Description�� Product Profile: AlprostadilGeneric Name: AlprostadilINN/USAN: AlprostadilCAS Number: 745-65-3Synonyms: Prostaglandin E1 (PGE1); 11α,15(S)-Dihydroxy-9-oxoprost-13-en-1-oic acidMolecular Formula: C₂₀H₃₄O₅Molecular Weight: 354.48 g/molDrug Class: Prostaglandin Analogue; Vasodilator; Platelet Aggregation Inhibitor�� Key CharacteristicsAlprostadil is an endogenous prostaglandin E1 (PGE1) with a cyclopentane ring structure and two hydroxyl groups at C-11 and C-15. As a white to off-white crystalline powder, it is practically insoluble in water but soluble in ethanol and chloroform. Pharmaceutical formulations include injectable solutions (5-10μg/mL in lipid microspheres for targeted delivery), urethral suppositories (125-1000μg), and cream preparations (0.25g:1mg). The lipid microsphere-encapsulated form enhances stability and tissue targeting, allowing rapid vascular uptake while minimizing systemic side effects.⚙️ Mechanism of ActionVasodilation: Activates adenylate cyclase, increasing intracellular cAMP levels to relax vascular smooth muscle—particularly in microvasculature and erectile tissue. This action improves blood flow in ischemic limbs and promotes penile tumescence by dilating cavernosal arteries.Antiplatelet Activity: Inhibits platelet aggregation via cAMP-mediated reduction of thromboxane A2 synthesis, preventing thrombus formation in transplant vasculature and occlusive arterial disease.Smooth Muscle Relaxation: Directly relaxes bronchial, gastrointestinal, and uterine smooth muscle, though clinical use primarily leverages vascular effects.Cellular Protection: Stabilizes lysosomal membranes and reduces inflammatory cytokine release in chronic liver disease models.�� Clinical ApplicationsIndicationFormulationDosageClinical EfficacyChronic Arterial OcclusionIV Injection (5-10μg/day)1-2mL diluted in 10mL saline, slow IV push or infusion qd for 2-4 weeksImproves rest pain (70% response rate) and promotes ulcer healing (55% closure at 8 weeks)Erectile DysfunctionUrethral Suppository (125-1000μg)Intracavitary administration 5-20 minutes pre-coitus; max 1 dose/24hAchieves adequate erections in 65-75% of patients; onset 5-10 minutes, duration 30-60 minutesNeonatal Arterial Duct DependenceIV Infusion (5-100ng/kg/min)Titrated to maintain ductal patency until surgical correctionMaintains oxygenation in 80% of critical congenital heart disease casesOrgan TransplantationIV Injection (10-20μg/kg/day)Added to preservation solution or post-op infusion to prevent microthrombosisReduces graft failure by 35% in renal transplant recipientsChronic HepatitisIV Injection (10μg/day)Adjunctive therapy for 4-8 weeksImproves ALT/AST levels in 40% of non-viral hepatitis patients⚠️ Safety ProfileAdverse Effects:Cardiovascular: Flushing (15%), hypotension (8%), palpitations (3%); rare worsening of heart failure.Local Reactions: Injection site pain/erythema (12%), penile pain (urethral suppositories: 25%), urethral burning (18%).Systemic: Headache (10%), diarrhea (7%), fever (4%); rare anaphylaxis (<0.1%).Contraindications: Severe heart failure, pregnancy, hypersensitivity to prostaglandins, and conditions predisposing to priapism (e.g., sickle cell anemia).Precautions: Use with caution in glaucoma (may increase intraocular pressure), peptic ulcer disease (risk of bleeding), and pulmonary edema.�� PharmacokineticsAbsorption: Rapid uptake via intravenous (100% bioavailability) or intraurethral (80% absorption within 10 minutes) routes; topical cream shows 3-5% systemic absorption.Metabolism: 60-90% cleared by pulmonary first-pass metabolism to inactive 15-keto-PGE1; plasma half-life: 2-5 minutes.Excretion: 90% of metabolites excreted in urine within 24 hours; minimal biliary elimination.�� Formulations & AvailabilityInjectables: Liposomal microsphere suspensions (5μg/1mL, 10μg/2mL), lyophilized powder for reconstitution (20μg/vial).Urethral Suppositories: Pellets (125μg, 250μg, 500μg, 1000μg) with applicator.Topical Cream: 0.4% concentration in single-use tubes.Global Brands: Prostavasin® (EU), Caverject® (urethral, US), Alprostadil Alfadex® (liposomal formulation, Japan).
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