Adults with pulmonary hypertension and erectile dysfunction are treated with alprostadil.

In newborns with congenital cardiac conditions such as tricuspid atresia, transposition of the great arteries, and Fallot's tetralogy, it is also utilised to keep the ductus arteriosus open until surgery can be done.

Alprostadil injection for ED (erectile dysfunction):

It is considered the second-line treatment in patients with ED. Phosphodiesterase inhibitors (like tadalafil, Verdenafil, and Sildenafil) are considered the first line of treatment. TRIMIX is a combination of papaverine, phentolamine, and alprostadil that is administered as an intracavernous injection for the treatment of ED. However, this is not marketed and available in pharmacies authorized to produce such mixtures. Alprostadil injection or injection of TRIMIX is considered a second-line treatment and as effective as oral phosphodiesterase inhibitors.

Alprostadil Cream for ED and Sexual arousal in females:

Alprostadil cream may be used for ED in men and sexual arousal disorder in women as well. Topical application may be specifically useful in patients who have contraindications to the use of oral sildenafil and diabetic patients with autonomic neuropathy. For diabetics, alprostadil cream can enhance their sexual experience. Furthermore, it is considered safe in cardiac patients and does not have any interactions with food or alcohol [Ref]. It is considered to be safe & effective and can be administered in patients on alpha-blockers, nitrates, and antihypertensive agents [Ref]. One study evaluated the intra-meatal administration of alprostadil (Vitaros) in patients with ED. The International Index of Erectile Function (IIEF-5) score change revealed that the drug's intra-meatal administration was more effective. [Ref].

Alprostadil suppository for ED:

The second-line therapy is alprostadil suppository for intraurethral administration since it has higher negative effects. The suppositories might cause penile burning, stinging, discomfort, and hypotension as side effects. Patients who have not responded well to treatment with either of the drugs might take alprostadil in combination with oral PDE inhibitors.[Ref].

Contraindications to Alprostadil:

• Alprostadil allergy in patients
• Respiratory distress syndrome
• Permanent fetal circulation or hyaline membrane disease
• Patients with certain conditions, such as leukaemia, sickle cell anaemia and multiple myeloma, are more likely to experience a penile erection.
• Patients with anatomically deformed penile shafts and patients with penile implanted penile
• Patients taking nitrates and patients who are not advised to have sexual activity.
• Fibrosis may be caused by Peyronie Disease of the Penis
• Patients with urethral strictures are advised to avoid intraurethral suppositories.
• Females who are pregnant

Warnings and precautions

• (US Boxed Warning):
• Babies that are underweight are more likely to have apnea (less than 2 kg).
• Alprostadil is prescribed to patients with erectile dysfunction. Patients should inform their physician if they experience an erection lasting more than four hours.
• Alprostadil should not be administered to neonates.
• Alprostadil over 120 hours for more than one hour has been linked to antral hyperplasia, gastric outlet obstruction, and gastric hyperplasia.
• Pregnant women with bleeding tendencies need to be cautious with the drug.

Alprostadil Dose in Adults

Alprostadil injection dosage for intracavernous administration (in the treatment of Erectile dysfunction):

(Note: Doses greater than 40 mcg (Edex®) or greater than 60 mcg (Caverject®) are not recommended)

• The patient may be given the first two doses in the physician's office one hour apart. After administration, the patient should remain in the physician's office until the erection subsides.
• The second dose is given to those who do not respond to the first dose.
• If an erection does not occur, the third dose should be given at intervals of 24 hours.
• The dose should be titrated upwards, starting from 2.5 mcg.
• A second dose of 7.5 mcg and then an incremental increase in the dose by 5-10 mcg may be followed if the response is not achieved.
• Patients who have erectile dysfunction of neurogenic origin like those with spinal cord injury should be initiated with a lower dose i.e. 2.5 mcg.
• Once the ideal dosage has been established, the patient may self-administer the medication up to three times per week, with a minimum of 24 hours in between doses.

Alprostadil injection dosage for Intraurethral administration:

• 125-250 mcg (use only two systems per day.

Alprostadil Dose in Children

Alprostadil (Caverject) injection dose in Children with PDA (Patent ductus arteriosus):

0.05–0.1 mcg/kg/min given intravenously in a continuous infusion. Once a therapeutic response has been seen, the dosage should be lowered to the lowest effective level.

