From the Guidelines
Terbinafine can cause several side effects, including gastrointestinal disturbances, skin reactions, and rare but serious liver problems, and patients should be aware of these potential risks before starting treatment. The most common side effects of terbinafine include gastrointestinal events, such as nausea, diarrhea, or taste disturbance, which occur in about 49% of patients, and dermatological events, such as rash, pruritus, urticaria, or eczema, which occur in approximately 23% of users 1. More serious but rare side effects include liver problems, such as elevated liver enzymes or hepatitis, which occur in less than 1% of patients, and severe skin reactions like Stevens-Johnson syndrome, which are extremely rare but potentially life-threatening 1.
Key Side Effects
- Gastrointestinal disturbances: nausea, diarrhea, taste disturbance
- Skin reactions: rash, itching, hives, urticaria, eczema
- Liver problems: elevated liver enzymes, hepatitis
- Severe skin reactions: Stevens-Johnson syndrome, toxic epidermal necrolysis
- Blood disorders: neutropenia, thrombocytopenia
- Other side effects: headaches, joint or muscle pain, depression It is essential to monitor liver function and complete blood counts in patients with a history of heavy alcohol consumption, hepatitis, or hematological abnormalities before starting terbinafine treatment 1. Additionally, patients should be warned about the potential risk of permanent taste disturbance, which is a rare but reported side effect of terbinafine 1.
From the FDA Drug Label
What are the possible side effects of terbinafine? Terbinafine may cause serious side effects, including: liver problems that can lead to the need for liver transplant, or death. The most common side effects of terbinafine include: headache, diarrhea, rash, dyspepsia, liver enzyme abnormalities, pruritus, taste disturbance, nausea, abdominal pain, and flatulence.
The possible side effects of terbinafine include liver problems, taste disturbance, smell disturbance, depressive symptoms, and severe neutropenia. Common side effects include headache, diarrhea, rash, dyspepsia, liver enzyme abnormalities, pruritus, nausea, abdominal pain, and flatulence 2.
- Serious side effects may include liver problems, Stevens-Johnson syndrome, toxic epidermal necrolysis, erythema multiforme, exfoliative dermatitis, bullous dermatitis, and drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome 2.
- Patients should be monitored for signs of liver injury and depressive symptoms.
- If any of these side effects occur, the patient should stop taking terbinafine and contact their doctor immediately.
From the Research
Terbinafine Side Effects
- Terbinafine has been associated with severe liver injury, with symptoms including jaundice, flu-like symptoms, dark urine, and pruritus 3
- The mean duration of terbinafine treatment until onset of symptoms was 30.2 days, with patients experiencing symptoms for a mean of 14.8 days before seeking medical attention 3
- Liver toxicity has also been reported, with cases of severe cholestatic hepatitis associated with terbinafine use 4
- The mechanism underlying terbinafine hepatotoxicity may involve the allylic aldehyde metabolite of terbinafine, 7-dimethylhept-2-ene-4-ynal (TBF-A) 4
- Cutaneous adverse effects have also been reported, including erythema multiforme, erythroderma, severe urticaria, pityriasis rosea, and worsening of pre-existing psoriasis 5
- Monitoring of liver function tests is not recommended, but patients should be advised to discontinue treatment and seek medical attention if symptoms of liver injury occur 3
- Periodic monitoring of liver biochemistry and clinical assessment may be useful in detecting abnormal hepatic function early 4, 6
- The prognosis for severe acute liver injury caused by terbinafine is often good with appropriate treatment, and liver function assessment before treatment and periodic monitoring 4-6 weeks after initiation of treatment is recommended 6