Avanafil: the fastest-onset PDE5 inhibitor

Sildenafil, tadalafil, vardenafil and avanafil are the four oral phosphodiesterase type 5 inhibitors approved for erectile dysfunction in the US and Europe, and they are not interchangeable in the evidence. Avanafil’s whole identity is speed: it is absorbed faster than the others and is approved for use 15 to 30 minutes before sexual activity. The question this page asks is the less comfortable one, which is whether being faster also makes it weaker, and what the comparative trials actually print.

The pharmacokinetics are the product

The 2013 Drugs Aging review of avanafil records a median time to maximum plasma concentration of 30 to 45 minutes after oral administration. In the pivotal 12-week randomised double-blind placebo-controlled multicentre trial, the 50, 100 and 200 mg arms all improved the IIEF erectile function domain and both co-primary endpoints of successful vaginal penetration and successful intercourse significantly more than placebo, and the treatment effect in the 100 and 200 mg arms was significantly larger than in the 50 mg arm.

The fastest window is the part that gets quoted, so here is the exact framing from the same abstract: for avanafil recipients, approximately two-thirds of intercourse attempts made prior to 15 minutes, or more than six hours, after administration were successful, compared with approximately one-quarter of those attempts on placebo. That is a within-trial comparison against placebo, not against another PDE5 inhibitor.

A dedicated dose-escalation pharmacokinetic study in healthy Korean male volunteers backs the curve. Thirty of 32 subjects completed it. Avanafil reached mean Tmax at 0.33 to 0.52 hours after dosing, with a mean apparent half-life of 5.36 to 10.66 hours, and both AUC and Cmax were proportional to dose across the 50, 100 and 200 mg arms over seven days. There were no clinically relevant changes in vital signs, ECG, physical examination or colour discrimination testing, and all adverse events resolved spontaneously.

It was developed with on-demand dosing that may be taken after food and/or alcohol, which is the practical difference from sildenafil’s absorption rules.

What the pooled placebo comparisons show

A 2019 systematic review and meta-analysis pooled eight randomised trials with 3,709 patients. Against placebo, avanafil raised successful vaginal penetration (RR 3.20, 95% CI 2.60 to 3.95), successful intercourse (RR 2.53, 95% CI 2.19 to 2.92) and the IIEF-EF score (MD 4.57, 95% CI 3.68 to 5.46), and also raised treatment-emergent adverse events (RR 1.78, 95% CI 1.38 to 2.31). Within that pool, 200 mg beat 100 mg on successful intercourse and on the IIEF-EF score, but not on penetration or on adverse events.

A separate 2023 meta-analysis across 11 publications reported the same shape: IIEF-EF MD 4.39 (95% CI 3.41 to 5.37), SEP-2 RR 3.43, SEP-3 RR 2.30, treatment-emergent adverse events RR 1.49 (95% CI 1.12 to 1.96). The 2014 dose-comparison meta-analysis put the IIEF-EF gain at MD 4.47 (95% CI 3.51 to 5.43) and put the tolerability cost precisely: against placebo, any adverse event RR 2.56, flushing RR 6.06 (95% CI 3.37 to 10.88) and headache RR 7.54 (95% CI 3.52 to 16.12).

The 2014 review that pooled four trials and 1,381 patients is the most direct statement of the mechanism-specific effect: at 100 mg, successful vaginal penetration OR 5.06 (95% CI 3.29 to 7.78) and successful intercourse OR 3.99 (95% CI 2.80 to 5.67). It also notes that the 200 mg arm carries more headaches than the 100 mg arm.

Where avanafil ranks against the others

This is the part that usually gets left out of a product page. The most recent dose-specific network meta-analysis, covering 83 double-blind placebo-controlled randomised trials and 6,029 participants, ranked the on-demand agents for achieving a satisfactory erectile function score (IIEF domain above 26). Sildenafil 100 mg came first at OR 9.06, sildenafil 50 mg at 7.90, vardenafil 10 mg at 7.78, tadalafil 20 mg at 7.13, tadalafil 10 mg at 3.14 — and then avanafil 200 mg at 3.42 and avanafil 100 mg at 1.75. A threshold analysis testing whether moderate study differences could flip those rankings found a statistically significant improvement only for sildenafil at 100 mg (OR 2.20, 95% CI 1.78 to 2.63) and 50 mg (OR 2.10, 95% CI 1.69 to 2.50).

