Contraindications to Oral Terbinafine
Oral terbinafine is absolutely contraindicated in patients with a history of allergic reaction to the drug due to anaphylaxis risk, and should not be used in patients with active or chronic liver disease. 1
Absolute Contraindications
Hypersensitivity
- History of allergic reaction to oral terbinafine is the only FDA-labeled absolute contraindication due to risk of anaphylaxis 1
- Rare but serious hypersensitivity reactions including Stevens-Johnson syndrome, toxic epidermal necrolysis, and DRESS syndrome have been documented 2
Hepatic Disease
- Active or chronic liver disease represents a strong clinical contraindication, as the British Association of Dermatologists explicitly states systemic terbinafine is not recommended in these patients 2
- Rare but serious hepatic toxicity has been reported, occurring predominantly in patients with pre-existing liver disease 2
- Liver failure leading to transplant or death has occurred with oral terbinafine use 1
Relative Contraindications and High-Risk Populations
Severe Renal Impairment
- Terbinafine clearance is significantly decreased in severe kidney disease, making this a practical contraindication 2
- The British Association of Dermatologists identifies renal impairment as a contraindication, as terbinafine is primarily cleared by the kidneys 3
- Alternative topical treatments (amorolfine, ciclopirox) should be considered in patients with renal impairment 3
Pediatric Use
- Terbinafine is not licensed for treating pediatric onychomycosis, requiring baseline monitoring if use is considered 2
Important Clinical Caveats
Populations Requiring Baseline Monitoring
If terbinafine must be used despite concerns, baseline liver function tests and complete blood count are mandatory in patients with: 2
- History of heavy alcohol consumption
- History of hepatitis
- Hematological abnormalities
- Children (as noted above)
Severe Neutropenia Risk
- Treatment should be discontinued if neutrophil count drops to ≤1,000 cells/mm³ 1
Permanent Adverse Effects Warning
- Taste and smell disturbances can be permanent, requiring patient counseling before initiation 2, 1
- These sensory disturbances warrant drug discontinuation if they occur 1
Exceptional Circumstances
- One case report documented safe use in stable autoimmune hepatitis with extensive precautions: hepatologist consultation, treatment limited to <6 weeks, close monitoring, and patient education 4
- This should not be interpreted as routine practice but rather as an exceptional case requiring multidisciplinary management