Papaverine / Phentolamine Solution

Alprostadil / Papaverine / Phentolamine Solution
Usage
Alprostadil, papaverine, and phentolamine solution is a compounded medication used in the treatment of erectile dysfunction (ED). This combination is commonly referred to as intracavernosal injection therapy and is typically prescribed when oral medications for erectile dysfunction are ineffective or not suitable.
The combination works by relaxing smooth muscle and increasing blood flow to the penis, facilitating the development and maintenance of an erection sufficient for sexual activity. Treatment should be initiated and supervised by a qualified healthcare professional, with appropriate patient education on administration technique.

Dosage
Dosage must be individualised and determined by the prescribing practitioner, usually beginning with a low test dose administered under medical supervision.
Typical considerations include:
• The solution is administered by intracavernosal injection into the corpus cavernosum of the penis.
• The starting dose is usually titrated gradually until an adequate response is achieved.
• Injections are generally limited to no more than once within a 24-hour period and no more than 2–3 times per week, unless otherwise directed by the prescriber.
• The lowest effective dose should be used to minimise the risk of adverse effects.
Patients should receive training from a healthcare professional before self-administration.

Mechanisms of Action
This combination contains three agents that work synergistically to increase penile blood flow.
Alprostadil
Alprostadil (prostaglandin E1) promotes vasodilation by increasing cyclic adenosine monophosphate (cAMP) within smooth muscle cells, leading to relaxation of the corpus cavernosum and increased arterial blood flow.
Papaverine
Papaverine is a non-specific phosphodiesterase inhibitor that increases intracellular levels of cyclic nucleotides, causing smooth muscle relaxation and vasodilation.
Phentolamine
Phentolamine is an alpha-adrenergic receptor antagonist that blocks sympathetic-mediated vasoconstriction, allowing increased blood flow into penile erectile tissue.
Together, these agents enhance smooth muscle relaxation, increased blood inflow, and reduced venous outflow, promoting erection.

Contraindications
This medication should not be used in patients with:
• Hypersensitivity to any component of the formulation
• Conditions predisposing to priapism, such as sickle cell anaemia, leukaemia, or multiple myeloma
• Anatomical deformation of the penis, including severe penile fibrosis or Peyronie’s disease
• Penile implants or other conditions where intracavernosal injection is not appropriate
• Patients for whom sexual activity is contraindicated due to cardiovascular conditions

Precautions
Use with caution in patients with:
• Bleeding disorders or those taking anticoagulant therapy
• Cardiovascular disease
• History of priapism or prolonged erections
• Penile fibrosis or scarring
Additional precautions include:
• Incorrect injection technique may lead to pain, bruising, or fibrosis.
• Patients should seek immediate medical attention if an erection lasts longer than 4 hours (priapism).
• Injection sites should be alternated to reduce the risk of tissue damage.
Patients should only use this medication according to prescriber instructions.

Storage
Storage requirements may vary depending on the specific compounded formulation.
General recommendations include:
• Store in a refrigerator (2–8°C) unless otherwise directed by the pharmacy.
• Protect from light and keep the container tightly closed.
• Do not freeze the solution unless specifically instructed.
• Keep out of reach of children and pets.
Patients should follow the specific storage instructions provided on the dispensing label supplied by the pharmacy.