Isoniazid - Comprehensive Usage Guide: instructions, indications, composition, side effects
Composition
- Active Ingredient: Isoniazid
- Excipients: May include microcrystalline cellulose, sodium starch glycolate, magnesium stearate, and other inactive ingredients depending on the formulation.
Official Forms
- Tablets: Available in various strengths, including 100 mg and 300 mg tablets.
Pharmacological Group
Isoniazid belongs to the pharmacological group of antituberculosis agents (ATC code: J04AC01).
Pharmacological Properties
- Pharmacodynamics: Isoniazid inhibits mycolic acid synthesis in the cell wall of Mycobacterium tuberculosis, leading to bacterial cell death.
- Pharmacokinetics: Following oral administration, isoniazid is rapidly absorbed from the gastrointestinal tract. It is metabolized in the liver and excreted primarily in the urine.
Indications
Isoniazid is indicated for the treatment of tuberculosis (TB) and for the prevention of TB in individuals with latent TB infection.
Contraindications
Isoniazid is contraindicated in individuals with:
- Known hypersensitivity to isoniazid or any component of the formulation.
- Severe liver disease or a history of drug-induced hepatitis.
- Concurrent use of alcohol, as it may increase the risk of hepatotoxicity.
Interactions
Isoniazid may interact with other medications, including:
- Drugs that inhibit or induce hepatic enzymes, potentially altering plasma concentrations of isoniazid and other concomitant medications.
Specifics of Use
- Isoniazid tablets should be taken orally on an empty stomach, preferably 1 hour before or 2 hours after meals.
- The dosage and duration of therapy depend on the type and severity of TB, as well as patient factors such as age and renal function.
Pregnancy and Breastfeeding
- Isoniazid is generally considered safe for use during pregnancy, especially in cases where the benefits outweigh the risks.
- It is excreted in breast milk, but the benefits of breastfeeding may outweigh the potential risks in treated mothers with active TB.
Dosage and Administration
- Dosage adjustments may be necessary in patients with hepatic impairment to prevent drug accumulation and minimize the risk of adverse effects.
Overdose
In case of overdose, supportive measures should be initiated, and medical attention should be sought immediately. Symptoms of overdose may include nausea, vomiting, and dizziness.
Side Effects
Common side effects of isoniazid may include:
- Peripheral neuropathy
- Hepatotoxicity
- Gastrointestinal disturbances (e.g., nausea, vomiting, abdominal pain)
Storage and Shelf Life
Isoniazid tablets should be stored at room temperature (15-30°C) in a dry place, protected from light and moisture. The expiration date should be checked before use.