Brand Names of Isoniazid
Isoniazid is primarily available as a generic medication, with no major brand names currently marketed in the United States.
Available Formulations
According to the FDA and clinical guidelines, isoniazid is available in the following formulations:
- Oral tablets: 100 mg and 300 mg 1
- Oral syrup: 50 mg/5 ml 2
- Injectable solution: 100 mg/ml for intravenous or intramuscular administration 2
Combination Products
Isoniazid is also available in fixed-dose combination products:
- Rifamate: Combination of rifampin 300 mg and isoniazid 150 mg 2
- Rifinah 300/150: Combination of rifampin 300 mg and isoniazid 150 mg 2
- Rifinah 150/100: Combination of rifampin 150 mg and isoniazid 100 mg 2
- Rifater: Combination of rifampin, isoniazid, and pyrazinamide 3
Pharmaceutical Information
- Isoniazid is chemically known as isonicotinyl hydrazine or isonicotinic acid hydrazide 1
- It appears as a colorless or white crystalline powder or white crystals 1
- It is freely soluble in water, sparingly soluble in alcohol, and slightly soluble in chloroform and ether 1
- Inactive ingredients in tablet formulations include colloidal silicon dioxide, crospovidone, hydrogenated vegetable oil, microcrystalline cellulose, pregelatinized starch, and talc 1
Clinical Considerations
Isoniazid is a first-line agent for tuberculosis treatment with the following characteristics:
- It is bactericidal against rapidly dividing Mycobacterium tuberculosis 2
- Standard adult dosing is 5 mg/kg (maximum 300 mg) daily or 15 mg/kg (maximum 900 mg) for intermittent regimens 2
- Pediatric dosing is 10-15 mg/kg (maximum 300 mg) daily 2
- Isoniazid should be taken 30-60 minutes before food or 2 hours after food for optimal absorption 2
Important Monitoring Considerations
- Pyridoxine (vitamin B6, 10-25 mg/day) supplementation is recommended to prevent peripheral neuropathy, particularly in patients with risk factors such as diabetes, malnutrition, HIV infection, or alcohol dependence 2
- Monitoring for hepatotoxicity is essential, as isoniazid can cause liver injury in approximately 0.1-0.6% of patients 2, 4
- The risk of hepatotoxicity increases with age, alcohol consumption, and when combined with other hepatotoxic medications 2
When prescribing isoniazid, clinicians should be aware that it's primarily available as a generic medication rather than under specific brand names in current practice.