rilpivirine: clinical use

Prescribing considerations

• Confirm virological suppression, treatment history, absence of relevant NNRTI or integrase-inhibitor resistance, and no previous virological failure with these classes.
• Assess ability and willingness to attend injection visits and establish a contingency plan for interruptions.
• Consider archived rilpivirine resistance, HIV-1 subtype A6/A1 and raised BMI when evaluating virological-failure risk.
• Do not initiate in hepatitis B co-infection; ensure appropriate hepatitis B treatment.
• Account for the prolonged pharmacokinetic tail when stopping, changing interacting medicines or planning pregnancy.

Contraindications and cautions

• Hypersensitivity to rilpivirine or an excipient.
• Concomitant carbamazepine, oxcarbazepine, phenobarbital or phenytoin.
• Concomitant rifabutin, rifampicin or rifapentine.
• Systemic dexamethasone except as a single-dose treatment.
• St John's wort.
• Not recommended in severe hepatic impairment; use caution with moderate hepatic impairment.

Monitoring

• HIV viral load, attendance and evidence of virological rebound or resistance.
• Observe briefly after injection for an acute post-injection reaction.
• Liver function where clinically indicated, particularly with hepatitis C co-infection or hepatotoxicity symptoms.
• Pregnancy requires specialist reassessment and close viral-load monitoring.
• Review QT-risk medicines and consider ECG assessment when clinically indicated.

Clinical pharmacology

Rilpivirine is a diarylpyrimidine NNRTI that non-competitively inhibits HIV-1 reverse transcriptase. The intramuscular suspension is slowly absorbed from the gluteal depot; metabolism is mainly through CYP3A and protein binding is extensive.

Formulation and product differences

• The selected product is a prolonged-release intramuscular suspension administered only by a healthcare professional.
• It must be used with injectable cabotegravir at a separate gluteal site.
• Treatment may begin directly with injections or after an oral tolerability lead-in.
• Oral rilpivirine requires food and has acid-suppression interactions that do not arise from gastric absorption of the injection.
• Residual rilpivirine may remain measurable for years after the final injection.

Injection

Route: Parenteral

Strengths: 900 mg