February 4, 2015
A new study recently published online in JAMA Internal Medicine “Cumulative Use of Strong Anticholinergics and Incident Dementia-A Prospective Cohort Study” has raised the bar on confirming the link between anticholinergic medication use by older adults and all-cause dementia. In an accompanying editorial, Noll L. Campbell PharmD of Purdue University College of Pharmacy called the study “the strongest evidence to date that anticholinergic drugs cause dementia”.
A team lead by Shelly L Gray PharmD, University of Washington, Seattle prospectively followed over 3400 participants over the age of 65 (mean age of 73) for 10 years, and assessed their use of strong anticholinergic medications and the incidence of all-cause dementia. (Strong anticholinergics are those that scored a “2 or 3” on an anticholinergic scale of 1-3.) They found about 20% of the participants were using one of the list of strong anticholinergic medications. They developed a process to characterize the medication use according to dosage, frequency and cumulative time on drug. The results showed that about 23% of the participants developed all-cause dementia, and of these, the vast majority was Alzheimer’s disease (80%).
Several things impressed us about the study. Some previous studies on the topic have low participant numbers, did not ascertain actual dose or duration of medications and/or had short follow-up periods. The study by Gray et al. seems to address these issues with a robust cohort size; specific criteria for determining dose/duration of medications, and a 10 year follow up study period. Essentially the findings collaborate what many clinicians believe…the more you use, the higher the dose, the longer the period of use…the higher the risk of dementia. We think the paper is an important read. You can use the following link to access the abstract, and obtain a full copy. http://archinte.jamanetwork.com/article.aspx?articleid=2091745
The study also brings us to strike once again some familiar chords. While Gray et al. focused on a strict method for characterizing anticholinergic medication use, the ‘list’ of offending medications were all ‘moderately strong’ and ‘strong’ anticholinergic medications. We know that many medications, prescription and OTC alike, have mild to moderate anticholinergic activity…and similarly when you stack all of those up into one medication regimen, particularly over time, you can get the same amount of cumulative harm as incurred by use of any one of the ‘strong’ ones. Even as marked a result as this study showed, the authors only focused on prescription claims data to identify anticholinergic medications use. Imagine if OTC medications had been included (loratadine (Claritin) anyone?), alone or in combination with prescribed medications as assessed via claims data.
So how do we reduce the utilization of anticholinergics in circumstances where dementia risk is a concern? Well, just scroll back a bit to a couple of our other blog postings “Is it Really Dementia? Or is it an Adverse Drug Event??” (10-29-2014) or “Taking a Closer Look at Benzodiazepine Use and Risk of Alzheimer’s disease in Older Adults” (9-14-2014). Like we said, ‘familiar chords’.
Claims are a good start for risk analysis, but let’s not just limit our risk analysis to strong prescribed anticholinergics. We need to go beyond claims or even medication orders and perform a comprehensive medication review that includes a structured patient interview which captures OTC and CAMs. We need to have a way to figure out the cumulative anticholinergic burden across ALL possible medications – Rx and OTC, and address the highest burden patients first. And lastly, we need a robust and agile way to communicate these findings to the rest of the health care team…not just keeping our findings in one silo, but letting all team members benefit from the knowledge of risk identified by one team member.
Joseph Gruber, RPh, CGP, FASCP: Chief Clinical Officer, ActualMeds Corporation. Past President, American Society of Consultant Pharmacists. @jgactualmeds