#1 Clinical Trials Search in Europe

Isoniazid

Isoniazid is a crucial antibiotic used in the prevention and treatment of tuberculosis (TB). This article examines various clinical trials investigating the effectiveness, safety, and optimal dosing of isoniazid in different populations, including HIV-positive individuals, kidney transplant recipients, and those with latent TB infection. These studies aim to improve TB prevention strategies and treatment outcomes while minimizing side effects.

Table of Contents

What is Isoniazid?

Isoniazid, also known as INH or by its chemical name Isonicotinic Acid Hydrazide, is an important medication used primarily in the treatment and prevention of tuberculosis (TB)[1]. It is one of the first-line drugs used to combat TB, a serious bacterial infection that mainly affects the lungs but can also impact other parts of the body[2].

Uses of Isoniazid

Isoniazid is used in several ways to manage tuberculosis:

  • Active TB Treatment: It is used as part of a combination therapy to treat active tuberculosis infections[1].
  • Latent TB Prevention: Isoniazid is also used to prevent the development of active TB in people who have latent (dormant) TB infections[3].
  • TB Prevention in High-Risk Groups: It may be given to people at high risk of developing TB, such as those with HIV or those who have been in close contact with TB patients[4].

How Isoniazid Works

Isoniazid works by killing the bacteria that cause tuberculosis. It does this by interfering with the bacteria’s ability to make certain substances they need to survive. Specifically, it inhibits the production of mycolic acids, which are essential components of the bacterial cell wall[3].

Dosage and Administration

The dosage and duration of isoniazid treatment can vary depending on the specific situation:

  • Standard Dosage: For adults, a common dose is 300 mg daily[1].
  • Weight-Based Dosing: In some cases, dosing may be adjusted based on body weight, typically around 5 mg per kilogram of body weight[4].
  • Duration: Treatment duration can range from 6 months for latent TB prevention to longer periods for active TB treatment, often as part of a combination therapy[5].

Effectiveness of Isoniazid

Isoniazid has been shown to be highly effective in both treating active TB and preventing the development of active TB in people with latent infections. Studies have demonstrated its ability to significantly reduce the risk of TB in high-risk populations, such as HIV-positive individuals[4].

Side Effects and Safety

While isoniazid is generally well-tolerated, it can cause side effects in some people:

  • Liver Problems: The most serious potential side effect is liver damage. Regular monitoring of liver function may be necessary during treatment[2].
  • Nerve Issues: Isoniazid can sometimes cause nerve problems (peripheral neuropathy). This risk can be reduced by taking vitamin B6 (pyridoxine) along with isoniazid[6].
  • Other Side Effects: Less common side effects may include skin rashes, fever, and changes in blood cell counts[7].

Special Considerations

There are several important factors to consider when using isoniazid:

  • Genetic Factors: Some people may metabolize isoniazid differently due to genetic variations. This can affect both the drug’s effectiveness and the risk of side effects[8].
  • Alcohol Use: Drinking alcohol while taking isoniazid can increase the risk of liver damage[2].
  • Pregnancy and Breastfeeding: Isoniazid can be used during pregnancy and breastfeeding, but close monitoring is necessary[7].

Ongoing Research

Researchers continue to study isoniazid to improve its use and effectiveness:

  • Personalized Dosing: Studies are exploring how to adjust isoniazid dosing based on a person’s genetic makeup to maximize effectiveness and minimize side effects[8].
  • Combination Therapies: Research is ongoing into the best ways to combine isoniazid with other TB medications for optimal treatment outcomes[4].
  • Prevention Strategies: Studies are investigating the use of isoniazid in preventing TB in specific high-risk groups, such as HIV-exposed infants[7].
Aspect Details
Primary Uses Prevention and treatment of tuberculosis (TB), including latent TB infection
Study Populations HIV-positive individuals, kidney transplant recipients, household contacts of TB patients, high-risk populations in TB-endemic areas
Dosing Strategies Standard dosing (e.g., 300 mg daily), weight-based dosing, genotype-adjusted dosing (based on NAT2 status)
Treatment Durations Ranging from 3-6 months to 36 months, depending on the study and population
Key Outcomes Measured TB incidence, treatment completion rates, adverse events (especially liver toxicity), bioequivalence of different formulations
Combination Therapies Often studied with other TB drugs like rifapentine, or with pyridoxine to prevent side effects
Safety Considerations Monitoring for drug-induced liver injury, neurotoxicity, and other adverse events
Novel Approaches Personalized dosing based on genetic factors, periodic vs. continuous treatment regimens

