Statin Therapy Can Be Continued When Taking Terbinafine
It is not necessary to hold statin therapy when taking terbinafine as terbinafine has minimal drug-drug interactions with statins and does not significantly inhibit the cytochrome P450 3A4 enzyme that metabolizes most statins. 1, 2
Drug Interaction Profile of Terbinafine
- Terbinafine is an oral antifungal agent commonly used for treating onychomycosis (fungal nail infections) 1
- Unlike azole antifungals (such as itraconazole), terbinafine has minimal drug-drug interactions and is generally well-tolerated in patients taking multiple medications 2
- Terbinafine primarily affects the cytochrome P450 2D6 isoenzyme, not the CYP3A4 enzyme that metabolizes most statins 1, 3
- No contraindications exist for the concurrent use of terbinafine and statins 2
Contrast with Other Antifungal Medications
- Azole antifungals (itraconazole, fluconazole) are potent inhibitors of CYP3A4 and can significantly increase statin levels, potentially causing myopathy or rhabdomyolysis 4, 5
- A case report documented statin-associated rhabdomyolysis triggered by itraconazole (not terbinafine) due to CYP3A4 inhibition 4
- When antifungal treatment is needed for patients on statins, terbinafine is actually preferred over azole antifungals due to its favorable drug interaction profile 4, 2
Monitoring Recommendations
- While no specific interaction exists between statins and terbinafine, general monitoring for statin therapy should continue as usual 1:
- Evaluate muscle symptoms and CK levels at baseline and during follow-up visits
- Monitor for headache, dyspepsia, and other common statin side effects
- Check liver function tests (ALT/AST) initially, after 12 weeks, and then annually
Special Considerations
- Patients with risk factors for statin-associated myopathy should be monitored more carefully regardless of concurrent medications 1:
- Advanced age (especially >80 years)
- Small body frame and frailty
- Multisystem disease (especially chronic renal insufficiency)
- Multiple medications
- Perioperative periods
Clinical Decision Making
- Terbinafine is actually the preferred antifungal agent for patients on statin therapy due to its minimal drug interaction potential 2
- In a large postmarketing surveillance study with over 25,000 patients (42.8% taking concomitant medications), terbinafine revealed no new drug-drug interactions 2
- Some combinations of statins and terbinafine have even shown synergistic effects against dermatophytes in laboratory studies, potentially enhancing antifungal efficacy 6
In conclusion, unlike azole antifungals which require statin dose adjustment or temporary discontinuation, terbinafine can be safely administered with statins without the need to hold statin therapy, making it the preferred antifungal option for patients on statins.