Isoniazid

Isoniazid is a medication used to treat tuberculosis (TB) and prevent its return. It works by killing the bacteria that cause TB, making it a crucial part of treatment regimens for active and latent TB infections. Isoniazid is often prescribed in combination with other medications, such as rifampin and pyrazinamide, to ensure effective treatment.

How It Works

Isoniazid is a bactericidal agent, meaning it directly kills the bacteria that cause TB. It specifically targets Mycobacterium tuberculosis, M. bovis, and M. kansasii. The medication is activated by bacterial catalase and then inhibits the synthesis of mycoloic acids, an essential component of the bacterial cell wall. This process makes it difficult for the bacteria to survive and multiply.

Uses

Isoniazid is used to treat all forms of tuberculosis where the bacteria are susceptible. It is particularly effective in treating active TB infections and can also be used to prevent the reactivation of latent TB. Additionally, it may be prescribed for individuals with pulmonary fibrosis, those in close contact with people who have active TB, and those with HIV.

Administration

Isoniazid comes in both tablet and solution forms and should be taken orally without food. The medication is usually taken once a day, but it may also be prescribed to be taken one, two, or three times a week. It is essential to follow the prescribed dosage schedule carefully and not to miss any doses, as stopping the medication too soon can lead to resistant bacteria.

Side Effects

While generally effective, isoniazid can cause some side effects. Common issues include upset stomach and diarrhea when taking the solution form. More severe side effects include eye pain, changes in vision, numbness or tingling in the hands and feet, rash, fever, swollen glands, sore throat, unusual bleeding or bruising, and ongoing pain in the stomach that may spread to the back. If you experience any of these symptoms, it is crucial to consult your doctor immediately.

Important Considerations

Isoniazid may cause liver damage, particularly in patients over 50 years old. It is essential to discuss the benefits and risks of this medication with your doctor. To ensure complete clearance of the TB infection, it is vital to take isoniazid for the full duration of treatment, even if you start feeling better. Stopping the medication too soon can lead to treatment failure and the development of antibiotic-resistant bacteria.

Isoniazid is available only with a doctor’s prescription and comes in tablet and solution forms. If you have any questions or concerns about this medication, it is best to consult with your healthcare provider.