In particular, between 40% and 95% of patients develop opioid-induced constipation (OIC). Therefore, there is a consensus that patients should commence laxatives at the start of opioid therapy and continue throughout treatment. Nevertheless, laxatives are not routinely coprescribed with opioids.
This is a significant deficiency that needs to be addressed in the future studies. Although the safety and efficacy of opioid antagonists have been proven in several studies, none of the previous studies has established an improvement in quality of life with increased passage of bowel movements.
Therefore, there is a consensus that patients should commence laxatives at the start of opioid therapy and continue throughout treatment. The failure of lifestyle modification and laxatives to treat adequay many cases of OIC led to the concurrent use of peripherally acting opioid antagonists (such as methylnaltrexone bromide and naloxone) to reduce the incidence of gastrointestinal adverse events without compromising analgesia.
The following paragraphs address the conventional management of opioid-induced constipation, including Currently, efforts are underway to generate more comprehensive algorithms to guide switching in opioid-tolerant patients.
Cross-tolerance varies among opioids, an issue that may complicate the calculation of the optimal initial dose ( 45 ). Because the potency of opioids varies widely ( 44 ), when rotating opioids providers should consult equianalgesic dose tables to reduce the risks of over- or underdosing. Opioids vary in their propensity to cause constipation; likewise, individuals vary in terms of opioid dose required for pain relief and their liability for side effects.
The efficacy and safety of methylnaltrexone in the treatment of opioid-induced constipation (OIC) have been evaluated in two multicentre, randomised, double-blind, placebo-controlled phase III trials involving adults with advanced illness (life expectancy of 1–6 months) who were receiving palliative care.9 ,10 The majority.
The patient will continue to receive the study drug at the same time on a daily basis, until the patient has been free of opioids for 24 hours or at 28 days. Rescue therapy.
The exclusion criteria are as follows:
10 Methylnaltrexone significantly improved the laxation rate within 4 hours of dosing (62% for 0.15 mg/kg and 58% for 0.30 mg/kg vs 14% for placebo (p<0.0001 for each dose vs placebo)). The median time to laxation was shorter in the group administered methylnaltrexone (70 and 45 min for the 0.15 and 0.30 mg/kg groups, respectively, compared with placebo (>24 hours) (p<0.0001 for each dose vs placebo)).
The treatment of chronic pain, whether of cancer or noncancer origin, frequently involves the use of opioids. It has been estimated that up to 90% of patients with chronic pain receive opioids.1 Interestingly, in spite of being used for millenia, opioids have not seemed to garner the attention and investigation.
Once it is established that no other cause exists, that the constipation started after the opioids were initiated, then specific questions concerning bowel movements should be asked. The clinical history is the key: What was the patient’s previous bowel pattern prior to starting opioids? What is the current pattern now that the patient is taking opioids? These two questions will help diagnose as well as provide goals for treatment. A treatment goal of a daily bowel movement would not be appropriate in a patient whose normal bowel pattern is every 2 to 3 days.
Proposed algorithm for the treatment of opioid induced bowel dysfunction, especially constipation. The arrows indicate a failure of the first recommendation and thus continuation to next step. Treatment goals are to establish regular bowel function and eliminate upper gastrointestinal symptoms, improve quality of life and.
Conventional laxatives have limited effects on OIC and may cause adverse effects.
Pain management and quality of life in chronic pain patients is reduced by OIC.
Opioid-induced constipation (OIC) is one of its many symptoms and probably the most prevalent. Opioid-induced bowel dysfunction (OIBD) is an increasing problem due to the common use of opioids for pain worldwide. It manifests with different symptoms, such as dry mouth, gastro-oesophageal reflux, vomiting, bloating, abdominal pain, anorexia, hard stools, constipation and incomplete evacuation.