Dementia medication interactions

Memory care providers have been using the same arsenal of drugs to treat dementia symptoms for years. But the geriatric population has changed a lot in the past decade, calling for deeper medication management strategies, says Joseph Marek, RPh, CGP, director of pharmacy services at CommuniCare Health Services and president of the American Society of Consultant Pharmacists, in an educational session at the Fall Memory Care Forum in San Diego.

“Our skilled nursing patients are older than they used to be,” Marek says. “We’re now treating the oldest old, which enhances problems with liver and kidney function and can exacerbate the length and strength of a medication’s effects and how it is absorbed.”

The Beers Criteria lists about 200 drugs that should be avoided for residents with dementia because they have a high potential of interaction or adverse events, they carry risks with little support of benefits, or they need to be adjusted for people who have high risk of poor renal function. But with a limited number of dementia drug choices, clinical staff needs to place higher emphasis on monitoring residents for adverse events. For example, “If you’re giving Aricept, you need to be monitoring for bradycardia,” Marek says. “I’ve even seen some facilities get cited because they weren’t monitoring for that. The same goes for drugs like Namenda that call for renal dose adjustment.”

Specific complications arise with dementia medications, which often interact with anticholinergics, including antihistamines, antispasmodics and antiemetics. “Aricept and Benadryl are opposed pharmacologically and may cancel each other out,” Marek warns. Drugs like diphenhydramine have been available over the counter for so long, people often self-administer them with little thought to medication interactions. Yet this drug class carries a 31 percent increased risk of death, Marek explains. “If someone is on an anticholinergic, they may have been on it for years. Talk with them about the risks.” 

The presence of dementia also can mask reactions to other medications that require diligent monitoring. “Coumadin/warfarin is one of the most dangerous drugs out there,” Marek says, noting that the drug’s effects on the blood can swing wildly even on a daily basis. “Someone at your facility should be monitoring medication management, and it needs to be based on patient-specific data. You need to be reviewing patient-specific information, doing frequent medication reviews and facilitating communication between the SNF, the hospital and the primary care physician.”

The prescribing cascade

The scenario is familiar to most caregivers: A resident with dementia begins to lose weight, so the physician prescribes an antidepressant. Then the resident experiences sudden sleep problems, so caregivers add a sleep aid. Now the resident shows signs of confusion and sluggish gait, skyrocketing the risk of falling. Meanwhile, the combination of Aricept and Benadryl has resulted in the side-effect of incontinence, leaving the resident open to urinary tract infections that will require antibiotics.

Skilled nursing caregivers can play an important role in helping residents avoid the “medication cascade.” Documenting and reporting side effects—and flagging symptoms that are new—can help prescribers and pharmacy consultants understand how medications are combining in a specific resident. “Instead of adding another drug, let’s look at eliminating some of the medications. Don’t add another drug until you rule out every other option.”  

One of the most dangerous situations—and one of the easiest to correct—is the “whenever, forever” prescription. Prescribers need better information on how long an as-needed medication is meant to be used, and residents need to understand that unnecessary medications can include everything from antipsychotics to antihistamines. New rules are already under way on prescribing habits for sedatives and antibiotics that will require hands-on evaluation by a clinician every 14 days to authorize a reorder, Marek says.

“Just because a resident is on a med doesn’t mean it’s going to work,” Marek says. “Medications need to be integrated into the care plan. What’s the goal? How long is the med expected to be part of the plan? How often will it be evaluated?” Electronic health record (EHR) alerts can help, but only if the medical record is completely up to date, he adds. “EHRs are great, but don’t get lazy on process. Review meds every time there’s an interaction with the resident. They may have forgotten to say they’re taking a new med or that they are no longer taking one, but it’s still stuck in the record.”

Training caregivers to document all medication instructions and administration durations is a proactive habit, even for over-the-counter medications. “Educate your prescribers to put an expiration date on all PRN orders,” Marek warns. “Sooner or later it’s going to be a rule.”

Topics: Alzheimer's/Dementia , Articles