Griseofulvin is an oral antifungal medication that treats fungal infections. It stops fungal growth rather than killing fungi directly. It works systemically, traveling through the bloodstream to reach infection sites.
How Griseofulvin Works
Griseofulvin interferes with fungal cell division. The drug binds to tubulin, a protein that forms microtubules, which are structural components within cells. Microtubules are essential for many cellular processes, including the formation of the mitotic spindle, a structure that separates chromosomes during cell division (mitosis). By binding to tubulin, griseofulvin disrupts the proper assembly of these microtubules, which inhibits the fungal cell’s ability to divide and multiply.
Griseofulvin selectively targets fungal cells. The drug shows a greater affinity for fungal tubulin compared to human tubulin, allowing it to disrupt fungal mitosis without significantly affecting human cellular mechanisms. Once absorbed, griseofulvin tends to accumulate in keratin-producing cells found in the skin, hair, and nails.
As new keratinized tissues grow, griseofulvin becomes incorporated into them, making the newly formed skin, hair, and nails resistant to fungal invasion. This accumulation helps deliver antifungal activity directly to the infection site and prevents reinfection as treated tissues shed.
What Griseofulvin Treats
Griseofulvin is primarily used to treat dermatophyte infections, which are fungal infections affecting the skin, hair, and nails. These infections are commonly known as tinea infections. Examples include:
Tinea corporis (ringworm of the body)
Tinea pedis (athlete’s foot)
Tinea cruris (jock itch)
Fungal infections of the scalp (tinea capitis)
Fungal infections of the nails (onychomycosis)
Its effectiveness against these infections stems from its accumulation in keratinized tissues, creating an unfavorable environment for fungal growth. Griseofulvin is often prescribed when topical antifungal treatments have not been effective or are not suitable for the infection’s location or severity. It is considered for extensive or difficult-to-treat infections of the skin, hair, and nails.
Important Considerations for Taking Griseofulvin
For optimal absorption, griseofulvin should be taken with or after a fatty meal. Foods like whole milk, ice cream, or a cheeseburger can significantly enhance the body’s uptake of the medication. This improved absorption helps the medication combat the infection more effectively. It is available in various oral forms, including tablets, capsules, and a liquid suspension.
Common side effects can include gastrointestinal upset such as nausea, vomiting, or diarrhea, as well as headaches and dizziness. Some individuals may also experience skin rashes or increased sensitivity to sunlight (photosensitivity). Patients are advised to use sun protection, like protective clothing and sunscreen, when outdoors to minimize this risk.
Griseofulvin can interact with other medications, potentially reducing their effectiveness or increasing side effects. It may decrease the effectiveness of hormonal contraceptives, such as birth control pills, patches, or injections. An alternative non-hormonal birth control method should be used during treatment and for a period afterward, usually for at least one month after the last dose. Alcohol consumption should be avoided or used cautiously as it may lead to symptoms like flushing, rapid heart rate, or increased drowsiness. The drug can also interact with warfarin, a blood thinner, potentially reducing its effect; therefore, monitoring of blood clotting times may be necessary.
Treatment duration can vary considerably depending on the type and location of the fungal infection. Skin infections might require treatment for 2 to 4 weeks, while infections of the hair and scalp may take 4 to 8 weeks. Fungal nail infections often necessitate much longer courses, ranging from 3 to 4 months for fingernails and at least 6 months for toenails, sometimes extending up to a year or more. It is important to complete the full prescribed course of treatment, even if symptoms improve, to prevent the infection from returning.