alprostadil (intracavernosal)

Absorption: Action is primarily local following intracavernosal injection.

Distribution: Unknown.

Metabolism/Excretion: Mostly metabolized locally; any systemically absorbed alprostadil is metabolized in the liver.

Half-Life: 5–10 min.

Time/Action Profile ⬆ ⬇

(erection)

ROUTE	ONSET	PEAK	DURATION
Intracavernosal	5–10 min	within 20 min	1 hr

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Penile implants;
Penile abnormalities;
Balanitis;
Men for whom sexual activity is not advisable;
Conditions predisposing to priapism (e.g., sickle cell anemia/trait, multiple myeloma, leukemia).

Use Cautiously in:

Severe coagulation abnormalities or thrombocytopenia;
Patients taking anticoagulants or antihypertensive agents.

Adv. Reactions/Side Effects ⬆ ⬇

CV: hypertension, hypotension

GU: penile pain, penile edema, penile fibrosis, penile rashes, priapism

Local: bleeding, ecchymosis, hematomas, irritation

MS: back pain

Neuro: dizziness, headache

Resp: cough

Interactions ⬆ ⬇

Drug-drug:

Should not be used with other vasoactive agents.
↑risk of bleeding at injection site with anticoagulants.

Route/Dosage ⬆ ⬇

Intracavernosal(Adults ): 1.25–2.5 mcg initially; dose titrated as needed. Should not be used more than 3 times/wk. There should be ≥24 hr between doses. Doses >40 mcg (Edex) or >60 mcg (Caverject) should not be used.

Availability ⬆ ⬇

Powder for injection (Caverject): 20 mcg/vial; 40 mcg/vial
Powder for injection (prefilled syringe/cartridge) (Caverject Impulse and Edex): 10 mcg; 20 mcg; 40 mcg (Edex only)

Assessment ⬆ ⬇

Monitor for hypotension during in-clinic dosing.

Implementation ⬆ ⬇

Intracavernosal Injection: Reconstitution: Reconstitute Caverject with 1 mL of bacteriostatic water with benzyl alcohol. For Caverject Impulse and Edex, follow manufacturer's instructions for reconstitution. Do not shake. Use solution immediately; do not freeze or store. Do not administer solutions that are discolored or contain precipitates. A ½-in 29- to 30-gauge needle is used for injection. Injection must take place under sterile conditions. Injection site is usually along the dorsolateral aspect of the proximal third of the penis. Avoid visible veins. Alternate sides of the penis with each injection. Swab site with alcohol before injection. AutoInjector (PenInject 2.25) is available for self-injection.

Patient/Family Teaching ⬆ ⬇

Instruct patient in correct technique for use of medication.
Caution patient to report priapism (erection lasting 4 hr or longer) to health care professional immediately. Priapism is a medical emergency that can result in penile tissue damage and permanent loss of potency if not treated promptly.
- Caution patient about rapid change in position, especially within an hr of administration.
- Caution patient that use of alprostadil offers no protection against sexually transmitted infections (STIs). Injection of alprostadil may cause a small amount of bleeding at injection site, increasing risk of transmission of bloodborne diseases. Advise patient to use protective measures to prevent spread of STIs, including HIV.
Intracavernosal Injection: Instruct patient on correct technique for preparation, injection, and disposal of equipment. Caution patient not to reuse or share needle with other persons. Desirable dose is determined with first injection in health care professional’s office. Advise patient not to increase dose without consulting health care professional. Injections should be administered no more than 3 times/wk, with 24 hr between injections. Advise patient to notify health care professional if nodules or hard tissue in the penis; redness, swelling, or tenderness; or curvature of the erect penis occurs. Advise patient to read Patient Information before starting therapy and with each Rx refill in case of changes.
- Emphasize the importance of follow-up exams every 3 mo to assess efficacy and safety of therapy and to adjust dose as needed.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇

Pharmacokinetics ⬆ ⬇