Lubiprostone

• Chronic Idiopathic Constipation
• Irritable Bowel Syndrome with Constipation
• Opioid-Induced Constipation

Lubiprostone is a locally acting chloride channel activator used to treat chronic idiopathic constipation (CIC), irritable bowel syndrome with constipation (IBS-C), and opioid-induced constipation (OIC). As the first FDA-approved medication in its class, lubiprostone represents an important therapeutic option for patients with difficult-to-treat constipation syndromes.

Mechanism of Action

Lubiprostone activates ClC-2 chloride channels on the apical (luminal) membrane of intestinal epithelial cells. This activation increases chloride-rich fluid secretion into the intestinal lumen without altering serum sodium or potassium concentrations. The increased intestinal fluid softens stool, accelerates intestinal transit time, and facilitates spontaneous bowel movements. Unlike stimulant laxatives, lubiprostone works through a specific molecular target and does not cause electrolyte imbalances or dependence.

Available Formulations

Lubiprostone is available as soft gelatin capsules:

• 8 mcg capsules: For IBS-C
• 24 mcg capsules: For CIC and OIC

The medication should be taken with food and water to minimize nausea, the most common side effect.

Medical Uses

FDA-Approved Indications:

• Chronic idiopathic constipation in adults
• Irritable bowel syndrome with constipation in women 18 years and older
• Opioid-induced constipation in adults with chronic non-cancer pain

The medication provides relief typically within 24-48 hours for many patients, with sustained benefit during continued therapy.

Dosing Guidelines

• CIC: 24 mcg twice daily with food and water
• IBS-C: 8 mcg twice daily with food and water
• OIC: 24 mcg twice daily with food and water

Dose reduction to 24 mcg once daily may be considered for patients with nausea. For patients with severe hepatic impairment (Child-Pugh Class C), starting doses should be reduced.

Important Safety Information

Contraindications:

• Known or suspected mechanical gastrointestinal obstruction
• Hypersensitivity to lubiprostone

Warnings and Precautions:

• Patients should be assessed for mechanical obstruction prior to initiating therapy
• Caution in patients with severe diarrhea
• Should not be prescribed for patients known to be pregnant (limited data)
• Nausea may be reduced by taking with food

Pregnancy Considerations: Lubiprostone is not recommended during pregnancy. Women of childbearing potential should have a negative pregnancy test before starting therapy and use effective contraception.

Drug Interactions

Lubiprostone has minimal systemic absorption, resulting in few drug interactions:

• Methadone: May reduce effectiveness of lubiprostone; higher doses may be needed
• Diphenylheptane opioids: May reduce lubiprostone efficacy

Special Populations

• Hepatic Impairment: Dose adjustment needed for moderate to severe impairment
• Renal Impairment: No dose adjustment required
• Elderly: No dose adjustment necessary; use with caution
• Pediatric: Safety and efficacy not established in children