Isoniazid Preventive Therapy for Tuberculosis: Decision Analysis Considering Ethnicity and Gender

Abstract

The decision to prescribe or withhold isoniazid (INH) preventive therapy for low-risk tuberculin reactors has been highly controversial, primarily due to isoniazid's possible hepatotoxic effects. Previous analyses have explored the INH decision only from the perspective of patient age, recognizing that the risks of INH-induced hepatotoxicity are age related. Decision analyses presented in this paper assess the impact of gender and ethnic group, as well as age, on the INH decision. Results for low-risk patients favor prescribing INH preventive therapy for all 20-yr-olds, all 35-yr-olds except black women, and no 50-yr-olds, projecting life expectancy benefits that range from 3 to 19 days. A comparison set of analyses performed for high-risk patients favors prescribing INH for all groups except 50-yr-old black women. These findings suggest that ethnicity, gender, and age should be considered when making the decision to prescribe or withhold INH preventive therapy.

Hepatotoxicity Associated With Isoniazid Preventive Therapy

“…ORE THAN 30YEARSAFTERITS introduction, 1 isoniazidpreventivetherapyforlatenttuberculosis (TB) infection is still a subject of debate, mainly because of continuingconcernsabouthepatotoxicity. [2][3][4][5] There are, however, good reasons to reconsider the hepatotoxicity of isoniazid at this time, with the anticipation that the risk is less than believed. The base of evidence for isoniazid hepatotoxicity, including a level of risk in the range of 5 to 20 cases of hepatotoxicity expected per 1000 persons receiving treatment with a 1% to 10% casefatality rate, is composed of studies done more than 20 years ago.…”

Treatment of Latent Tuberculosis Infection in Patients Aged ≥35 Years

“…A complete medical history was obtained from each patient by a nurse, including a symptom review and detailed questions about drug allergies, current medications, and use of alcohol. Alcohol use was defined as consuming 13 alcoholic beverages daily; a standardized instrument designed for the measurement of alcohol consumption was not used. A chest radiograph was done, and baseline alanine aminotransferase (ALT) levels were determined.…”

“…Others have shown that older women are less likely to complete preventive therapy [11,12], and this has been linked to the occurrence of elevated results of liver function tests [11][12][13][14]. None of these studies mentions whether the women were taking concomitant medications.…”

A review of isoniazid‐related hepatotoxicity during chemoprophylaxis

“…Some studies that used the USPHS rates concluded that the risks of isoniazid generally outweighed the potential benefitsJz5 while others favour its use in those under 35 years of age. 26 Due to the wide range of mortality rates found in many studies,'"~'.' an average fatality rate of 0.0 1 % has been used by some who find isoniazid to be beneficial for reactive patients of all If the additional benefit of preventing secondary spread of T B to others is taken into account, the argument for prescribing isoniazid prophylactic therapy is increased further.?…”