Terbinafine is a medication used to combat fungal infections. It belongs to a class of drugs known as antifungals, which work by targeting and eliminating fungal organisms. This medication is available in different forms, including oral tablets and topical applications like creams or ointments.
Conditions Terbinafine Treats
Terbinafine is primarily used to treat infections caused by dermatophytes, a type of fungus that commonly affects the skin, hair, and nails. These infections include onychomycosis, which impacts fingernails and toenails, leading to discoloration and thickening. It also addresses tinea pedis, commonly known as athlete’s foot, a fungal infection affecting the feet.
The medication is also effective against tinea cruris, often called jock itch, which involves fungal growth in the groin area. Ringworm, or tinea corporis, an infection that causes a circular, itchy rash on the body, is another condition treated by terbinafine. Tinea capitis, a fungal infection of the scalp particularly prevalent in children, also responds to terbinafine.
How Terbinafine Works
Terbinafine functions by interfering with a process within fungal cells. It belongs to the allylamine class of antifungals, which act by inhibiting an enzyme called squalene epoxidase. This enzyme plays a role in the synthesis of ergosterol, a component of the fungal cell membrane.
By blocking squalene epoxidase, terbinafine prevents the formation of the fungal cell membrane. This disruption leads to an accumulation of squalene inside the fungal cell, which is toxic to the fungus. The resulting damage to the cell membrane causes the fungal cell to die.
Effectiveness for Fungal Infections
Terbinafine demonstrates effectiveness across various fungal infections, particularly those caused by dermatophytes. For onychomycosis, or fungal nail infections, oral terbinafine is frequently prescribed due to its ability to reach the infection deep within the nail bed. Treatment duration for toenail onychomycosis lasts 12 weeks, while fingernail infections may require 6 weeks of therapy. Complete clearing of the nail may take several months as the healthy nail grows out.
For skin infections like tinea pedis (athlete’s foot), tinea cruris (jock itch), and tinea corporis (ringworm), terbinafine can be used topically or orally depending on the severity and extent of the infection. Oral treatment for these conditions is 2 to 6 weeks for tinea pedis and 2 to 4 weeks for tinea cruris and tinea corporis. Topical formulations are sufficient for localized and less severe cases.
Tinea capitis, a fungal infection of the scalp, is treated with oral terbinafine. This infection is more common in children and requires a treatment period of 6 weeks. The medication works systemically to target the fungus in hair follicles.
Important Considerations for Use
Oral terbinafine tablets are taken once daily, usually as a 250 mg dose, for systemic infections like nail fungus. Topical creams or gels are used for superficial skin infections. The duration of treatment varies from a few weeks for skin infections to several months for nail infections; completing the full prescribed course is important.
While well-tolerated, terbinafine can cause common side effects. These include gastrointestinal issues such as nausea, diarrhea, or an upset stomach, as well as headaches or a skin rash. Some individuals might experience changes in their sense of taste or smell.
More serious side effects, though rare, can occur and warrant immediate medical attention. These include liver problems, such as persistent nausea, upper stomach pain, yellowing of the skin or eyes (jaundice), or unusually dark urine. Severe skin reactions, characterized by blistering or peeling skin, and allergic reactions are also possible. Patients should always consult a healthcare professional before starting terbinafine to discuss potential risks and monitoring requirements.