FAQ

  • What is isoniazid used for in clinical trials? Isoniazid is primarily used in clinical trials for the prevention and treatment of tuberculosis (TB). It is studied in various contexts, including latent TB infection, active TB treatment, and TB prevention in high-risk populations such as HIV-positive individuals and organ transplant recipients.
  • How long does isoniazid treatment typically last in these trials? The duration of isoniazid treatment varies across trials. Some studies investigate short-term regimens of 3-6 months, while others explore longer durations of up to 36 months. For example, one trial compared 6 months of daily isoniazid to 36 months of continuous treatment in HIV-infected adults.
  • Are there any side effects associated with isoniazid use in clinical trials? Yes, some trials specifically monitor for side effects of isoniazid. The most common concern is drug-induced liver injury. Some studies adjust dosing based on genetic factors (NAT2 polymorphism) to reduce the risk of liver toxicity. Other potential side effects include neurotoxicity, which is sometimes prevented by administering pyridoxine (vitamin B6) alongside isoniazid.
  • How is isoniazid dosing determined in these clinical trials? Isoniazid dosing in clinical trials is determined through various methods. Some studies use standard dosing (e.g., 300 mg daily), while others explore personalized dosing based on factors such as body weight or genetic markers. For instance, one trial adjusted doses according to NAT2 genotype, which affects how quickly individuals metabolize the drug.
  • What populations are being studied in isoniazid clinical trials? Isoniazid clinical trials involve diverse populations, including HIV-positive individuals, kidney transplant recipients, individuals with latent TB infection, and those at high risk of TB exposure. Some studies focus on specific groups like household contacts of TB patients or people living in high TB burden countries.

Ongoing Clinical Trials on Isoniazid

  • Study evaluating blood biomarkers for diagnosis and monitoring treatment in patients with pulmonary tuberculosis using isoniazid, rifampicin, pyrazinamide, and ethambutol combination

    Recruiting

    1 1 1 1
    Investigated diseases:
    Investigated drugs:
    Spain

  • Study on High-Dose Rifampicin Safety for Adults with Complex Tuberculosis Using Isoniazid, Pyrazinamide, and Ethambutol Combination

    Recruiting

    1 1 1
    Investigated drugs:
    The Netherlands Spain

  • Study on the Effects of Tedizolid and Linezolid for Patients with Suspected Lung Tuberculosis

    Recruiting

    1 1 1
    Investigated drugs:
    France

  • Study Comparing Adalimumab and Mycophenolate Mofetil for Patients with Steroid-Dependent Non-Infectious Uveitis

    Recruiting

    1 1 1 1
    Investigated diseases:
    Investigated drugs:
    France

  • Study on the Effectiveness and Safety of High-Dose Rifampicin, Moxifloxacin, and Linezolid for Patients with Pulmonary Tuberculosis

    Not recruiting

    1 1 1
    Investigated diseases:
    Investigated drugs:
    Spain

  • Study Comparing Rifampicin, Isoniazid, and Rifapentine Regimens for Treating Latent Tuberculosis in Patients with End-Stage Kidney Disease

    Not recruiting

    1 1 1 1
    Investigated diseases:
    Investigated drugs:
    Spain

Glossary

  • Isoniazid: An antibiotic medication used primarily for the prevention and treatment of tuberculosis. It works by inhibiting the synthesis of mycolic acid, a component of the cell wall in Mycobacterium tuberculosis.
  • Tuberculosis (TB): An infectious disease caused by the bacterium Mycobacterium tuberculosis, primarily affecting the lungs but can also impact other parts of the body.
  • Latent TB Infection (LTBI): A condition in which a person is infected with Mycobacterium tuberculosis but does not have active tuberculosis disease and is not contagious.
  • NAT2 Genotype: A genetic variation that affects how quickly an individual metabolizes certain drugs, including isoniazid. It can influence the effectiveness and potential side effects of the medication.
  • Bioequivalence: The absence of a significant difference in the rate and extent at which the active ingredient in pharmaceutical equivalents becomes available at the site of drug action when administered at the same dose under similar conditions.
  • Pharmacovigilance: The science and activities relating to the detection, assessment, understanding, and prevention of adverse effects or any other drug-related problems.
  • Interferon Gamma Release Assay (IGRA): A blood test used to detect Mycobacterium tuberculosis infection by measuring the immune system's response to TB antigens.
  • Tuberculin Skin Test (TST): A method used to determine if someone has been infected with Mycobacterium tuberculosis by injecting a small amount of fluid (called tuberculin) into the skin on the lower part of the arm.
  • Drug-Induced Liver Injury: Liver damage caused by medication or other chemical substances, which can be a potential side effect of isoniazid treatment.
  • Pyridoxine: Also known as vitamin B6, it is often given alongside isoniazid to prevent neurotoxicity, a potential side effect of the medication.

References

  1. https://clinicaltrials.gov/study/NCT02043314
  2. https://clinicaltrials.gov/study/NCT03665402
  3. https://clinicaltrials.gov/study/NCT00293228
  4. https://clinicaltrials.gov/study/NCT02980016
  5. https://clinicaltrials.gov/study/NCT00164281
  6. https://clinicaltrials.gov/study/NCT06512831
  7. https://clinicaltrials.gov/study/NCT02613169
  8. https://clinicaltrials.gov/study/NCT00571753