Short answer: In the label's studies of 1,861 men treated for up to 18 months, the most common Caverject side effect was penile pain (37%), mostly mild or moderate. Prolonged erection (4 to 6 hours) occurred in 4% and priapism (6 hours or more) in 0.4%. Penile fibrosis, injection site bruising and other local reactions were 3% or less. Caverject has no boxed warning.
What Caverject is approved for: Caverject is approved to treat erectile dysfunction, and as an add-on to other tests in diagnosing erectile dysfunction (sections 1.1 and 1.2). It is injected into the side of the penis (intracavernosal use).
Source
CAVERJECT (alprostadil) for injection, for intracavernosal use, prescribing information, Patient Information and Instructions for Use. Pharmacia & Upjohn (Pfizer). DailyMed, version published May 17, 2024. DailyMed setid a295fc1e-d82c-4f44-bc2d-a552bf594c98
No. The current Caverject label has no boxed warning.
These are the label's own numbers from the Adverse Reactions section. Where the label compares with placebo (a dummy treatment), both columns are shown, so you can see how much more often a reaction happened on Caverject.
| Local adverse reaction | CAVERJECT |
|---|---|
| Penile pain | 37% |
| Prolonged erection | 4% |
| Penile fibrosis | 3% |
| Injection site hematoma | 3% |
| Penis disorder | 3% |
| Injection site ecchymosis | 2% |
| Penile rash | 1% |
| Penile edema | 1% |
1,861 patients, including an 18-month open-label study. In the 294 patients on placebo, the only local reaction was penile pain (2%). Penis disorder includes numbness, irritation, sensitivity, itching, redness, skin tear and discoloration.
Penile pain was rated mild or moderate in most cases; 3% of patients stopped treatment because of it.
Prolonged erection (4 to 6 hours) occurred in 4% of 1,861 patients treated up to 18 months; priapism (more than 6 hours) in 0.4%.
Penile fibrosis was 3% overall in clinical studies, and 7.8% in one self-injection study lasting up to 18 months.
Whole-body side effects at 1% or more: dizziness (1%). Three patients (0.2%) stopped because of symptomatic low blood pressure. No whole-body reactions were reported on placebo.
Reported after approval: needle breakage during injection, sometimes needing surgical removal.
The Warnings and Precautions part of the label lists these. Each line gives the label's heading and what it means in plain words.
Who should not use it. Caverject is not used by men allergic to it, men with conditions that make priapism more likely (sickle cell anemia or trait, multiple myeloma, leukemia), men with penile fibrosis or deformity such as Peyronie's disease, or men with penile implants.
Prolonged erection and priapism. An erection lasting longer than 4 hours needs immediate medical help; untreated priapism can cause penile tissue damage and permanent loss of potency. Using the lowest effective dose lowers the risk.
Penile fibrosis. Scarring inside the penis can occur, so the penis is examined periodically. Caverject is stopped if curvature (angulation) or cavernosal fibrosis develops.
Low blood pressure. Injection can raise alprostadil levels in the blood and lower blood pressure. It is avoided with known cavernosal venous leakage.
Bleeding with blood thinners. People on warfarin or heparin may bleed more at the injection site; the site is pressed for 5 minutes.
Heart risk of sexual activity. ED treatments, including Caverject, generally are not used in men for whom sexual activity is inadvisable because of heart disease.
Combining with other penile injections. Combinations with other vasoactive drugs injected into the penis have not been studied and may raise the risk of prolonged erection, priapism and low blood pressure.
Needle breakage. Broken needle pieces left in the penis have been reported, some needing hospital surgery. Separate needles are used for mixing and injecting, and bent needles are not used or straightened.
From the Patient Counseling Information (section 17) that comes with Caverject:
Dose Track has a side-effect log. Each entry records the symptom, a severity (none, mild, moderate, severe or life-threatening), the date and an optional note, and can be tied to a specific dose or logged on its own. The history screen shows what you logged over time, which makes it easier to tell your prescriber when a reaction started and whether it is easing. The app records what you enter; it does not judge whether a symptom is serious. For anything on the label's call-your-doctor list, call your doctor.
This page is what the FDA label says, in plain words. It is not medical advice. Follow your prescriber, and ask them or your pharmacist about anything here.