Drug Guide

Generic Name

Lubiprostone

Brand Names Amitiza

Classification

Therapeutic: Laxative, Chloride Channel Activator

Pharmacological: Prostaglandin derivative, Chloride channel activator

FDA Approved Indications

  • Chronic idiopathic constipation in adults
  • Irritable bowel syndrome with constipation (IBS-C) in women aged 18 and older
  • Opioid-induced constipation in adults

Mechanism of Action

Lubiprostone activates type 2 chloride channels (ClC-2) on the apical aspect of intestinal epithelial cells, leading to increased chloride-rich fluid secretion into the intestinal lumen, which helps facilitate bowel movements.

Dosage and Administration

Adult: Initially 24 mcg twice daily with food and water. Dosage may be adjusted based on response and tolerability.

Pediatric: Not approved for pediatric use.

Geriatric: Same as adult; monitor renal and hepatic function as appropriate.

Renal Impairment: Use with caution; no specific dose adjustment recommended but assessment is advised.

Hepatic Impairment: Use with caution; no specific dose adjustment recommended but assessment is advised.

Pharmacokinetics

Absorption: Rapid absorption, bioavailability approximately 12%, unaffected by food.

Distribution: Low plasma protein binding (~8%).

Metabolism: Primarily hepatic via hydrolysis; minimal formation of active metabolites.

Excretion: Fecal (main), minimal urinary excretion.

Half Life: Approximately 3-6 hours.

Contraindications

  • Mechanical gastrointestinal obstruction
  • Severe diarrhea

Precautions

  • Use cautiously in patients with electrolyte abnormalities, history of bowel obstruction or with worsening abdominal symptoms, and in those taking medications affecting fluid/electrolyte balance.

Adverse Reactions - Common

  • Nausea (Common)
  • Diarrhea (Common)
  • Headache (Uncommon)

Adverse Reactions - Serious

  • Dehydration (Rare)
  • Serious diarrhea leading to dehydration or electrolyte imbalance (Rare)

Drug-Drug Interactions

  • CYP2C8 inhibitors (e.g., gemfibrozil) may increase lubiprostone levels—monitor and consider dose adjustments.

Drug-Food Interactions

  • No significant interactions reported.

Drug-Herb Interactions

  • No specific data available.

Nursing Implications

Assessment: Assess bowel function, electrolyte levels, hydration status, and abdominal status prior to initiation.

Diagnoses:

  • Constipation
  • Risk for electrolyte imbalance
  • Dehydration

Implementation: Administer with food and water as prescribed, monitor for effectiveness and adverse effects, especially diarrhea and dehydration.

Evaluation: Assess for increase in bowel movements, relief of constipation, and monitor for adverse effects.

Patient/Family Teaching

  • Take as directed with food and water.
  • Report severe or prolonged diarrhea, dehydration, or abdominal pain.
  • Maintain adequate fluid intake.

Special Considerations

Black Box Warnings:

  • None specific, but caution in patients with mechanical GI obstruction.

Genetic Factors: No known genetic considerations affecting use.

Lab Test Interference: No significant laboratory interferences reported.

Overdose Management

Signs/Symptoms: Severe diarrhea, dehydration, electrolyte imbalance, abdominal pain.

Treatment: Supportive care, restore hydration and electrolytes, monitor vital signs and laboratory parameters.

Storage and Handling

Storage: Store at room temperature, 20°C to 25°C (68°F to 77°F).

Stability: Stable under recommended storage conditions; discard after expiration.

This guide is for educational purposes only and is not intended for clinical use.