Erectile Function After Radical Prostatectomy: What Penile Rehabilitation Can and Can't Restore
A single patient, six weeks past nerve-sparing radical prostatectomy, asking for the daily pill he read protects erectile function long-term. The disagreement is less about whether to prescribe it than about what the group is honestly promising him if they do.
Walter S., a 61-year-old retired high school principal, is six weeks past a bilateral nerve-sparing robotic radical prostatectomy for organ-confined Gleason 7 prostate cancer — an undetectable PSA and, before surgery, entirely normal erectile function. He has had no erections, spontaneous or otherwise, since the operation, which his surgeon has told him is expected this early while the cavernous nerves recover from surgical trauma. What brought him back sooner than his scheduled follow-up is something he read online about “penile rehabilitation”: a daily pill, started early, that he understood would protect his long-term chances of getting back to where he was.
REACTT, the trial that established daily tadalafil as the standard rehabilitation regimen, supports about half of what he came in believing. It randomized 423 men under 68 with normal preoperative function to tadalafil 5 mg once daily, tadalafil 20 mg on demand, or placebo for nine months after nerve-sparing prostatectomy. Both tadalafil arms significantly beat placebo on drug-assisted erectile function during that nine months, and the once-daily arm specifically showed less penile length loss than placebo — a real, if modest, structural benefit, 4.1 millimeters on average. But the trial’s actual primary endpoint was unassisted erectile function after a six-week drug-free washout, testing whether the drug had genuinely rehabilitated the nerves rather than just treated the symptom while running — and on that measure, neither tadalafil arm significantly beat placebo. The pill Walter read about helps him have erections while he’s taking it and may protect some penile length; it has not been shown to give him back spontaneous erections once he stops, a distinction his surgeon has not yet had the chance to walk him through.
In the post-operative urology follow-up
Start daily tadalafil 5 mg now, per REACTT. He's exactly the population that trial enrolled — normal preoperative function, bilateral nerve-sparing surgery, early in the postoperative window — and the drug-assisted benefit and penile length preservation are both real trial findings, not something we're extrapolating.
The length preservation is real — 4.1 millimeters, a specific, modest, statistically significant number — and I'm not arguing against starting the drug. I'm arguing against the word he used walking in: 'rehabilitation.' REACTT's actual primary endpoint, unassisted erectile function after drug-free washout, was not significantly better than placebo in either tadalafil arm. If we let him leave today believing this pill is restoring his nerves, we're promising something the trial that justifies prescribing it didn't show.
Citing 'drug-assisted benefit' as if it answers the rehabilitation question skips past the actual primary endpoint the trial was designed to test — and that's the one that came back negative.
I don't think this is a disagreement about the prescription — I think it's a disagreement about what we tell him while writing it. Start the tadalafil, because the assisted-function and length data are real reasons to. But be explicit that this treats his function now and may protect some length, and that whether his own erections come back on their own is still an open question independent of whether he takes this pill.
Agreed: start daily tadalafil 5 mg, explicitly framed to Walter as treating his erectile function now and possibly protecting penile length, not as restoring spontaneous erections — with a nine-month drug-free washout trial built into his follow-up schedule to actually test where his unassisted function stands.
Not agreed: whether to fight his insurance for daily-dosing coverage or accept on-demand sildenafil as a practical substitute if that fight fails. The surgeon wants to pursue daily coverage on the strength of the REACTT protocol; the pharmacologist sees on-demand as a reasonable compromise anyway, given how equivocal the actual rehabilitation evidence already is.