Entereg (alvimopan)
Last reviewed · Source: First Databank (FDB) drug data
Overview
Alvimopan is a peripherally acting micro-opiate receptor antagonist.
Alvimopan is a peripherally acting micro-opiate receptor antagonist.
Multiple factors (e.g., neurogenic, inflammatory, hormonal, pharmacologic) contribute to impaired GI motility following intra-abdominal surgery. The mechanism of action of alvimopan in the treatment of postoperative ileus stems from the drug's ability to block micro-opiate receptors in the GI tract, thereby antagonizing the peripheral inhibitory effects of opiates on GI motility and improving GI function. The drug does not readily cross the blood-brain barrier and therefore does not affect opiate analgesic activity or precipitate opiate withdrawal, as is observed with centrally active opiate antagonists (e.g., naloxone).
Alvimopan exhibits greater affinity for micro-opiate receptors than for delta- and kappa-opiate receptors and is a more potent micro-opiate receptor antagonist than is naloxone. Alvimopan does not appear to possess opiate agonist activity, nor does it possess affinity for nonopiate receptors, including alpha1-, alpha2-, and beta-adrenergic; dopamine types 1 and 2 (D1, D2); serotonin type 2 (5-hydroxytryptamine (5-HT2A)); histamine (H1); gamma-aminobutyric acid (GABA); benzodiazepine; and muscarinic receptors. In vitro studies have identified some differences in how alvimopan and methylnaltrexone (both peripheral micro-receptor antagonists) interact with opiate receptors (e.g., differences in binding affinity and functional activity) (see Description in Methylnaltrexone Bromide 56:92); however, it remains to be determined whether these differences are clinically important.
The absolute bioavailability of oral alvimopan averages 6% (range 1-19%). Orally administered alvimopan (unabsorbed drug and unmetabolized drug that reenters the intestine via biliary secretions) is metabolized by intestinal flora to an active, amide hydrolysis compound; however, the presence of this metabolite is not required for pharmacologic activity of alvimopan. Concentrations of alvimopan and its metabolite tend to be higher in patients with postoperative ileus than in healthy individuals; however, there is substantial intraindividual and interindividual variation in plasma concentrations of the metabolite.
The drug and its metabolite are 80 and 94% bound to albumin, respectively. Alvimopan is not a substrate for, nor an inducer or inhibitor of, the cytochrome P-450 (CYP) isoenzyme system; hepatic metabolism is not an important route of elimination for alvimopan. The drug is eliminated mainly through biliary secretion (65%) and, to a lesser extent (35%), in the urine.
The mean terminal-phase half-lives of alvimopan and its metabolite following multiple doses of the drug are 10-17 and 10-18 hours, respectively.
Generic name: alvimopan
Reference product & biosimilars
No reference, biosimilar or interchangeable associated with this drug.
Today’s intelligence on Entereg
Indications
The following indications are listed for Entereg:
- Postoperative Ileus
Dosing
Dosage of alvimopan, which is commercially available as the dihydrate, is calculated on the anhydrous basis.
To accelerate GI recovery in hospitalized patients following partial large or small bowel resection with primary anastomosis, the recommended adult dosage of alvimopan is 12 mg administered 30 minutes to 5 hours prior to surgery followed by 12 mg twice daily beginning the day after surgery and continuing for a maximum of 7 days or until discharge. Alvimopan is indicated for short-term (no more than 15 doses) use in hospitalized patients only. The drug should not be used for longer than 7 days following bowel resection.
No dosing information is available for this tab.
No dosing information is available for this tab.
No dosing information is available for this tab.
Drug interactions
There is no enhanced messaging for this drug.
There are no contraindication interactions for this drug.
There are no severe interactions for this drug.
There are no moderate interactions for this drug.
Contraindications
Patients who have taken opiates in therapeutic dosages for more than 7 consecutive days immediately prior to alvimopan administration.
There are no contraindication contraindications for this drug.
There are no severe contraindications for this drug.
There are no moderate contraindications for this drug.
Adverse reactions
Adverse effects reported in 3% or more of patients receiving alvimopan in clinical trials and more frequently (by a difference of at least one percentage point) with alvimopan than with placebo include constipation, hypokalemia, flatulence, dyspepsia, anemia, back pain, and urinary retention.
There are no severe adverse reactions for this drug.
There are no less severe adverse reactions for this drug.
Precautions
No enhanced messaging available.
Safety and efficacy not established in children younger than 18 years of age.
Category B. (See Users Guide.)
Alvimopan and its metabolite are distributed into milk in rats; it is unknown whether the drug or its metabolite is distributed into human milk. Alvimopan should be used with caution in nursing women.
Approximately 45% of patients enrolled in 5 clinical trials evaluating use of alvimopan for postoperative ileus were 65 years of age or older, and 18% were 75 years of age or older. Although no overall differences in efficacy or safety were observed between geriatric and younger patients and other clinical experience has not revealed any evidence of age-related differences, the possibility that some older patients may exhibit increased sensitivity to the drug cannot be ruled out.
ICD codes
No ICD codes are available for this drug.
Formulary status
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Last reviewed · Source: First Databank (FDB) drug data
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