On treatment-related adverse events, the same analysis ranked odds highest for vardenafil, then avanafil, then sildenafil, and lowest for tadalafil.

The 2021 overview of systematic reviews, which is about as large as this literature gets at 23 studies, 154,796 participants and 258 meta-analytic effects, reached the same conclusion in more cautious words: sildenafil at 50 or 100 mg was considered the most effective compound in the general population, and the existing evidence comparing different PDE5 inhibitors is low. Its own note is that most of that comparison comes from indirect comparisons rather than head-to-head trials.

The head-to-head trial, and its size

There is one randomised double-blind active-controlled comparison, and it is small. In the 2022 multicentre trial, 220 men were randomised 1:1 to avanafil 100 mg or sildenafil 50 mg, with escalation to 200 mg or 100 mg allowed. Escalation was required by 40.0% of the avanafil group and 45.6% of the sildenafil group. The mean IIEF-EF difference in change from baseline grew from 1.1 points at week 4 (95% CI −0.2 to 2.5) to 2.1 points at week 12 (95% CI 0.8 to 3.5), which the authors read as non-inferiority at week 4 and superiority at weeks 8 and 12. On onset, the modified Sexual Encounter Profile 1 response was 84.8% for avanafil against 28.2% for sildenafil (P < 0.001).

Read those onset numbers as a laboratory property showing up in an outcome, not as a head-to-head efficacy verdict on a 220-patient sample.

The safety signal nobody can quantify

The 2024 analysis of the Eudra-Vigilance database, the European system for reporting suspected adverse reactions, recorded 951 major adverse cardiovascular events across the four drugs: 377 of 8,939 reports for sildenafil (4%), 221 of 5,213 for tadalafil (4%), 50 of 1,029 for vardenafil (4%) and no events at all for avanafil. No significant differences were reported between the drugs on pooled relative risk.

That zero is not evidence of lower cardiovascular risk. These are spontaneous reports, not incidence rates, and the report counts differ by almost tenfold between avanafil and sildenafil — a drug approved by the FDA in 2012 and dispensed by a much smaller volume of patients will generate fewer reports of anything. The 2023 WHO pharmacovigilance analysis was blunter about the same problem, reporting significant reporting-odds signals for priapism with sildenafil (reporting odds ratio 13.81, 95% CI 11.75 to 16.24), tadalafil (14.54, 95% CI 11.56 to 18.06) and vardenafil (14.12, 95% CI 8.36 to 22.35), and stating that analysis of pharmacovigilance data does not allow for quantifying clinical risk.

What the data do not show

They do not show that avanafil works better than sildenafil. The largest comparative synthesis on this page ranks it below sildenafil and below vardenafil on erectile function, and survives a threshold check only for sildenafil.

They do not show a patient-preference advantage. The 2015 comparison review notes that avanafil had no patient satisfaction trials to date, and the preference literature concludes that first-time response to any PDE5 inhibitor is around 60 to 70% with no significant efficacy differences among them.

They do not show anything about cardiovascular outcomes. The Eudra-Vigilance comparison is a reporting analysis and the abstract itself states that risk seems higher in younger patients, which is a signal about reporting, not about avanafil’s safety.

They do not show a half-life advantage. The pharmacokinetic study on this page records an apparent half-life of 5.36 to 10.66 hours; the 2013 review gives a terminal elimination half-life of five hours and notes that tadalafil is the agent with the longest half-life.

What the shelf does and does not contain

The row on this page is the generic active substance as supplied by the manufacturer. The comparators on every study quoted here are prescription drugs studied under regulatory programmes in specific populations — men with ED, including subgroups with diabetes type I and II and men after nerve-sparing radical prostatectomy. Nothing on this page measures a powder in a vial, and the reader should not treat the trial numbers as a characterisation of the preparation.

Where this sits on the shelf

The compounds as supplied by the manufacturer: Avanafil 200 mg · Avanafil 100 mg

What we supply

The avanafil preparations above, as supplied by the manufacturer, tracked, from inside the EU.

Research use only. This page summarises published studies for research reference. It is not medical advice, not a protocol, and not a suggestion for human use. Nothing we supply is for human or veterinary use.