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- Page navigation anchor for RE: nortriptyline safer than amitriptyline?RE: nortriptyline safer than amitriptyline?
The Canadian Pain Society’s recent consensus statement on chronic neuropathic pain reads: “When prescribing TCAs, secondary amines (nortriptyline, desipramine) are usually better tolerated in terms of sedation, postural hypotension, and anticholinergic effects when compared with tertiary amines (amitriptyline and imipramine) with comparable analgesic efficacy” [1].
The reference cited for this statement by the Canadian Pain Society is a review published in 1996 [2]. We combed through this review and could not find any evidence to substantiate this claim. On the matter of adverse events, it finds that “The two reports with dichotomous data on comparisons of different tricyclics did not show any significant difference” [2].
The 2015 Cochrane systematic review of nortriptyline for neuropathic pain reiterates the general view “Nortriptyline is sometimes preferred to amitriptyline because it reputedly has a lower incidence of associated adverse effects” [3]. They subsequently describe the state of adverse event reporting in nortriptyline trials as “inconsistent and fragmented” [3]. However, in a contemporary neuropathic pain trial involving randomization to nortriptyline, dry mouth (a classic anticholinergic harm) seems to us remarkably common: affecting almost 60% of participants receiving the drug [4].
This leads us to a couple of questions:
1. If nortriptyline is the principal active metabolite of amitriptyline [3], is it likely that nortriptylin...
Show MoreCompeting Interests: None declared. - Page navigation anchor for RE: Pharmacologic management of chronic neuropathic painRE: Pharmacologic management of chronic neuropathic pain
The review of the Canadian Pain Society (CPS) consensus statement on the pharmacologic management of chronic neuropathic pain in the November 2017 issue of Canadian Family Physician (1) does a good job of summarizing the recommendations in the guidelines (2). However, aside from a statement that the Neuropathic Pain Special Interest Group of the CPS “is a multidisciplinary group of individuals with research and clinical expertise relevant to the pathophysiology and management of” neuropathic pain, the review is silent about the composition of the committee that drafted the guidelines. This omission is important because the committee’s composition was contrary to at least four of the recommendations from the Institute of Medicine (IOM) in its 2011 report on the creation of guidelines (3).
The IOM recommended that members with conflicts of interest (COI) should represent not more than a minority of the guideline development group (GDG), whereas 13 of the 18 committee members had financial COI with various pharmaceutical companies. The IOM recommended that the chair should not be a person with COI. Dr. Moulin who is the first author, and presumably the committee chair, reported COI with five pharmaceutical companies. The IOM recommended that the GDG should include a current or former patient, and a patient advocate or patient/consumer organization representative but none appears to have been involved in the creation of this guideline. Finally, the IOM recommended that...
Show MoreCompeting Interests: In 2015-2017 Joel Lexchin received payment from two non-profit organizations for being a consultant on a project looking at indication based prescribing and a second looking at which drugs should be distributed free of charge by general practitioners. In 2015 he received payment from a for-profit organization for being on a panel that discussed expanding drug insurance in Canada. He is on the Foundation Board of Health Action International.