Terbinafine and Leg Pain
Leg pain is not a recognized or documented adverse effect of terbinafine based on current clinical guidelines and safety data.
Known Adverse Effect Profile of Terbinafine
The established side effects of terbinafine do not include musculoskeletal complaints such as leg pain. The documented adverse events are:
Common Side Effects
- Gastrointestinal disturbances (nausea, diarrhea, taste disturbance) occur in 49% of reported side effects 1
- Dermatological reactions (rash, pruritus, urticaria, eczema) occur in 23% of reported side effects 1
- Terbinafine is generally well tolerated, with adverse events experienced by only 10.5% of recipients in post-marketing surveillance 2
Serious but Rare Adverse Effects
- Hepatotoxicity, particularly in patients with pre-existing liver disease 3, 1
- Rare hematologic effects, including occasional isolated neutropenia 3
- Severe cutaneous reactions including Stevens-Johnson syndrome and toxic epidermal necrolysis 1
- Taste and smell disturbances that can potentially be permanent 1
Clinical Interpretation
If a patient on terbinafine presents with leg pain, alternative etiologies should be investigated rather than attributing it to the medication. The absence of leg pain or any musculoskeletal symptoms in comprehensive safety reviews 1, 2 and clinical practice guidelines 3 strongly suggests this is not a drug-related effect.
Recommended Approach
- Evaluate for other causes of leg pain (vascular, neurologic, orthopedic, infectious)
- Review concomitant medications for potential drug interactions, particularly with cardiovascular drugs 4
- Consider whether the underlying fungal infection itself (such as severe tinea pedis) could be causing discomfort 3
- Do not discontinue terbinafine based solely on leg pain without identifying an alternative cause
Monitoring Considerations During Terbinafine Therapy
The British Association of Dermatologists recommends monitoring for:
- Hepatic function with baseline liver function tests, particularly if treatment extends beyond one month 1
- Complete blood count in patients with history of hematological abnormalities 1
- Renal function awareness, as terbinafine is contraindicated in patients with creatinine clearance ≤50 mL/min 1
None of these monitoring recommendations include assessment for musculoskeletal symptoms, further supporting that leg pain is not an expected adverse effect of terbinafine.