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Isoniazid (Isoniazid) - Summary

 
 



BOXED WARNING


Therefore, patients given isoniazid should be carefully monitored and interviewed at monthly intervals. For persons 35 and older, in addition to monthly symptom reviews, hepatic enzymes (specifically, AST and ALT (formerly SGOT and SGPT, respectively)) should be measured prior to starting isoniazid therapy and periodically throughout treatment. Isoniazid-associated hepatitis usually occurs during the first three months of treatment. Usually, enzyme levels return to normal despite continuance of drug, but in some cases progressive liver dysfunction occurs. Other factors associated with an increased risk of hepatitis include daily use of alcohol, chronic liver disease and injection drug use. A recent report suggests an increased risk of fatal hepatitis associated with isoniazid among women, particularly black and Hispanic women. The risk may also be increased during the post partum period. More careful monitoring should be considered in these groups, possibly including more frequent laboratory monitoring. If abnormalities of liver function exceed three to five times the upper limit of normal, discontinuation of isoniazid should be strongly considered. Liver function tests are not a substitute for a clinical evaluation at monthly intervals or for the prompt assessment of signs or symptoms of adverse reactions occurring between regularly scheduled evaluations. Patients should be instructed to immediately report signs or symptoms consistent with liver damage or other adverse effects. These include any of the following: unexplained anorexia, nausea, vomiting, dark urine, icterus, rash, persistent paresthesias of the hands and feet, persistent fatigue, weakness or fever of greater than 3 days duration and/or abdominal tenderness, especially right upper quadrant discomfort. If these symptoms appear or if signs suggestive of hepatic damage are detected, isoniazid should be discontinued promptly, since continued use of the drug in these cases has been reported to cause a more severe form of liver damage.
Patients with tuberculosis who have hepatitis attributed to isoniazid should be given appropriate treatment with alternative drugs. If isoniazid must be reinstituted, it should be reinstituted only after symptoms and laboratory abnormalities have cleared. The drug should be restarted in very small and gradually increasing doses and should be withdrawn immediately if there is any indication of recurrent liver involvement.
Preventive treatment should be deferred in persons with acute hepatic diseases.

 

ISONIAZID SUMMARY

Isoniazid is an antibacterial available as 100 mg and 300 mg tablets for oral administration.

Isoniazid is recommended for all forms of tuberculosis in which organisms are susceptible. However, active tuberculosis must be treated with multiple concomitant anti-tuberculosis medications to prevent the emergence of drug resistance. Single-drug treatment of active tuberculosis with isoniazid, or any other medication, is inadequate therapy.
Isoniazid is recommended as preventive therapy for the following groups, regardless of age. (Note: the criterion for a positive reaction to a skin test (in millimeters of induration) for each group is given in parenthesis):
     1. Persons with human immunodeficiency virus (HIV) infection (5 mm) and persons with risk factors for HIV infection whose HIV infection status is unknown but who are suspected of having HIV infection. Preventive therapy may be considered for HIV infected persons who are tuberculin-negative but belong to groups in which the prevalence of tuberculosis infection is high. Candidates for preventive therapy who have HIV infection should have a minimum of 12 months of therapy.
     2. Close contacts of persons with newly diagnosed infectious tuberculosis (5 mm). In addition, tuberculin-negative (<5 mm) children and adolescents who have been close contacts of infectious persons within the past 3 months are candidates for preventive therapy until a repeat tuberculin skin test is done 12 weeks after contact with the infectious source. If the repeat skin test is positive (> 5 mm), therapy should be continued.
     3. Recent converters, as indicated by a tuberculin skin test (mm increase for thoseyears of age). All infants and children younger than 4 years of age with a > 10 mm skin test are included in this category.
     4. Persons with abnormal chest radiographs that show fibrotic lesions likely to represent old healed tuberculosis (mm). Candidates for preventive therapy who have fibrotic pulmonary lesions consistent with healed tuberculosis or who have pulmonary silicosis should have 12 months of isoniazid or 4 months of isoniazid and rifampin, concomitantly.
     5. Intravenous drug users known to be HIV-seronegative (>10 mm).
     6. Persons with the following medical conditions that have been reported to increase the risk of tuberculosis (
Additionally, in the absence of any of the above risk factors, persons under the age of 35 with a tuberculin skin test reaction of 10 mm or more are also appropriate candidates for preventive therapy if they are a member of any of the following high-incidence groups:
     1. Foreign-born persons from high-prevalence countries who never received BCG vaccine.
     2. Medically underserved low-income populations, including high-risk racial or ethnic minority populations, especially blacks, Hispanics, and Native Americans.
     3. Residents of facilities for long-term care (e.g., correctional institutions, nursing homes, and mental institutions).
Children who are less than 4 years old are candidates for isoniazid preventive therapy if they have > 10 mm induration from a PPD Mantoux tuberculin skin test.
Finally, persons under the age of 35 who a) have none of the above risk factors (1-6); b) belong to none of the high-incidence groups; and c) have a tuberculin skin test reaction of 15 mm or more, are appropriate candidates for preventive therapy.
The risk of hepatitis must be weighed against the risk of tuberculosis in positive tuberculin reactors over the age of 35. However, the use of isoniazid is recommended for those with the additional risk factors listed above (1-6) and on an individual basis in situations where there is likelihood of serious consequences to contacts who may become infected.


