Griseofulvin

Griseofulvin is an antimycotic (antifungal) medicine that is used to treat fungal infections of the skin, hair and nails. It is effective against various species of dermatophytes such as Trichophyton (cause of athlete's foot, ringworm), Microsporum and Epidermophyton.

Griseofulvin works by disrupting the structure and function of the microtubules of the fungal cell skeleton, which prevents the fungal cells from dividing. This stops the spread of infection, making fungal cells more vulnerable to the host's immune system.

Indications Griseofulvina

1. Dermatophytosis (trichophytosis, microsporia, epidermophytosis) are fungal infections of the skin caused by dermatophytes that affect the skin, hair and nails.
2. Onychomycosis (fungal nail infections) is a disease in which fungi affect the nail plate, causing its deformation, discoloration and peeling.
3. Trichophytosis (lichen) - fungal infections of the scalp, which can lead to baldness and inflammation skin.

Release form

Griseofulvin is usually available in the form of tablets or capsules for oral use.

Pharmacodynamics

The mechanism of action of griseofulvin is that it is embedded in the structure of keratin (the protein that makes up the bulk of skin, hair and nails), making it less accessible to fungi and preventing their growth and reproduction. This is especially important for treating infections caused by dermatophytes such as trichophytosis, microsporia and athlete's foot, which affect the skin, hair and nails.

Pharmacokinetics

• Absorption: Griseofulvin is absorbed from the gastrointestinal tract, primarily from the duodenum. Eating food may increase its absorption.
• Metabolism: The drug undergoes significant metabolism in the liver, including hydroxylation and demethylation.
• Excretion: Metabolites are excreted primarily through bile and feces. A small amount is excreted through the kidneys.
• Half-life: The half-life of griseofulvin can be quite long, requiring a long course of treatment.
• Time to reach maximum blood concentration (Tmax): Tmax is usually 4 to 5 hours after taking the drug.
• Protein binding: Griseofulvin is highly bound to plasma proteins, mainly albumin.
• Duration of action: The long-term action of griseofulvin is due to its accumulation in keratinized tissues such as skin, hair and nails.

Dosing and administration

Method of administration and dosage

The dosage and route of administration of griseofulvin may vary depending on the form of the drug (tablets, suspension), the type of infection, the patient's age and weight. It is important to follow your doctor's instructions and the directions on the drug package. Below are general recommendations:

1. For adults and children over 12 years old:
   • The usual dose is 500 mg to 1000 mg per day, depending on the type and severity of the infection.
   • The dosage can be divided into several doses throughout the day.
2. For children weighing less than 50 kg:
   • The usual dose is 10 mg to 20 mg per kilogram of body weight per day.
   • The dose is also divided into several doses.

Method of administration

• Griseofulvin should be taken with a fatty meal to improve its absorption.
• It is recommended to drink plenty of fluids throughout the day to help eliminate the drug from the body.
• The duration of treatment depends on the location and severity of the infection, but the course usually lasts several weeks to several months, since fungal infections respond slowly to treatment.

Note

• Do not interrupt treatment or change dosage without consulting your doctor, even if symptoms improve.
• Completing the full course of treatment helps prevent recurrence of the infection.

Use Griseofulvina during pregnancy

Griseofulvin is not recommended for use during pregnancy due to the potential risk to the developing fetus. Here are the main points to consider:

Risks to the fetus:

Griseofulvin has been shown to be teratogenic in animal studies, meaning it can cause birth defects in fetuses. Although direct evidence in humans is limited, due to data from animal studies and potential risks, griseofulvin is considered unsafe for use during pregnancy.

Recommendations for pregnant women:

• Avoid: Pregnant women should avoid the use of griseofulvin. If a woman plans to become pregnant or discovers that she is pregnant while taking this drug, she should consult her doctor immediately.
• Consult with your doctor: Your doctor may suggest alternative treatments for yeast infections that are safer to use during pregnancy.

Other precautions:

• Contraception: Women of reproductive potential taking griseofulvin are advised to use effective contraception during treatment and for a period after treatment to avoid pregnancy.
• Monitoring: If pregnancy occurs during treatment with griseofulvin, it is important to carefully monitor the health of both mother and fetus.

Contraindications

1. Known individual intolerance: People with a known individual intolerance to griseofulvin or other antifungals in this class should avoid its use.
2. Hepatic Impairment: Because griseofulvin is metabolized by the liver, its use may be contraindicated in patients with hepatic impairment or other liver disease.
3. Porphyria: Griseofulvin may worsen the symptoms of porphyria and should be used with caution in patients with this disease.
4. Pregnancy and breast-feeding: The use of griseofulvin during pregnancy and breast-feeding may be contraindicated or require special attention. The doctor must decide how necessary the use of the drug is in these cases.
5. Pediatrics: The use of griseofulvin in children may be limited and should be used with caution in children, especially infants and young children.
6. Alcohol: It is recommended to avoid drinking alcohol during treatment with griseofulvin, as this may increase the negative side effects of the drug on the liver.

Side effects Griseofulvina

1. Allergic reactions: In rare cases, griseofulvin can cause serious allergic reactions, including hives, itching, swelling of the face or lips, and difficulty breathing.
2. Gastrointestinal disorders: The most common side effects include nausea, vomiting, diarrhea and abdominal pain.
3. Headaches and dizziness: Some patients report headaches and dizziness while taking the drug.
4. Fatigue: Griseofulvin may cause you to feel tired or weak.
5. Photosensitivity: One of the known side effects of griseofulvin is increased sensitivity to sunlight, which can lead to burns or redness of the skin when exposed to ultraviolet light.
6. Menstrual disorders: In women, griseofulvin may cause some changes in the menstrual cycle.
7. Effects on the Liver: Because griseofulvin is metabolized in the liver, it may affect liver function as evidenced by changes in liver enzymes.
8. Mental changes: In very rare cases, griseofulvin may cause mental changes, including confusion, anxiety, or depression.

Overdose

1. Gastrointestinal symptoms: Nausea, vomiting, diarrhea and abdominal pain are often the first signs of overdose.
2. Neurological symptoms: Dizziness, headache, fatigue and even confusion may occur with high doses of the drug.
3. Skin reactions: Griseofulvin may cause increased photosensitivity, which is aggravated by overdose, leading to severe skin burns when exposed to sunlight.
4. Allergic reactions: In rare cases, serious allergic reactions may occur, including hives, swelling and difficulty breathing.

Interactions with other drugs

1. Antifungal drugs: Combining griseofulvin with other antifungal drugs may increase or decrease the effect of the other drugs.
2. Anticonvulsants: Griseofulvin may reduce the effectiveness of anticonvulsants such as carbamazepine and phenytoin.
3. Antineoplastic drugs: Interactions with antineoplastic drugs such as cyclophosphamide may increase their toxicity.
4. Antibiotics: Combination with antibiotics such as tetracyclines and ampicillin may reduce their effectiveness.
5. Contraception: Griseofulvin may reduce the effectiveness of oral contraceptives, so the use of alternative methods of contraception is recommended.
6. Drugs metabolized by the liver: Griseofulvin may affect the metabolism of other drugs metabolized by the liver, which may result in changes in their blood concentrations.