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PDE5 Inhibitor — Pulmonary Arterial Hypertension / Raynaud's Phenomenon

Sildenafil

Brand names: Revatio (PAH), Viagra (ED)

In the vascular setting sildenafil is used as a pulmonary vasodilator for pulmonary arterial hypertension (under the brand Revatio), distinct from its erectile dysfunction indication.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

Clinical monograph

How it works

It selectively inhibits phosphodiesterase type 5, preventing breakdown of cyclic GMP in vascular smooth muscle and so enhancing nitric-oxide-mediated pulmonary vasodilatation.

Prescribing in practice

  • It is absolutely contraindicated with nitrates and nitric oxide donors because of life-threatening hypotension, and should not be combined with riociguat for the same reason.
  • Avoid co-administration with potent CYP3A4 inhibitors without dose review, and use cautiously in patients on alpha-blockers or with resting hypotension.
  • Caution is needed in left ventricular outflow obstruction and in conditions predisposing to priapism, and it should not be used purely to improve outcome in pulmonary hypertension associated with sickle cell disease.

Monitoring

Monitor blood pressure, symptomatic response and exercise capacity, and review vision and hearing if sudden disturbances are reported.

Counselling the patient

  • Never take with nitrate heart medicines or recreational nitrates ('poppers').
  • Report sudden loss of vision or hearing, or a painful prolonged erection.
  • Headache, flushing and indigestion are common and usually settle.

Evidence & guidelines

Its pulmonary arterial hypertension licence is supported by the SUPER-1 trial and reflected in the SPC and specialist guidance.

Reference: SUPER-1 Trial; STARTS-2 Trial; NICE TA235 (Sildenafil for PAH); ESC/ERS PAH Guidelines 2022; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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