See all Isoniazid indications & dosage >>

NEWS HIGHLIGHTS

Media Articles Related to Isoniazid

Tuberculosis (TB)
Source: MedicineNet Aches, Pain, Fever Specialty [2017.09.20]
Title: Tuberculosis (TB)
Category: Diseases and Conditions
Created: 12/31/1997 12:00:00 AM
Last Editorial Review: 9/20/2017 12:00:00 AM

Tuberculosis Skin Test (PPD Skin Test)
Source: MedicineNet Immunizations Specialty [2017.09.05]
Title: Tuberculosis Skin Test (PPD Skin Test)
Category: Procedures and Tests
Created: 1/13/2004 12:00:00 AM
Last Editorial Review: 9/5/2017 12:00:00 AM

Tuberculosis (TB) Treatment and Vaccine
Source: MedicineNet isoniazid, INH Specialty [2017.04.06]
Title: Tuberculosis (TB) Treatment and Vaccine
Category: Doctor's & Expert's views on Symptoms
Created: 10/30/2014 12:00:00 AM
Last Editorial Review: 4/6/2017 12:00:00 AM

Tuberculosis Diagnosis
Source: MedicineNet Tuberculosis Skin Test (PPD Skin Test) Specialty [2017.03.29]
Title: Tuberculosis Diagnosis
Category: Doctor's & Expert's views on Symptoms
Created: 7/24/2013 12:00:00 AM
Last Editorial Review: 3/29/2017 12:00:00 AM

What Are the Symptoms and Signs of Tuberculosis (TB)?
Source: MedicineNet Tuberculosis Skin Test (PPD Skin Test) Specialty [2017.03.29]
Title: What Are the Symptoms and Signs of Tuberculosis (TB)?
Category: Doctor's & Expert's views on Symptoms
Created: 10/29/2014 12:00:00 AM
Last Editorial Review: 3/29/2017 12:00:00 AM

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Published Studies Related to Isoniazid

The pharmacogenetics of NAT2 enzyme maturation in perinatally HIV exposed infants receiving isoniazid. [2012]
The roles of the NAT2 genotype and enzyme maturation on isoniazid pharmacokinetics were investigated in South African infants with perinatal HIV exposure enrolled in a randomized, double-blind, controlled trial of isoniazid for prevention of tuberculosis disease and latent infection.

Primary isoniazid prophylaxis against tuberculosis in HIV-exposed children. [2011.07.07]
BACKGROUND: The dual epidemic of human immunodeficiency virus (HIV) and tuberculosis is a major cause of sickness and death in sub-Saharan Africa. We conducted a double-blind, randomized, placebo-controlled trial of preexposure isoniazid prophylaxis against tuberculosis in HIV-infected children and uninfected children exposed to HIV during the perinatal period... CONCLUSIONS: Primary isoniazid prophylaxis did not improve tuberculosis-disease-free survival among HIV-infected children or tuberculosis-infection-free survival among HIV-uninfected children immunized with BCG vaccine. Despite access to antiretroviral therapy, the burden of tuberculosis remained high among HIV-infected children. (Funded by the National Institutes of Health and Secure the Future; ClinicalTrials.gov number, NCT00080119.).

The impact of isoniazid preventive therapy and antiretroviral therapy on tuberculosis in children infected with HIV in a high tuberculosis incidence setting. [2011.06]
BACKGROUND: Tuberculosis (TB) is a major cause of morbidity and mortality among children infected with HIV. Strategies to prevent TB in children include isoniazid preventive therapy (IPT) and antiretroviral therapy (ART). IPT and ART have been reported to reduce TB incidence in adults but there are few studies in children. OBJECTIVE: To investigate the combined effect of IPT and ART on TB risk in children infected with HIV... CONCLUSIONS: The finding that IPT may offer additional protection in children on ART has significant public health implications because this offers a possible strategy for reducing TB in children infected with HIV. Widespread use of this strategy will however require screening of children for active TB disease. Trial registration Trial registration-Clinical Trials NCT00330304.

The Pharmacogenetics of NAT2 Enzyme Maturation in Perinatally HIV Exposed Infants Receiving Isoniazid. [2011.05.10]
The roles of the NAT2 genotype and enzyme maturation on isoniazid pharmacokinetics were investigated in South African infants with perinatal HIV exposure enrolled in a randomized, double-blind, controlled trial of isoniazid for prevention of tuberculosis disease and latent infection.

