What is 3HP?
3HP is a short-course TB preventive therapy regimen that combines two TB drugs—isoniazid and rifapentine—weekly for three months. The World Health Organization (WHO) recently released consolidated guidelines for the treatment of latent TB infection that recommends the use of 3HP for people living with HIV and contacts of TB cases of any age.
- Components: 900mg Isoniazid (H) + 900mg Rifapentine (P), separate tablets
- Dosage: Once weekly
- Duration: 12 Weeks
- Target Populations: People living with HIV and household contacts over 2 years, regardless of HIV status
The advantages of 3HP
- The 12-dose regimen reduces treatment time to 3 months, compared to al least 6 months for isoniazid
- It requires weekly doses compared to daily doses with isoniazid
- Shorter treatment regimens have been shown to have higher completion rates
- There are lower rates of hepatotoxicity with 3HP than with daily doses of isoniazid
- It places less of a burden on TB and HIV programs compared to at least 6 months of isoniazid
- Modelling studies indicate that 3HP is cost-effective, reducing the economic burden of TB control efforts.
Who is not recommended for treatment with 3HP?
- Children under 2 years of age, as proper dosage are not yet known
- Patients taking certain drugs that interact with 3HP such as protease inhibitors for HIV
- Persons presumed infected with M. tuberculosis that is resistant to isoniazid and/or rifampin
- Until the results of ongoing studies evaluating the safety of 3HP in pregnant women are available, caution should be exercised in using 3HP for pregnant women
- Women who are unwilling or unable to use contraception. As 3HP decreases hormonal contraceptive levels, women must be advised to use barrier methods such as condoms or diaphragms
- Patients who had prior adverse events or hypersensitivity to isoniazid or rifampin or rifapentine.