MISO-FEM 200mcg TABLET

Indications

• Gastric ulcer
• Duodenal ulcer
• NSAID-induced peptic ulcer
• Termination of pregnancy following mifepristone
• Management of miscarriage

Dosage

Children: Oral preparations are not licensed for use in children under 3 years. For children aged 1–5 months, the dose is 1 mg/kg 3 times a day. For children aged 6 months to 2 years

Adults: For gastric and duodenal ulcers, the typical adult dose is 150 mg orally twice daily. For termination of pregnancy following mifepristone, the recommended dose is 400 micrograms orally.

Mechanism of action

Misoprostol stimulates prostaglandin E1 receptors on parietal cells in the stomach to reduce gastric acid secretion. It increases mucus and bicarbonate secretion, thickening the mucosal bilayer, and promotes the generation of new cells. In the uterus, Misoprostol binds to smooth muscle cells to enhance the strength and frequency of contractions, while also degrading collagen and reducing cervical tone.

Pharmacodynamics

Misoprostol acts as a prostaglandin E1 analog which is effective in reducing the risk of NSAID-induced gastric ulcers and is utilized in obstetric applications such as miscarriage management and abortion. Its onset of action varies by route: oral (8 minutes), sublingual (11 minutes), vaginal (20 minutes), and rectal (100 minutes), with durations of action ranging from approximately 2 to 4 hours.

Pharmacokinetics

Misoprostol is rapidly absorbed after oral administration, with bioavailability affected by food. It undergoes extensive first-pass metabolism, leading to a half-life of about 20-40 minutes. The drug is metabolized in the liver and its metabolites are eliminated primarily through the urine. The pharmacokinetic profile varies with administration route and formulation.

Contra-indications

• Hypersensitivity to misoprostol or any of its components
• Pregnancy (for certain indications such as termination)
• History of uterine rupture
• Severe cardiovascular disease
• Conditions where hypotension might precipitate severe complications

Adverse effects

• Diarrhea
• Abdominal pain
• Nausea
• Vomiting
• Headache
• Dizziness
• Uterine rupture (rare)
• Chills
• Fever
• Hot flushes
• Hypotension
• Malaise
• Toxic shock syndrome (rare)

Interactions

• Oxytocin (unknown additive effect)
• NSAIDs may have diminished efficacy when misoprostol is used concurrently

Precautions

• Monitor for coagulopathy during treatment
• Use with caution in patients with a history of inflammatory bowel disease
• Caution in patients with cardiovascular disease
• Patients should be informed about potential for diarrhea and other gastrointestinal side effects

Pregnancy

Not recommended during pregnancy except for specific medical indications such as termination of pregnancy following mifepristone, as it may induce contractions and lead to miscarriage.

Breast-feeding

Misoprostol is excreted in breast milk; caution is advised when administered to nursing mothers.

Storage

Store below 25°C. Protect from light and moisture.

Formulations

• Tablets: 200 micrograms, 400 micrograms
• Pessaries: 100 micrograms
• Oral solution

Mechanism of action

Misoprostol is a synthetic prostaglandin E1 analog that stimulates prostaglandin E1 receptors on parietal cells in the stomach to reduce gastric acid secretion. Mucus and bicarbonate secretion are also increased along with thickening of the mucosal bilayer so the mucosa can generate new cells. Misoprostol binds to smooth muscle cells in the uterine lining to increase the strength and frequency of contractions as well as degrade collagen and reduce cervical tone. Misoprostol enhances natural gastromucosal defense mechanisms and healing in acid-related disorders, probably by increasing production of gastric mucus and mucosal secretion of bicarbonate. Misoprostol inhibits basal and nocturnal gastric acid secretion by direct action on the parietal cells; also inhibits gastric acid secretion stimulated by food, histamine, and pentagastrin. It decreases pepsin secretion under basal, but not histamine stimulation. Misoprostol has no significant effect on fasting or postprandial gastrin or intrinsic factor output.

Pharmacodynamics

Misoprostol is a prostaglandin E1 analog used to reduce the risk of NSAID induced gastric ulcers by reducing secretion of gastric acid from parietal cells. Misoprostol is also used to manage miscarriages and used alone or in combination with mifepristone for first trimester abortions. An oral dose of misoprostol has an 8 minute onset of action and a duration of action of approximately 2 hours, a sublingual dose has an 11 minute onset of action and a duration of action of approximately 3 hours, a vaginal dose has a 20 minute onset of action and a duration of action of approximately 4 hours, and a rectal dose has a 100 minute onset of action and a duration of action of approximately 4 hours.