6-month versus 36-month isoniazid preventive treatment for tuberculosis in adults with HIV infection in Botswana: a randomised, double-blind, placebo-controlled trial. [2011.05.07]
BACKGROUND: In accordance with WHO guidelines, people with HIV infection in Botswana receive daily isoniazid preventive therapy against tuberculosis without obtaining a tuberculin skin test, but duration of prophylaxis is restricted to 6 months. We aimed to assess effectiveness of extended isoniazid therapy... INTERPRETATION: In a tuberculosis-endemic setting, 36 months' isoniazid prophylaxis was more effective for prevention of tuberculosis than was 6-month prophylaxis in individuals with HIV infection, and chiefly benefited those who were tuberculin skin test positive. FUNDING: US Centers for Disease Control and Prevention and US Agency for International Development. Copyright (c) 2011 Elsevier Ltd. All rights reserved.

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Clinical Trials Related to Isoniazid

Three Months of Weekly Rifapentine and Isoniazid for M. Tuberculosis Infection [Completed]
Open-label, multi-center, Phase III clinical trial to compare the effectiveness and tolerability of a three-month (12-dose) regimen of weekly rifapentine and isoniazid (3RPT/INH) to the effectiveness of a nine-month (270-dose)regimen of daily isoniazid (9INH) to prevent tuberculosis (TB) among high-risk tuberculin skin-test reactors, including children and HIV-infected persons, who require treatment of latent TB infection (LTBI).

Study of Limited Versus Continuous Isoniazid Tuberculosis Preventive Therapy in HIV-infected Persons in Botswana [Completed]
This is a randomized, blinded, two-arm comparative trial of continued versus limited isoniazid (INH) tuberculosis (TB) preventive therapy in HIV-infected adults in Gaborone and Francistown, Botswana. Subjects will be accrued over two years and followed for a minimum of 36 months.

Isoniazid Dose Adjustment According to NAT2 Genotype (IDANAT2) [Terminated]
The study is conducted to compare safety and efficacy of isoniazid administered as an adjusted dose based on NAT2 (arylamine N-acetyltransferase type 2)genotype and as a standard dose. The hypothesis is that the genotype-adjusted dose is superior to the standard dose with regard to hepatotoxicity and early treatment failure, respectively, in the group of slow and rapid acetylators of NAT2.

TBTC Study 28: Moxifloxacin Versus Isoniazid for TB Treatment [Completed]
This double-blind, randomized controlled trial evaluates moxifloxacin versus isoniazid in daily treatment during the first two months of treatment with rifampin, pyrazinamide and ethambutol for sputum smear-positive pulmonary tuberculosis.

A Trial of Isoniazid for the Reversion of Interferon Gamma ELISPOT in Tuberculosis (TB) Case Contacts [Completed]
There are new TB vaccines already developed that need to be tried in humans to assess their efficacy. The researchers had previously shown that production of interferon gamma by T cells in response to TB antigens is a more specific marker of TB infection. The researchers hypothesize that this can be used as a reliable early marker of TB vaccine efficacy. The researchers expect to show a significantly increased reversion of this test in household contacts of TB patients given Isoniazid prophylaxis treatment for 6 months.

more trials >>

Reports of Suspected Isoniazid Side Effects

Hepatic Function Abnormal (30)Pyrexia (28)Acute Hepatic Failure (26)Liver Disorder (20)Alanine Aminotransferase Increased (18)Hepatitis (17)Jaundice (16)Aspartate Aminotransferase Increased (15)Drug Rash With Eosinophilia and Systemic Symptoms (13)Cough (12)more >>


PATIENT REVIEWS / RATINGS / COMMENTS

Based on a total of 1 ratings/reviews, Isoniazid has an overall score of 7. The effectiveness score is 10 and the side effect score is 10. The scores are on ten point scale: 10 - best, 1 - worst.
 

Isoniazid review by 28 year old female patient

  Rating
Overall rating:  
Effectiveness:   Highly Effective
Side effects:   No Side Effects
  
Treatment Info
Condition / reason:   Tuberculosis
Dosage & duration:   150 mg taken 1/day for the period of 6 months
Other conditions:   none
Other drugs taken:   None
  
Reported Results
Benefits:   While I did not have active Tuberculosis, I had tested positive. Taking Isoniazid will prevent a future case of Tuberculosis from developing.
Side effects:   None, although liver screenings were required, and I could not drink alcohol. I also was encouraged to take B12 supplements.
Comments:   After testing positive for Tuberculosis, my Dr. prescribed a 6 month course of Isoniazid.

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Page last updated: 2017-09-20

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