Prolonged erection (priapism)

What's happening

Priapism is an involuntary erection that lasts more than four hours and doesn't go down after ejaculation. For anyone using trimix or another injection (ICP) therapy, it is the main serious risk to know cold, because acting quickly is what protects your long-term function. The trapped blood is starving the tissue of oxygen, and the damage clock is running the whole time. So this page runs on a clock too, with the actual numbers, because harm reduction means knowing what to do at hour two before it's hour three. (What the damage looks like, hour by hour, is the priapism clock.)

Lower the risk before it happens

• Never combine an injection with an oral ED pill. Don't take trimix or any ICP injection within the same 24 hours as Viagra, Cialis, Levitra, or similar.
• Start low, go slow. Standard programs start the first injection at no more than 0.05 mL (5 units on the syringe) and go up only in 0.05 mL steps under a prescriber's direction. Never self-adjust. The dose that works is almost never the dose that feels impressive.
• Keep your rescue plan within reach. If your prescriber gave you rescue instructions or a rescue medication, store them somewhere you can find in seconds, and read them once now, at peace, not for the first time at hour three.
• No rescue plan yet? Ask your prescriber for one before you need it: a written protocol and, where appropriate, a rescue prescription to keep on hand. That is a normal request in a competent injection program, not a paranoid one.

The ladder: act by the clock

The moves below are the ones published in standard patient handouts for injection therapy. We print the numbers because they already exist on paper in every good program, and freezing at hour three because you never saw them is the failure mode we're here to prevent. They are the ladder, not a substitute for it: at four hours, the ladder ends at the ER.

• Past your usual window, or approaching 2 hours: non-drug measures first. Apply an ice pack to the perineum or scrotal area (a frozen bag of vegetables works), and walk or climb stairs to redirect blood flow. These are real first steps, but know their limit: the urology guidelines are explicit that once this is a true ischemic priapism, ice, exercise, and pills are unlikely to fix it and must never delay definitive treatment.
• Still going around 2 to 3 hours: the over-the-counter step in standard handouts is pseudoephedrine 30 mg by mouth (the real Sudafed, sold behind the pharmacy counter, ID required) or diphenhydramine 25 to 50 mg (Benadryl). Pick one, not both. If you have heart disease, high blood pressure, or take interacting medications, skip straight to calling your prescriber or the ER instead.
• Around 3 hours, or the OTC step didn't work: prescription rescue, if your prescriber gave you one. The two standard options: terbutaline 10 mg once, then another 5 to 10 mg fifteen minutes later only if needed; or, phenylephrine HCl 0.1%: 0.25 mL injected into the penis every 3 to 5 minutes, up to a total of 1 mL (1,000 mcg) over no more than one hour, pressing on the injection site and massaging the shaft after each one so the drug spreads. Use these only as, and in the exact amounts, your prescriber told you. The numbers are printed here so you can recognize them and verify your own paperwork, not to replace it.
• At 4 hours (or sooner if it's severely painful): go to the ER. Now. The self-management phase is over. Nothing you take at home at hour four is a substitute for what they do there, and every hour past four raises the odds of permanent damage.
• Afterward: if you notice lumps, curvature, swelling, or tenderness, contact your prescriber. That is scar tissue forming, the same process behind Peyronie's disease, and early attention matters.

What the ER actually does: the reversal

Men delay because they imagine the ER visit is worse than the problem. It isn't. Here is the actual sequence, from the AUA/SMSNA priapism guideline:

• Confirm what kind it is. A blood sample is drawn from the penis (a corporal blood gas). Ischemic priapism, the kind injection therapy causes, shows up as dark, oxygen-starved blood, and it is the emergency.
• First-line reversal: drain and reverse. A needle goes into the corpora and the trapped blood is aspirated out, usually with saline irrigation, while phenylephrine, the reversal drug, is injected in small repeated doses until the erection comes down. Blood pressure and heart rate are monitored while they do it. For a prolonged erection from an injection, the same drug is the guideline's recommended treatment even before four hours.
• If that fails: a shunt. A small surgical window is made between the erection chambers and the head of the penis (a distal shunt, sometimes with tunneling) to let the blood drain. It is a last resort, but it exists, and it works when the drugs don't.
• The part nobody says out loud: after an ischemic event lasting more than about 36 hours, the guideline itself counsels that the likelihood of recovering erectile function is low, and early penile prosthesis placement becomes the conversation. That is the entire reason the four-hour rule exists. Go early and the fix is usually a needle and an afternoon. Wait and it can cost you erections permanently.

If you're struggling beyond the physical

Sexual health and mental health are tied together, and reaching out is the strong move. In the U.S., the 988 Suicide & Crisis Lifeline is free and confidential, 24/7. Call or text 988. Outside the U.S., contact your local emergency number or a crisis line in your country.