Misoprostol is a synthetic prostaglandin E1 (PGE1) analogue. In the Indian context, the 25mcg strength is primarily used for the prevention and treatment of NSAID-induced gastric and duodenal ulcers, particularly in high-risk patients on long-term NSAID therapy. It acts as a gastric mucosal protectant by enhancing local mucosal defense mechanisms and inhibiting gastric acid secretion.
Adult: For prevention/treatment of NSAID-induced ulcers: 100 to 200 mcg per day in 2 to 4 divided doses. The 25mcg tablet is typically used as 1 tablet (25mcg) four times daily with meals and at bedtime, OR 2 tablets (50mcg) twice daily. Must be taken with or after meals and at bedtime to maximize efficacy and minimize diarrhea.
Note: Take orally with a full glass of water. MUST be taken with food (preferably the last meal of the day and at bedtime) to reduce the incidence of diarrhea. Do not crush or chew the tablet. Swallow whole. For optimal gastric protection, the last dose should be taken at bedtime.
Misoprostol replaces the prostaglandins (specifically PGE1) whose synthesis is inhibited by NSAIDs. It exerts a dual protective action: 1) Antisecretory: Inhibits basal, nocturnal, and stimulated gastric acid secretion by directly acting on parietal cells via prostaglandin receptors linked to inhibitory G-proteins, reducing cAMP production. 2) Cytoprotective: Enhances mucosal blood flow, stimulates bicarbonate and mucus secretion (increasing mucosal thickness and gel layer), and promotes epithelial cell proliferation and migration, thereby strengthening the gastric mucosal barrier.
Pregnancy: CATEGORY X. ABSOLUTELY CONTRANDICATED. Can cause uterine contractions, miscarriage, incomplete abortion, premature birth, and fetal birth defects (e.g., cranial nerve palsies, facial malformations, Möbius syndrome). Women of childbearing potential must have a negative pregnancy test prior to therapy, use effective contraception, and be counseled on the risks.
Driving: Dizziness and headache have been reported. Patients should not drive or operate machinery if they experience these effects.
| Antacids (containing Magnesium) | May increase the incidence and severity of misoprostol-induced diarrhea. | Moderate |
| Oxytocin, other uterotonics | Potentiates uterine contractions, increasing risk of uterine hyperstimulation and rupture. | Major |
| NSAIDs (e.g., Ibuprofen, Diclofenac, Aspirin) | Misoprostol is used to counteract their ulcerogenic effect. No direct PK interaction, but this is a therapeutic combination. | N/A (Therapeutic) |
| Anticoagulants (Warfarin, NOACs) | Theoretical increased risk of bleeding due to prostaglandin effects on platelets and gastric mucosa, but misoprostol is protective. Monitor for GI bleeding. | Moderate |
Same composition (Misoprostol (25mcg)), different brands: