Opioid/naloxone prolonged release combinations for opioid induced constipation

Abstract

I read with great interest the recent article by Chen et al in a recent issue of your esteemed journal. The article is highly thought provoking. One emerging therapeutic alternative for opioid induced constipation is the emergence of opioid/naloxone prolonged release combinations. For instance, naloxone when administered in a 1:2 ratio with oxycodone reverses the inhibitory effect of oxycodone on the gastrointestinal tract. The advantage of oxycodone/naloxone prolonged release (OXN) is that while its anti-nociceptive efficacy is equivalent to that of oxycodone prolonged release (OXC), it significantly decreases the “Bowel Function Index” thereby ameliorating symptoms of opioid induced constipation to a large extent. Schutter et al in a recent study have reported a decrease in the bowel function index from 38.2 to 15.1. Similarly, Löwenstein et al in another recent study have reported that following a month of therapy, complete spontaneous bowel movements per week is increased from one in OXC therapy to three in OXN therapy.

Key Words: Opiod naloxone, Cancer, Morphine, Carcinogenesis

TO THE EDITOR

I read with great interest the article by Chen et al[1] in a recent issue of your esteemed journal. The article is highly thought provoking. One emerging therapeutic alternative for opioid induced constipation is the emergence of opioid/naloxone prolonged release combinations.

For instance, naloxone when administered in a 1:2 ratio with oxycodone reverses the inhibitory effect of oxycodone on the gastrointestinal tract[2]. The advantage of oxycodone/naloxone prolonged release (OXN) is that while its anti-nociceptive efficacy is equivalent to that of oxycodone prolonged release (OXC), it significantly decreases the “Bowel Function Index” thereby ameliorating symptoms of opioid induced constipation to a large extent. Schutter et al[3] in a recent study have reported a decrease in the bowel function index from 38.2 to 15.1. Similarly, Löwenstein et al[4] in another recent study have reported that following a month of therapy, complete spontaneous bowel movements per week is increased from one in OXC therapy to three in OXN therapy.

In fact, the colonic transit time is reduced by almost two hours with OXN 20/10 mg combination therapy[5]. This is further affirmed by the fact that in patients receiving OXN therapy the mean laxative use is decreased by almost 20% while the stool consistency as measured by the “Bristol Stool Form Scale” is improved from type 2 to type 5[6,7].

In addition, in a recent study, the quality of life was accentuated by 47% following OXN therapy for management of chronic severe neuropathic pain[8]. Similarly, a low mean Brief Pain Inventory Short Form “sleep interference” score is maintained with OXN therapy and is comparable to OXC therapy[9].

Clearly, OXN therapy is highly effective in mitigating the symptoms of opioid induced constipation and provides a safe and efficacious alternative to methylnaltrexone.