Terbinafine Use in Diffuse Ringworm with Elevated SGOT
I would not give terbinafine to this patient with SGOT of 67.41 (nearly 2x upper limit of normal), as the FDA explicitly states that terbinafine is not recommended for patients with chronic or active liver disease, and treatment should be discontinued if biochemical evidence of liver injury develops. 1
Risk Assessment for This Patient
Your patient's SGOT (AST) of 67.41 represents approximately 1.9 times the upper limit of normal, which exceeds the "mild elevation" threshold discussed in guidelines:
The FDA drug label clearly states that terbinafine should be immediately discontinued in case of elevation of liver function tests, and is not recommended for patients with chronic or active liver disease. 1
While the British Association of Dermatologists distinguishes between isolated mild transaminase elevations (which don't preclude therapy) and active liver disease, they specifically reference ALT of 50 (1.25x ULN) as an example of mild elevation that could potentially be monitored. 2
Your patient's elevation is substantially higher at nearly 2x normal, which raises concern for underlying hepatic pathology rather than isolated mild elevation. 2
Critical Next Steps Before Any Treatment
Before prescribing any systemic antifungal, you must:
Investigate the cause of the elevated SGOT - check for viral hepatitis, alcohol use, fatty liver disease, autoimmune hepatitis, or other hepatotoxic medications. 1
Obtain complete hepatic panel including ALT, alkaline phosphatase, total bilirubin, and GGT to characterize the pattern of liver injury. 1
Assess for clinical signs of liver disease including jaundice, ascites, coagulopathy, or encephalopathy. 1
Alternative Treatment Options for Diffuse Ringworm
For this patient with elevated transaminases and diffuse tinea corporis, I recommend topical antifungal therapy as first-line treatment:
Topical Therapy (Preferred)
Use topical azoles such as clotrimazole, miconazole, or ketoconazole cream applied twice daily for 2-4 weeks. 2
Terbinafine 1% cream can be used topically (applied once or twice daily) without the hepatotoxicity risk of oral formulation. 3
For extensive involvement, consider ciclopirox solution or cream applied to affected areas. 2, 3
Systemic Alternatives (If Topical Fails)
If topical therapy proves inadequate for diffuse disease:
Itraconazole is the first-line systemic alternative, though it also carries hepatotoxicity risk and requires normal baseline liver function. 2
Given your patient's already elevated SGOT, itraconazole would require hepatology consultation and close monitoring, as one case report documented increased liver enzymes with itraconazole in a patient with tinea corporis. 3
Fluconazole is another option but similarly requires hepatic monitoring and has documented hepatotoxicity. 2
If You Must Consider Terbinafine
Only after hepatology consultation and if the elevated SGOT is determined to be transient/unrelated to chronic liver disease:
Obtain hepatologist clearance before initiating therapy. 4
Limit treatment duration to less than 6 weeks rather than standard 12-16 weeks. 4
Monitor liver function tests weekly during treatment. 4
Educate patient to immediately report nausea, anorexia, fatigue, vomiting, right upper abdominal pain, jaundice, dark urine, or pale stools. 1
One case report documented safe use of terbinafine in a patient with stable autoimmune hepatitis using these precautions, but this was for limited tinea corporis, not diffuse disease. 4
Critical Warnings About Terbinafine Hepatotoxicity
Cases of liver failure leading to liver transplant or death have occurred with terbinafine in patients both with and without pre-existing liver disease. 1
The severity of hepatic events is worse in patients with active or chronic liver disease. 1
Hepatotoxicity can present as mixed hepatocellular-cholestatic injury, with some cases showing progressive cholestatic injury with severely elevated bilirubin and coagulopathy. 5
Drug-induced liver injury from terbinafine is idiosyncratic and can develop slowly, requiring longitudinal monitoring even after discontinuation. 5