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PDE5 Inhibitor — Erectile Dysfunction Pregnancy: Not applicable — male indication

Avanafil

Brand names: Spedra

Adult dose

Dose: 100-200 mg taken 15-30 minutes before sexual activity
Route: Oral
Frequency: As needed (maximum once daily)
Max: 200 mg per dose
Fastest onset of all PDE5 inhibitors — as little as 15 minutes. Start at 100 mg; reduce to 50 mg if poorly tolerated; increase to 200 mg if needed

Paediatric dose

Dose: Not applicable N/A/kg
Route: Oral
Frequency: Not applicable
Max: Not applicable
Not applicable

Dose adjustments

Renal

No dose adjustment required for mild-moderate impairment; use with caution in severe renal impairment

Hepatic

No dose adjustment for mild impairment; avoid in severe hepatic impairment

Paediatric weight-based calculator

Not applicable

Clinical pearls

  • Fastest onset of PDE5 inhibitors — clinically relevant advantage for spontaneity; useful when sildenafil or vardenafil onset of 30-60 min is inconvenient
  • Higher PDE5 selectivity than sildenafil — fewer off-target effects on PDE6 (retinal) and PDE11 (testicular); fewer visual disturbances and back pain
  • No QT prolongation signal unlike vardenafil — preferred in patients with cardiac conduction concerns
  • Same nitrate contraindication applies as all PDE5 inhibitors — never co-prescribe with any nitrate formulation
  • NICE recommends at least one PDE5 inhibitor on NHS prescription for ED — patient preference between agents should guide choice after discussing onset and duration

Contraindications

  • Concurrent nitrates (absolute)
  • Concurrent guanylate cyclase stimulators (riociguat)
  • Severe cardiovascular disease
  • Uncontrolled hypotension

Side effects

  • Headache
  • Flushing
  • Nasal congestion
  • Back pain
  • Hypotension
  • Visual disturbances (less than sildenafil)

Interactions

  • Nitrates (absolute contraindication)
  • Alpha-blockers (additive hypotension — 2-hour gap recommended)
  • Strong CYP3A4 inhibitors (ketoconazole, ritonavir — max 50 mg dose)
  • Moderate CYP3A4 inhibitors (fluconazole, diltiazem — max 100 mg dose)

Monitoring

  • Cardiovascular assessment
  • Blood pressure
  • Treatment response

Reference: BNFc; BNF 90; NICE NG44 (Erectile Dysfunction); EAU Sexual Dysfunction Guidelines 2024. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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