Alprostadil

U.S. BRAND NAMES — Caverject Impulse®; Caverject®; Edex®; Muse®; Prostin VR Pediatric®

PHARMACOLOGIC CATEGORY
Prostaglandin

DOSING: ADULTS
Erectile dysfunction:
Intracavernous (Caverject®, Edex®): Individualize dose by careful titration; doses >40 mcg (Edex®) or >60 mcg (Caverject®) are not recommended: Initial dose must be titrated in physician's office. Patient must stay in the physician's office until complete detumescence occurs; if there is no response, then the next higher dose may be given within 1 hour; if there is still no response, a 1-day interval before giving the next dose is recommended; increasing the dose or concentration in the treatment of impotence results in increasing pain and discomfort.
Vasculogenic, psychogenic, or mixed etiology: Initiate dosage titration at 2.5 mcg, increasing by 2.5 mcg to a dose of 5 mcg and then in increments of 5-10 mcg depending on the erectile response until the dose produces an erection suitable for intercourse, not lasting >1 hour; if there is absolutely no response to initial 2.5 mcg dose, the second dose may be increased to 7.5 mcg, followed by increments of 5-10 mcg
Neurogenic etiology (eg, spinal cord injury): Initiate dosage titration at 1.25 mcg, increasing to a dose of 2.5 mcg and then 5 mcg; increase further in increments 5 mcg until the dose is reached that produces an erection suitable for intercourse, not lasting >1 hour
Maintenance: Once appropriate dose has been determined, patient may self-administer injections at a frequency of no more than 3 times/week with at least 24 hours between doses
Intraurethral (Muse® Pellet):
Initial: 125-250 mcg
Maintenance: Administer as needed to achieve an erection; duration of action is about 30-60 minutes; use only two systems per 24-hour period

DOSING: PEDIATRIC

(For additional information see "Alprostadil: Pediatric drug information")
Patent ductus arteriosus I.V.:
Prostin VR Pediatric®: I.V. continuous infusion into a large vein, or alternatively through an umbilical artery catheter placed at the ductal opening: 0.05-0.1 mcg/kg/minute with therapeutic response, rate is reduced to lowest effective dosage. With unsatisfactory response, rate is increased gradually; maintenance: 0.01-0.4 mcg/kg/minute.
Note: PGE1 is usually given at an infusion rate of 0.1 mcg/kg/minute, but it is often possible to reduce the dosage to 1/2 or even 1/10 without losing the therapeutic effect. The mixing schedule is shown in the table.

Mixing Schedule

Note: 500 mcg equals 1 ampul. For a concentration of 2 mcg/mL, add 500 mcg to 250 mL; infuse at 0.05 mL/kg/minute (72 mL/kg/24 hours) For a concentration of 5 mcg/mL, add 500 mcg to 100 mL; infuse at 0.02 mL/kg/minute (28.8 mL/kg/24 hours) For a concentration of 10 mcg/mL, add 500 mcg to 50 mL; infuse at 0.01 mL/kg/minute (14.4 mL/kg/24 hours) For a concentration of 20 mcg/mL, add 500 mcg to 25 mL; infuse at 0.005 mL/kg/minute (7.2 mL/kg/24 hours)

Note: Therapeutic response is indicated by increased pH in those with acidosis or by an increase in oxygenation (PO2) usually evident within 30 minutes.

DOSING: ELDERLY — Refer to adult dosing.

DOSAGE FORMS — Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Injection, powder for reconstitution:
Caverject®: 20 mcg, 40 mcg [contains lactose; diluent contains benzyl alcohol]
Caverject Impulse®: 10 mcg, 20 mcg [prefilled injection system; contains lactose; diluent contains benzyl alcohol]
Edex®: 10 mcg, 20 mcg, 40 mcg [contains lactose; packaged in kits containing diluent, syringe, and alcohol swab]

Injection, solution: 500 mcg/mL (1 mL)
Prostin VR Pediatric®: 500 mcg/mL (1 mL) [contains dehydrated alcohol]

Pellet, urethral (Muse®): 125 mcg (6s), 250 mcg (6s), 500 mcg (6s), 1000 mcg (6s)

