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PDE5 Inhibitor — Erectile Dysfunction

Avanafil

Brand names: Spedra

Avanafil is an oral, rapid-onset phosphodiesterase type-5 (PDE5) inhibitor used on demand for erectile dysfunction. It is valued for its faster onset and short duration relative to some other agents in the class.

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 PDE5, preventing breakdown of cyclic GMP in the corpus cavernosum so that, with sexual stimulation, smooth-muscle relaxation and penile blood flow are enhanced.

Prescribing in practice

  • Absolutely contraindicated with any nitrate or nicorandil because the combination can precipitate profound, life-threatening hypotension.
  • Avoid co-administration with alpha-blockers and other antihypertensives unless the patient is haemodynamically stable, owing to additive blood-pressure lowering.
  • Reduce exposure or avoid with potent CYP3A4 inhibitors and in significant hepatic or renal impairment as detailed in the SPC.

Monitoring

No routine laboratory monitoring is required, but cardiovascular fitness for sexual activity and blood-pressure tolerability should be assessed clinically.

Counselling the patient

  • Take before anticipated sexual activity; effect needs sexual stimulation to work.
  • Seek urgent care for an erection lasting several hours (priapism) or sudden vision or hearing loss.
  • Never combine with nitrate-containing heart medicines or recreational 'poppers'.

Evidence & guidelines

Licensed for erectile dysfunction on the basis of randomised on-demand trials demonstrating improved erectile function scores versus placebo.

Reference: NICE NG44 (Erectile Dysfunction); EAU Sexual Dysfunction Guidelines 2024; 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.