What analgesics are safe and recommended for patients with hypertrophic cardiomyopathy who are taking Camzyos (mavacamten)?

Pain Medication Management in Patients on Camzyos

Most standard analgesics including acetaminophen, NSAIDs, and opioids can be used safely in patients taking Camzyos (mavacamten), but you must avoid any pain medications that are moderate-to-strong CYP2C19 or CYP3A4 inhibitors/inducers due to life-threatening drug interaction risks.

Key Drug Interaction Principles

The critical issue with Camzyos is not the pain itself, but the metabolic pathway interactions. Mavacamten is primarily metabolized by CYP2C19 and CYP3A4 enzymes 1. Drug interactions through these pathways can either:

• Increase mavacamten levels → risk of heart failure from excessive LVEF reduction
• Decrease mavacamten levels → loss of therapeutic effectiveness

Contraindicated Analgesics (AVOID COMPLETELY)

Do not use any moderate-to-strong CYP2C19 or strong CYP3A4 inhibitors, as these are explicitly contraindicated by the FDA label 1. Common pain medications to avoid include:

• Omeprazole and esomeprazole (often used for NSAID gastroprotection) - these are moderate-to-strong CYP2C19 inhibitors
• Cimetidine (H2 blocker sometimes used with analgesics) - CYP2C19 inhibitor 1

Safe Analgesic Options

First-line choices:

• Acetaminophen - No significant CYP2C19/3A4 interaction; safe at standard doses
• NSAIDs (ibuprofen, naproxen, ketorolac) - No significant CYP2C19/3A4 interaction; monitor for fluid retention as diuretics should be used cautiously in obstructive HCM 2
• Opioids (morphine, hydromorphone, oxycodone) - Generally safe; most are not significant CYP2C19/3A4 inhibitors

Use with caution and dose adjustment:

• Tramadol - Weak CYP2C19 inhibitor; if used, reduce Camzyos dose by one level (15mg→10mg; 10mg→5mg; 5mg→2.5mg) 1
• Codeine - Requires CYP2C19 for activation; may have reduced efficacy in patients on Camzyos but not contraindicated

Critical Monitoring Requirements

When prescribing any analgesic to a patient on Camzyos:

1. Check LVEF before and during treatment - Camzyos requires regular echocardiographic monitoring per REMS protocol 1
2. Interrupt Camzyos if LVEF drops <50% at any visit 1
3. Avoid vasodilators - The 2024 AHA/ACC guidelines note that discontinuation of vasodilators may be reasonable in obstructive HCM as they can worsen outflow obstruction 2
4. Consider intercurrent illness - Delay dose increases or consider interrupting Camzyos during serious infections or other acute illnesses that may impair systolic function 1

Special Considerations for HCM Patients

Beyond drug interactions, remember that patients with obstructive HCM on Camzyos have specific hemodynamic considerations:

• Avoid volume depletion - Use NSAIDs cautiously as they can cause fluid retention, but aggressive diuresis is also problematic in obstructive HCM 2
• Maintain adequate preload - If hypotension occurs with pain/illness, use phenylephrine or other vasoconstrictors without inotropic activity 2
• Beta-blockers are first-line for HCM - Most patients on Camzyos are already on beta-blockers 2, which may mask tachycardia from pain

Common Pitfalls to Avoid

1. Over-the-counter medications - Patients often don't report OTC analgesics or gastroprotective agents. Specifically ask about omeprazole, esomeprazole, and cimetidine 1
2. Combination products - Many OTC pain medications contain multiple ingredients; check all components
3. Gastroprotection with NSAIDs - If needed, use famotidine or ranitidine instead of omeprazole/esomeprazole
4. Assuming all opioids are safe - While most are safe, always verify the specific agent's metabolic pathway

The bottom line: Standard analgesics (acetaminophen, most NSAIDs, most opioids) are safe, but you must actively screen for and avoid CYP2C19/3A4 inhibitors, particularly the common gastroprotective agents omeprazole and esomeprazole.