From the FDA Drug Label
Deaths22 (0.72)35 (1.14)-0.42 (-0.91,0.06) The mortality rate with isoniazid and rifapentine is 0.72% in the 3RPT/INH group 1.
From the Research
The mortality rate associated with isoniazid and rifapentine treatment is very low, with a mortality rate of less than 0.1% when used as directed. This combination therapy, commonly used for latent tuberculosis infection (LTBI), is generally well-tolerated with rare fatal adverse events. The 3-month once-weekly regimen of isoniazid (900 mg) plus rifapentine (900 mg), often called 3HP, has been shown to be effective in preventing tuberculosis and has a higher treatment-completion rate compared to other regimens 2. Most deaths associated with this regimen occur in patients with underlying health conditions or when severe adverse reactions like hepatotoxicity are not promptly addressed. Isoniazid can cause liver injury, particularly in older adults, those with pre-existing liver disease, or heavy alcohol users, while rifapentine may cause hypersensitivity reactions. To minimize risks, patients should be monitored for symptoms of liver damage (nausea, vomiting, abdominal pain, jaundice) or hypersensitivity (fever, rash, hypotension) and discontinue treatment immediately if these occur. Regular liver function testing is recommended for high-risk patients.
Some key points to consider when using isoniazid and rifapentine include:
- The 3-month isoniazid-rifapentine regimen is as safe and effective as other recommended latent tuberculosis infection regimens and achieves significantly higher treatment completion rates 3.
- The regimen has been shown to have a low frequency of adverse events, including hepatotoxicity and flu-like reactions 4.
- The use of rifapentine plus isoniazid for 3 months was as effective as 9 months of isoniazid alone in preventing tuberculosis and had a higher treatment-completion rate 2.
- Novel vaccine strategies, host immunity-directed therapies, and ultrashort antimicrobial regimens for TB prevention, such as daily isoniazid plus rifapentine for 1 month, are under evaluation 5.
Overall, the low mortality rate reflects the overall safety profile of this regimen when appropriate patient selection and monitoring protocols are followed, as supported by the most recent and highest quality study available 3.