Alprostadil Dose in renal disease:

• The manufacturer does not provide any dose adjustment in renal disease

Alprostadil Dose in Liver disease:

• The manufacturer does not provide any dose adjustment for Liver disease.

How to administer:

• In individuals with patent ductus arteriosus, alprostadil should be administered continuously intravenously into a big vein or through an umbilical artery catheter.
• The maximum concentration of the infusion should not exceed 20 mcg/ml.

How to administer alprostadil in patients with erectile dysfunction:

• Using a 1 / 2 inch, 27 to 30-gauge needle, inject alprostadil into the dorsolateral portion of the proximal third of the penis.
• Intravenous injections should be avoided, and the injection should be administered on opposite sides of the penis.

Pregnancy Risk Factor X

• Alprostadil is toxic to the fetus and is not indicated in females.
• In investigations on animals, it is embryotoxic. Women are not advised to use it. Breastfeeding mothers should not use it.

Alprostadil (Caverject) Side effects (Severe):

• Rapid:

  • Bradycardia

• Early:

  • cardiac arrest,
  • ventricular fibrillation,
  • penile edema,
  • visual impairment,

• Delayed:

  • apnea,
  • seizures,
  • phimosis,
  • myocardial infarction,
  • heart failure,
  • disseminated intravascular coagulation,
  • anuria, and
  • hyperkalemia.

Alprostadil Side effects (Moderate):

• Rapid:

  • Penile pain,
  • Urethral pain,
  • Hypotension,
  • Sinus tachycardia,
  • wheezing,
  • Respiratory depression, and
  • peripheral vasodilation

• Early:

  • Hematoma,
  • erythema,
  • Hypertension,
  • bleeding,
  • tachypnea,
  • Supraventricular tachycardia,
  • priapism,
  • hypoglycemia, and
  • urinary retention

• Delayed:

  • Penile fibrosis,
  • peripheral edema,
  • hypertriglyceridemia,
  • edema,
  • hyperemia,
  • thrombocytopenia,
  • anemia,
  • hyperbilirubinemia,
  • hematuria,
  • hypercholesterolemia, and
  • hyperglycemia.

Alprostadil Side effects (mild):

• Rapid:

  • Injection site reaction,
  • flushing, and
  • pruritis,

• Early:

  • Fever,
  • testicular pain,
  • dizziness,
  • headache,
  • rhinitis,
  • diarrhea,
  • lethargy,
  • syncope,
  • mydriasis,
  • nausea,
  • xerostomia,
  • rash,
  • diaphoresis,
  • weakness,
  • urinary urgency, and
  • increased urinary frequency

• Delayed:

  • Ecchymosis,
  • back pain,
  • hypothermia,
  • irritability,
  • muscle cramps,
  • gastroesophageal reflux, and
  • hypoesthesia

Monitoring Parameters:

• Keep an eye on your temperature, heart rate, and blood pressure.
• Monitoring the breathing rate of newborns receiving intravenous infusions is one way to check for apnea.
• Monitor for the degree and duration of erection in men.

Alprostadil mechanism of Action: 

Smooth muscle relaxation is caused by Alprostadil in the vessels, cavernosal and ductus arteriosus.

Rapid action starts and lasts for one hour. Approximately 75% of by is digested by oxidation in a single lung passageway.

Elimination takes 5–10 minutes after half-life.

90% of the metabolites are excreted mostly through the urine within 24 hours.

Alprostadil in Pakistan and Price:

CAVERJECT (PFIZER LABORATORIES LTD)

Injection : 20 mcg/ml :

one injection pack: Rs. 9500

PROSTAVASIN (ATCO LABORATORIES LIMITED)

Injection : 20 mcg/ml :

10 injection pack: Rs. 12000.00 per vial

Alprostadil creams and suppositories are currently not available in Pakistan.

Alprostadil Brand names (International):

• Alostin
• Alprostan
• Alprostapint
• Caverject Impulse
• Caverjet
• Edex
• Eglandin
• Minprog
• Muse
• Palux
• Prink
• Promostan
• Caverject
• Caverject Dual Chamber
• Prostandin
• Prostavasin
• Prostin
• Prostin Pediatrico
• Prostin VR
• Gaverject
• Liple
• Prostin VR Paedeatric
• Prostine VR
• Prostivas
• Sugiran
• Viridal