Types of hepatic damage that may develop during terbinafine therapy include:
(1) hepatocellular hepatitis
(2) cholestatic hepatitis
(3) mixed hepatocellular-cholestatic hepatitis
(4) autoimmune hepatitis
(5) fulminant necrosis
Risk factors for terbinafine-associated hepatotoxicity:
(1) pre-existing liver disease
(2) continued therapy after the appearance of liver dysfunction
It is recommended that a patient who is to be started on terbinafine for the treatment of onychomycosis should have fungal cultures performed on the nail to confirm the diagnosis prior to initiating therapy.
Clinical findings may include:
(1) malaise and/or fatigue
(2) jaundice
(3) pruritus
(4) anorexia
(5) right upper quadrant abdominal pain
(6) nausea and vomiting
(7) dark urine and/or pale stools
The onset of hepatotoxicity is usually 4 to 6 weeks after initiation of systemic therapy. Liver function tests should be performed before starting therapy, 4 to 6 weeks later and if the patient develops liver disease.
The liver disease usually resolves after the terbinafine is discontinued but It may take up to 2 years for a full recovery to occur.
