Allison's Pearls

General Concepts 

• All patients on long-acting pain medications must have PRN short-acting pain medication for breakthrough

• In patients admitted for a pain crisis, continue home long-acting pain regimen if possible. IV pain medications or PCA (bolus dose only, no continuous) can be added on top of long-acting regimen.

o   If patient cannot continue home long-acting regimen, ask pharmacist about converting this to basal PCA rate or alternative long-acting strategy

• Patients should NOT receive multiple long-acting pain medications (oral extended-release pain medications, fentanyl patch, continuous rate on PCA, methadone, etc)

• If pain does not improve with short-acting pain medication – dose of short-acting med should be increased

• If long-acting pain regimen is increased, short-acting (breakthrough) medication should not be decreased – maintain or increase short-acting dose

Common Opioid Conversions 

Oral morphine 15 mg = oral hydrocodone 15 mg (1:1 conversion)

Oral morphine 15 mg = oral oxycodone 10 mg (3:2 conversion) 

Oral morphine 15 mg = oral hydromorphone 4 mg (4:1 conversion)

Oral morphine 15 mg = IV morphine 5 mg (3:1 conversion)

Oral hydromorphone 8 mg = IV hydromorphone 1.5 mg (5:1 conversion)

Oral morphine 20 mg = IV hydromorphone 1 mg (20:1 conversion)

IV morphine 6 mg = IV hydromorphone 1 mg (6:1 or 7:1 conversion, variable)

Half-life of short-acting opioids: Morphine and oxycodone >>  hydromorphone

Morphine and oxycodone dosing interval: Q4 or Q6 hrs PRN

Hydromorphone dosing interval: Q3 or Q4 hrs PRN

Patients with NG/G/J tubes

• Extended-release pain medications (Morphine ER/MS Contin, Oxycodone ER/OxyContin) are NEVER crushed.

• Long-acting pain options for these patients are fentanyl patch or methadone.

• Most immediate-release pain meds are available in liquid formulations; morphine also available as a highly concentrated solution (20 mg/mL) for buccal absorption (end of life, bowel obstruction, no access, etc)

Fentanyl patches

• Typically not used in opioid-naïve patients; great long-acting option in those who can’t take PO or with CKD

• Simple dosing calculation (ask your pharmacist to confirm):

Total oral morphine equivalents in 24 hr period / 2 = fentanyl patch strength in mcg

• Do not increase dose <48 hrs after last dose change – patch is 47% absorbed at 24 hrs and 88% at 48 hrs; similar kinetics when removing patch

Non-opioid pain management

• Anti-inflammatory agents (NSAIDs, steroids) are a useful adjunct modality and especially useful for bone pain– normal cautions with NSAIDs apply (avoid if platelets <30K); avoid steroids if on immunotherapy (PD-1, PD-L1, or CTLA-4 antagonists)

• Caution with scheduled acetaminophen or ibuprofen in neutropenic patients due to potential risk of masking neutropenic fever 

Treatment of Breakthrough Nausea/Vomiting

Patients who are admitted for nausea should have at least one scheduled anti-emetic

in addition to PRN anti-emetics

Ondansetron 8 mg PO/IV Q8H

• Avoid if: patient received palonosetron (long-acting 5HT3 inhibitor) in past 48 hrs

• Avoid if: severe constipation/bowel obstruction

• Prochlorperazine 10 mg PO/IV Q6H

Olanzapine 5-10 mg QHS

• Typically dosed QHS due to drowsiness, may be given at other times of day

• Available as tablet or ODT- don’t give your patient IM olanzapine!

• 5 mg dose used for most patients, 10 mg appropriate for young/robust patients

Dexamethasone 4-8 mg daily or BID

• AVOID if: patient receiving immunotherapy (PD-1, PD-L1 or CTLA4 inhibitors)

• Avoid if: already on scheduled steroids as part of chemo regimen

Lorazepam 0.5-1 mg IV/PO Q6H

• Good option in select patients (ask Allison for tips)

 Prevention of Acute and Delayed Chemo-Induced Nausea/Vomiting (CINV)

1-3 drug prophylaxis used based on chemotherapy regimen

• Dexamethasone

• Ondansetron

• Olanzapine

• Fosaprepitant

o   Avoided with ifosfamide-containing regimens

o   NK1 antagonists are not effective for the treatment of CINV

o   Long duration of action – if used, should not be given more frequently than Q72 hrs

My patient has a prolonged QTc – what do I do?

• Do not use Tigan – it is no more effective than placebo in randomized trials

• QTc Fridericia and Framingham are best predictors of cardiac events- use these rather than the Bazett correction.

• Supplement K>4 and Mg >2

• Anti-emetics with lowest risk of QT prolongation: dexamethasone, lorazepam, olanzapine

• IV ondansetron doses of 16 mg and higher have been associated with QT prolongation. Ondansetron may be used with caution (ie use one-time doses or PRN doses rather than scheduled)

• Avoid prochlorperazine

• Talk to your pharmacist about other strategies (yes there are more drugs, but they are either more expensive or have more side effects so talk to Allison prior to prescribing an anti-emetic not listed in this section)

Anti-emetics useful for special situations

• Anticipatory nausea (nausea experienced when thinking about chemo, before chemotherapy cycle begins): Lorazepam

• Motion-associated nausea: scopolamine patch

This document is not an exhaustive list of anti-emetics – talk to your pharmacist about other options!