Alvimopan: a peripheral acting µ-opioid-receptor antagonist used for the treatment of postoperative ileus

Opioid antagonists for prevention and treatment of opioid-induced gastrointestinal effects

PURPOSE OF REVIEW

The therapeutic action of opioid analgesics is compromised by peripheral adverse effects, among which constipation is the most disabling as laxatives often fail to provide satisfactory relief. This review highlights recent advances in the specific control of opioid-induced constipation by opioid receptor antagonists with limited systemic bioavailability or a peripherally restricted site of action.

RECENT FINDINGS

The specific management of opioid-induced bowel dysfunction is currently based on three drug entities: oral alvimopan for the shortening of postoperative ileus associated with opioid-induced pain control after bowel resection, subcutaneous methylnaltrexone for the reduction of opioid-induced constipation in patients with advanced illness, and a fixed combination of oral prolonged-release naloxone with prolonged-release oxycodone for the treatment of noncancer and cancer pain. All three drug entities have been shown to attenuate opioid-induced motor stasis in the gut with a favorable adverse effect profile, while the analgesic effect of opioids remains unabated.

SUMMARY

The availability of opioid receptor antagonists with restricted access to the central nervous system provides a novel opportunity to specifically control opioid-induced constipation and other peripheral adverse effects of opioid analgesics. Further studies are needed to evaluate the long-term efficacy, safety and cost-effectiveness of this approach.

Prokinetic Drugs in the Intensive Care Unit: Reviewing the Evidence

Delay in gastric emptying is common in the critically ill, and can lead to abdominal distension, diarrhoea or constipation, and vomiting, and may contribute to increased incidence of reflux and nosocomial infection. Prokinetic agents increase the rate of luminal transit as well as the force of contraction, and are commonly used in the intensive care unit. This article summarises the current state of knowledge about the use of prokinetics and explores potential agents which might be used in the future in this group of patients.