Entereg (alvimopan)

Entereg (alvimopan) is an opioid receptor antagonist that works by preventing narcotic side effects without reducing the pain-relieving effects of the drug used to speed recovery of stomach and intestinal functions after a gastrointestinal surgery and to prevent side effects caused by narcotic medications.

Common side effects of Entereg include:

• stomach pain or upset,
• indigestion,
• nausea,
• vomiting,
• diarrhea,
• constipation,
• gas,
• bloating, or
• back pain

• For hospital use only.
• The recommended adult dosage of Entereg is 12 mg administered 30 minutes to 5 hours prior to surgery followed by 12 mg twice daily beginning the day after surgery until discharge for a maximum of 7 days.
• Patients should not receive more than 15 doses of Entereg.
• Entereg can be taken with or without food.

Effects Of Alvimopan On Intravenous Morphine

• Coadministration of alvimopan does not appear to alter the pharmacokinetics of morphine and its metabolite, morphine-6-glucuronide, to a clinically significant degree when morphine is administered intravenously.
• Dosage adjustment for intravenously administered morphine is not necessary when it is coadministered with Entereg.

Effects Of Concomitant Acid Blockers Or Antibiotics

• A population pharmacokinetic analysis suggests that the pharmacokinetics of alvimopan were not affected by concomitant administration of acid blockers (proton pump inhibitors (PPIs), histamine-2 (H₂) receptor antagonists) or antibiotics.
• No dosage adjustments are necessary in patients taking acid blockers or antibiotics with Entereg.

• Available data regarding use of Entereg in pregnant women are limited, and are insufficient to inform a drug-associated risk of major birth defects, miscarriage or adverse maternal or fetal outcomes.
• There are no data on the presence of alvimopan in human milk, the effects on the breastfed infant, or the effects on milk production.
• Alvimopan and its 'metabolite' are detected in the milk of lactating rats following intravenous administration.