ClinCalc Pro
Menu
Calculators Drugs Pathways AI Dx Donate Get the App
Pulmonary Arterial Hypertension Pregnancy: Contraindicated — teratogenic in animal studies; PPP mandatory with two reliable contraceptive methods and monthly pregnancy testing

Macitentan

Brand names: Opsumit

Adult dose

Dose: 10 mg once daily
Route: Oral
Frequency: Once daily
Max: 10 mg/day
Dual endothelin receptor antagonist (ETA/ETB). SERAPHIN trial showed 45% relative risk reduction in morbidity/mortality composite endpoint. High lipophilicity — prolonged receptor occupancy.

Paediatric dose

Route: Oral
Seek specialist opinion — not licensed in children

Dose adjustments

Renal

No dose adjustment required

Hepatic

Avoid in severe hepatic impairment; use with caution in moderate impairment

Clinical pearls

  • SERAPHIN trial (Pulido et al. NEJM 2013): landmark event-driven morbidity/mortality trial — first ERA with proven composite endpoint benefit; 742 patients, 38-month follow-up
  • Unlike bosentan: monthly LFT monitoring NOT required — LFT at baseline only then if symptomatic. This simplifies long-term management vs bosentan.
  • High tissue penetration due to lipophilicity — prolonged receptor occupancy may explain sustained benefit
  • Pregnancy prevention programme mandatory — two reliable contraceptive methods; monthly pregnancy tests
  • Anaemia: check Hb at baseline, 1 month, 3 months — Hb <8 g/dL: consider stopping

Contraindications

  • Pregnancy (teratogenic — PPP mandatory)
  • Severe hepatic impairment
  • Hypersensitivity

Side effects

  • Anaemia (Hb drop in 13% — more common than bosentan)
  • Nasopharyngitis
  • Headache
  • Flushing
  • Urinary tract infection
  • Fluid retention

Interactions

  • Strong CYP3A4 inducers (rifampicin, carbamazepine) — reduce macitentan levels; avoid
  • Strong CYP3A4 inhibitors (ketoconazole, ritonavir) — increase levels; use with caution
  • Cyclosporin — increases exposure

Monitoring

  • Haemoglobin baseline, 1 month, 3 months
  • LFT baseline
  • Pregnancy tests monthly
  • 6-minute walk distance
  • Echocardiography

Reference: BNFc; BNF 90; SERAPHIN Trial (Pulido et al. NEJM 2013); NICE TA459; SPC Opsumit. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

Calculators
Drugs
Pathways