ED Injections (Trimix & Quadmix)

Trimix and Quadmix are compounded injectable medications used by men with erectile dysfunction. They are typically considered after assessment by a prescriber, often when oral medications are not the right fit or have not worked as expected.

These prescriptions require careful dose titration and in-person teaching from the care team before independent use.

Trimix contains three active ingredients:

• Alprostadil — a prostaglandin that dilates blood vessels
• Papaverine — relaxes smooth muscle
• Phentolamine — blocks alpha-adrenergic receptors

Quadmix adds a fourth ingredient:

• Atropine — enhances the effects of the other three ingredients

These ingredients work together to relax the smooth muscles of penile blood vessels, allowing greater blood flow and producing an erection.

Potential side effects include:

• Headache or dizziness
• Injection site bruising or bleeding
• Penile pain (can be minimized with proper technique)
• Prolonged erection (priapism — seek medical attention if erection lasts over 4 hours)

Do not use if you:

• Are allergic to any of the ingredients
• Have conditions predisposing to priapism (sickle cell anemia, multiple myeloma, leukemia)
• Have anatomical deformation of the penis or a penile implant
• Have been told by your physician that sexual activity is inadvisable

• Store in the freezer
• Check the expiry date on the label

ED injection prescriptions should be used after injection teaching and dose instructions from the prescriber or trained care team.

For the patient handout, see the Trimix injection instructions. The handout is not a replacement for individualized teaching, dose titration, or emergency instructions for prolonged erection.