Lubiprostone

Pronunciation: LOO-bi-PROST-one
Class: GI agent

Trade Names

Amitiza
- Capsules 8 mcg
- Capsules 24 mcg

Pharmacology

Lubiprostone, a locally acting chloride channel activator, activates CIC-2, a normal constituent of the luminal membrane of the human intestine, which enhances a chloride-rich intestinal fluid secretion without altering sodium and potassium serum concentrations. By increasing intestinal fluid secretion, lubiprostone increases intestinal motility, which facilitates the passage of stool and alleviates symptoms associated with chronic idiopathic constipation.

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Pharmacokinetics

Absorption

Low systemic bioavailability. The C _max and mean AUC are 41.5 pg/mL and 57.1 pg•h/mL, respectively.

Distribution

Protein binding is about 94%.

Metabolism

Extensively metabolized by carbonyl reductase.

Elimination

Although not detectable in plasma, the t _½ ranges from 0.9 to 1.4 h. Elimination is 60% in urine and 30% in feces.

Peak

After a single oral dose of 24 mcg, peak levels occur at about 1.14 h.

Special Populations

Has not been evaluated.

Has not been evaluated.

No effect.

Indications and Usage

Treatment of chronic idiopathic constipation in adults; treatment of bowel syndrome with constipation in women 18 yr of age and older.

Contraindications

History of mechanical GI obstruction; hypersensitivity to any component of the product.

Dosage and Administration

PO 24 mcg twice daily.

PO 8 mcg twice daily with food or water.

General Advice

• Administer each dose with food and water to prevent or reduce nausea.
• Periodically assess need for continued therapy.

Storage/Stability

Store capsules at controlled room temperature (59° to 86°F).

Drug Interactions

None well documented.

Laboratory Test Interactions

None well documented.

Adverse Reactions

Cardiovascular

Increased heart rate, syncope (postmarketing).

CNS

Headache (11%); dizziness (3%); fatigue (2%); asthenia, malaise (postmarketing).

Dermatologic

Rash (postmarketing).

GI

Nausea (29%); diarrhea (12%); abdominal pain (8%); abdominal distention, flatulence (6%); abdominal discomfort, loose stools, vomiting (3%); dyspepsia (2%); dry mouth, stomach discomfort (1%).

Hypersensitivity

Allergic-type reactions including rash, swelling, and throat tightness (postmarketing).

Musculoskeletal

Muscle cramps or spasms (postmarketing).

Respiratory

Dyspnea (3%).

Miscellaneous

Chest discomfort, edema (3%).

Precautions

Pregnancy

Category C .

Lactation

Undetermined.

Children

Safety and efficacy not established.

Elderly

Efficacy similar in elderly patients compared with younger individuals. Elderly patients experienced a lower rate of nausea compared with younger patients.

Safety similar in elderly patients compared with younger individuals.

Diarrhea

Do not administer to patients who have severe diarrhea.

GI obstruction

Evaluate patients with symptoms suggestive of mechanical GI obstruction prior to initiating therapy.

Overdosage

Symptoms

Abdominal pain, anorexia, asthenia, chest discomfort, diarrhea, dizziness, dry mouth, dyspnea, flushing or hot flush, headache, hyperhidrosis, nausea, pallor, retching, stomach discomfort, syncope, vomiting.

Patient Information

• Advise patient to review the patient information leaflet carefully before starting therapy and to read and check for new information each time the medication is refilled.
• Advise patient to take each dose with food and water to reduce the frequency and severity of nausea.
• Advise patient that therapy will be periodically evaluated by health care provider to determine if medication needs to be continued.
• Advise patient that abdominal bloating, discomfort, and/or pain; nausea; diarrhea; and gas occur commonly during treatment and to notify health care provider if symptoms occur and are intolerable.
• Advise women of childbearing potential to use effective contraception while taking lubiprostone.
• Women who could become pregnant should have a negative pregnancy test prior to beginning therapy and should use effective contraception during treatment.
• Instruct patients to swallow the medication whole and not to break or chew capsules.

Copyright © 2009 Wolters Kluwer Health.