DOSAGE FORMS: CONCISE
Injection, powder for reconstitution: 10 mcg, 20 mcg, 40 mcg
Caverject®: 20 mcg, 40 mcg
Caverject Impulse®: 10 mcg, 20 mcg
Edex®: 10 mcg, 20 mcg, 40 mcg

Injection, solution: 500 mcg/mL (1 mL)
Prostin VR Pediatric®: 500 mcg/mL (1 mL)

Pellet, urethral: 125 mcg, 250 mcg, 500 mcg, 1000 mcg
Muse®: 125 mcg (6s), 250 mcg (6s), 500 mcg (6s), 1000 mcg (6s)

GENERIC EQUIVALENT AVAILABLE — Yes: Solution for injection

ADMINISTRATION — Erectile dysfunction: Use a 1/2 inch, 27- to 30-gauge needle. Inject into the dorsolateral aspect of the proximal third of the penis, avoiding visible veins; alternate side of the penis for injections.

USE
Prostin VR Pediatric®: Temporary maintenance of patency of ductus arteriosus in neonates with ductal-dependent congenital heart disease until surgery can be performed. These defects include cyanotic (eg, pulmonary atresia, pulmonary stenosis, tricuspid atresia, Fallot's tetralogy, transposition of the great vessels) and acyanotic (eg, interruption of aortic arch, coarctation of aorta, hypoplastic left ventricle) heart disease.

Caverject®: Treatment of erectile dysfunction of vasculogenic, psychogenic, or neurogenic etiology; adjunct in the diagnosis of erectile dysfunction

Edex®, Muse®: Treatment of erectile dysfunction of vasculogenic, psychogenic, or neurogenic etiology

USE - UNLABELED / INVESTIGATIONAL — Investigational: Treatment of pulmonary hypertension in infants and children with congenital heart defects with left-to-right shunts

ADVERSE REACTIONS SIGNIFICANT
Intraurethral:

>10%: Genitourinary: Penile pain, urethral burning

2% to 10%:
Central nervous system: Headache, dizziness, pain
Genitourinary: Vaginal itching (female partner), testicular pain, urethral bleeding (minor)

<2%>10%: Genitourinary: Penile pain

1% to 10%:
Cardiovascular: Hypertension
Central nervous system: Headache, dizziness
Genitourinary: Prolonged erection (>4 hours, 4%), penile fibrosis, penis disorder, penile rash, penile edema
Local: Injection site hematoma and/or bruising

<1%>10%:
Cardiovascular: Flushing
Central nervous system: Fever
Respiratory: Apnea

1% to 10%:
Cardiovascular: Bradycardia, hyper-/hypotension, tachycardia, cardiac arrest, edema
Central nervous system: Seizures, headache, dizziness
Endocrine & metabolic: Hypokalemia
Gastrointestinal: Diarrhea
Hematologic: Disseminated intravascular coagulation
Neuromuscular & skeletal: Back pain
Respiratory: Upper respiratory infection, flu syndrome, sinusitis, nasal congestion, cough
Miscellaneous: Sepsis, localized pain in structures other than the injection site

<1%>120 hours has been associated with antral hyperplasia and gastric outlet obstruction.

Special populations: Neonates: Use with caution in neonates with bleeding tendencies.

Dosage form specific issues: Muse®: When used in erectile dysfunction, syncope occurring within 1 hour of administration has been reported. The potential for drug-drug interactions may occur when prescribed concomitantly with antihypertensives. Some lowering of blood pressure may occur without symptoms, and swelling of leg veins, leg pain, perineal pain, and rapid pulse have been reported in <2%>4 hours to a prescriber immediately; inform a prescriber as soon as possible if any new penile pain, nodules, hard tissue, or signs of infection develop; the risk of transmission of blood-borne diseases is increased with use of alprostadil injections since a small amount of bleeding at the injection site is possible. Do not drive or operate heavy machinery within 1 hour of administration.

(For additional information see "Alprostadil: Patient drug information")

Erectile dysfunction: If the patient is going to be self-injecting at home, carefully assess his aseptic technique for injection and knowledge of proper disposal of the syringe, needle, and vial. Observe for signs of infection, penile fibrosis, and significant pain or priapism