% of serum concentrations partitioned into semen
Protein binding: 99% to albumin; ~97% to alpha1-acid glycoprotein; >96% to semen protein
Metabolism: Hepatic via CYP3A4 and CYP3A5 isoenzymes (extensive); forms metabolites: 6-hydroxydutasteride has activity similar to parent compound, 4′-hydroxydutasteride and 1,2-dihydrodutasteride are much less potent than parent in vitro
Bioavailability: ~60% (range: 40% to 94%)
Half-life elimination: Terminal: ~5 weeks
Time to peak: 2-3 hours
Excretion: Feces (40% as metabolites, ~5% as unchanged drug); urine (<1% as unchanged drug); ~55% of dose unaccounted for
Pharmacodynamics/Kinetics: Additional Considerations
Geriatric: Dutasteride half-life increases with age.
Local Anesthetic/Vasoconstrictor Precautions
No information available to require special precautions
Effects on Dental Treatment
No significant effects or complications reported
Effects on Bleeding
No information available to require special precautions
Related Information
FDA Approval Date
November 20, 2001
References
<800> Hazardous Drugs—Handling in Healthcare Settings. United States Pharmacopeia and National Formulary (USP 40-NF 35). Rockville, MD: United States Pharmacopeia Convention; 2017:83-102.
Andriole G, Bostwick DG, Brawley OW, et al, “Effect of Dutasteride on the Risk of Prostate Cancer,” N Engl J Med, 2010, 362(13):1192-202.[PubMed 20357281]
Andriole GL, Marberger M, and Roehrborn CG. Clinical usefulness of serum prostate specific antigen for the detection of prostate cancer is preserved in men receiving the dual 5alpha-reductase inhibitor dutasteride. J Urol. 2006;175(5):1657-1662.[PubMed 16600723]
Avodart (dutasteride) [prescribing information]. Research Triangle Park, NC: GlaxoSmithKline; January 2020.
Eun HC, Kwon OS, Yeon JH, et al. Efficacy, safety, and tolerability of dutasteride 0.5 mg once daily in male patients with male pattern hair loss: a randomized, double-blind, placebo-controlled, phase III study. J Am Acad Dermatol. 2010;63(2):252-258.[PubMed 20605255]
Olsen EA, Hordinsky M, Whiting D, Stough D, Hobbs S, Ellis ML, Wilson T, Rittmaster RS; Dutasteride Alopecia Research Team. The importance of dual 5alpha-reductase inhibition in the treatment of male pattern hair loss: results of a randomized placebo-controlled study of dutasteride versus finasteride. J Am Acad Dermatol. 2006;55(6):1014-1023.[PubMed 17110217]
US Department of Health and Human Services; Centers for Disease Control and Prevention; National Institute for Occupational Safety and Health. NIOSH list of antineoplastic and other hazardous drugs in healthcare settings 2016. http://www.cdc.gov/niosh/topics/antineoplastic/pdf/hazardous-drugs-list_2016-161.pdf. Updated September 2016. Accessed October 5, 2016.
Brand Names: International
Armonia (IL); Avidart (ES); Avodart (AE, AR, AT, AU, BB, BE, BG, BH, BM, BR, BS, BZ, CH, CL, CN, CO, CR, CY, CZ, DE, DK, DO, EC, EE, EG, FI, FR, GB, GR, GT, GY, HK, HN, HR, ID, IE, IL, IS, IT, JM, JO, KR, KW, LB, LK, LT, LU, LV, MT, MX, MY, NI, NL, NO, NZ, PA, PE, PH, PL, PR, PT, QA, RO, RU, SA, SE, SG, SI, SK, SR, SV, TH, TR, TT, TW, UA, VN); Avolve (JP); Bengiride (EG); Duagen (GR); Duavo (KR); Duprost (IN, LK); Dutagen (KR); Dutamax (BD); Dutamex (LK); Dutasia (PH); Dutaslow (EG); Dutesmol (KR); Neodart (KR); Prostasil (PE); Prostatex (BE); Quedute (IE); Urodart (BD); Uroka (TH); Zagallo (JP)
Last Updated 8/28/20
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