by: Tom Jeter, BS Pharm., R.Ph.
An analysis conducted over the last year is raising some concern over a common drug used to treat overactive bladder that is being highly prescribed in the US. The analysis has shown that a drug, oxybutynin, when taken orally, is consistently linked with cognitive impairment and dementia in the elderly. Oxybutynin, is prescribed in more than a quarter of cases of overactive bladder (27.3%), even though other medications are available that would be just as effective without this side effect.
Overactive bladder (OAB) is extremely common in males and females over 65. Initial treatment is normally through bladder training programs which help modify behavior, which can then be followed by first-line medical treatment such as antimuscarinic medications, including oxybutynin. Antimuscarinic drugs are compounds that are synthetic produced, originally formulated from mushrooms, which block the activity of the muscarinic acetylcholine receptor. They have several uses, including control of OAB. Oxybutynin is the least expensive antimuscarinic used for OAB, and so tends to be the drug of choice for health care plans such as Medicare. However, a body of evidence has shown that oxybutynin is linked to greater cognitive decline in the elderly.
An international group of clinicians, led by Dr Daniel Pucheril (Vattikuti Urology Institute, Henry Ford Hospital, Detroit), looked at evidence from the National Ambulatory Medical Care Survey, where 1,968 patients had received antimuscarinic medications. They found that oxybutynin was prescribed to 27.3% of patients aged over 65 receiving a new antimuscarinic prescription for OAB. Additionally, despite the United States Food and Drug Administration recommendation that patients starting oxybutynin be closely monitored for adverse central nervous system side effects, the authors found that only 9% of elderly persons received a neurologic exam at the time of drug prescription.
Around 16% of US adults suffer from overactive bladder, which translates into tens of millions of sufferers in the US.
According to Dr Pucheril, “We looked at a representative sample, but when you extrapolate to the US population the figures are huge. We estimate that over the six years of our analysis, 47 million individuals in the USA were taking various types of antimuscarinic drugs for OAB, with around 55% of new prescriptions going to the over 65’s. After lifestyle modifications, antimuscarinic medications constitute the most common first line therapies. In the United States, the majority of elderly persons are insured by Medicare. Medicare insurance plans have often had tiered medication formularies to minimize drug expenses. Oxybutynin is the least expensive antimuscarinic drug available, but its pharmacologic properties may cause significant cognitive side effects in elderly persons. Despite evidence of these side effects, physicians are not commonly checking for cognitive effects in those using these medications.”
Dr Pucheril continued, “We’re not saying that everyone should change from oxybutynin to another drug— it still has its uses and coming off the drug without medical supervision is not recommended. Nevertheless, doctors need to look closely at the levels of prescribing. More than anything else, the funding bodies have to make it easier for doctors to prescribe newer antimuscarinics which are much less likely to cause cognitive dysfunction.”
In our geriatric population where our goal is to help maintain their activity of daily living as much as possible, we need to consider the above evidence as we care plan for residents that have OAB and consider alternatives, if prescribed Oxybutynin. For recommendations of alternatives to Oxybutynin, please contact your Gayco Consultant Pharmacist.
1) European Association of Urology: https://www.sciencedaily.com/releases/2017/03/170327083445.htm
2) American Geriatrics Society 2015 updated Beers Criteria for potentially inappropriate medication use in older adults: https://www.guideline.gov/summaries/summary/49933