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ISSUE 1 FEBRUARY
Letters to the Editor

Opioids and constipation

  • Barry Werth, Michael McDonough

The Editorial Executive Committee welcomes letters, which should be less than 250 words. Before a decision to publish is made, letters which refer to a published article may be sent to the author for a response. Any letter may be sent to an expert for comment. When letters are published, they are usually accompanied in the same issue by their responses or comments. The Committee screens out discourteous, inaccurate or libellous statements. The letters are sub-edited before publication. Authors are required to declare any conflicts of interest. The Committee's decision on publication is final.

 

Letter to the Editor

Editor, - I refer to the article by Dr McDonough (Aust Prescr 2012;35:20-4). I was interested to see in Table 1 that he recommends non-osmotic laxatives to treat chronic constipation and I wondered why this recommendation is made.

Barry Werth
Faculty of Pharmacy
The University of Sydney

 

Author's comments

Michael McDonough, author of the article, comments:

Thank you for this important question concerning constipation. The recommendation pertains to chronic opioid-related constipation, which is often difficult to manage because of opioid-induced hypomotility. While the use of stimulant laxatives has been suggested,1 the possibility of longer-term adverse consequences (for example melanosis coli) probably should limit their use, if not exclude them. Regarding the use of bulking agents and osmotic and non-osmotic products, there appears to be limited evidence supporting which is the safest and most effective for long-term use.2 However in my clinical experience, osmotic products can cause problems – for example dehydration and electrolyte disturbance. Many patients experience occasional nausea and vomiting, and are often taking multiple medications.

I therefore recommend the strategy of least risk, that is fluids, bulking agents and non-osmotic products like stool softeners in conjunction with diet, exercise and bowel hygiene counselling. If such management fails, referral to a specialist should be considered. That process may include a review of why such commonly recommended management has apparently failed and then starting a trial of osmotic products with ongoing monitoring of safety and efficacy.

 

References

  1. Goodheart CR, Leavitt SB. Managing opioid-induced constipation in ambulatory-care patients. Pain Treatment Topics. 2006. http://pain-topics.org/pdf/Managing_Opioid-Induced_Constipation.pdf .
  2. Selby W, Corte C. Managing constipation in adults. Aust Prescr 2010;33:116-9 .

Barry Werth

Faculty of Pharmacy, The University of Sydney

Michael McDonough