PRIFTIN 150MG FILM COATED TABLETS

Indications

• Latent tuberculosis infection
• Active tuberculosis (as part of combination therapy)

Dosage

Children: Refer to the BNF for Children for appropriate pediatric dosing information.

Adults: Refer to specific guidelines or the BNF for precise dosing recommendations.

Mechanism of action

Rifapentine exerts its antibacterial effect by binding to the beta subunit of bacterial DNA-dependent RNA polymerase, thereby inhibiting RNA synthesis in susceptible bacteria. This action leads to the disruption of protein synthesis, ultimately resulting in bacterial cell death.

Pharmacodynamics

The pharmacodynamic profile of rifapentine includes its bactericidal activity against Mycobacterium tuberculosis. Its unique pharmacokinetic properties allow it to maintain effective drug levels in the body, reducing the frequency of dosing while still effectively targeting the bacteria. Rifapentine is particularly potent during the early and active phases of TB infection, making it a crucial component of TB treatment regimens.

Pharmacokinetics

Rifapentine has a high oral bioavailability and is well absorbed from the gastrointestinal tract. It undergoes extensive hepatic metabolism, primarily by cytochrome P450 enzymes, which can be affected by other medications that induce or inhibit these enzymes. The drug has a long elimination half-life, typically ranging from 12 to 16 hours, allowing for once or twice weekly dosing. Its metabolites are excreted mainly in the feces, with a smaller amount excreted in the urine.

Contra-indications

• Hypersensitivity to rifapentine or any component of the formulation
• Active liver disease or significant hepatic impairment
• Concurrent use with certain medications that may cause severe liver injury

Adverse effects

• Gastrointestinal disturbances including nausea and vomiting
• Hepatotoxicity, which may manifest as elevated liver enzymes
• Rash or other hypersensitivity reactions
• Flu-like symptoms
• Potential for discoloration of body fluids, such as urine and tears

Interactions

• May interact with oral contraceptives, reducing their effectiveness
• Potential interactions with anticoagulants, leading to altered anticoagulant effects
• Induction of cytochrome P450 enzymes may lead to reduced effectiveness of other drugs metabolized by this pathway
• Concurrent use with other antituberculosis agents may alter their pharmacokinetics

Precautions

• Monitor liver function tests prior to and during treatment
• Use with caution in patients with a history of liver disease
• Assess for potential drug interactions, particularly with drugs metabolized by the liver
• Monitor for signs of hypersensitivity or severe adverse reactions

Pregnancy

Rifapentine is generally not recommended during pregnancy due to limited safety data. It should only be used if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

Rifapentine is excreted in breast milk. Caution should be exercised when administering to nursing mothers, and the risks and benefits should be considered.

Storage

Store at room temperature, away from moisture and heat. Keep out of reach of children.

Formulations

• Rifapentine 150 mg tablets
• Rifapentine 300 mg tablets