Medicine & Research

Cognitive Impairment – When Medications Are the Problem

By Ellen Whipple, BS, Pharm.D. MSF Medical Advisor


Estimates of the number of people with MS who suffer from some degree of cognitive impairment vary. However, cognitive impairment is more common in people with progressive disease compared to patients with relapsing-remitting disease. Cognitive impairment is not absent, however, from patients with early disease. Dr. Ben Thrower, medical director of the MS Institute at the Shepherd Center, said, “cognitive impairment can be observed in patients with both clinically isolated syndrome and radiographically isolated syndrome and up to 20 percent of patients with benign MS experience cognitive impairment.” Cognitive impairment tends to be more severe in patients with a longer duration of disease and those having signs of irreversible neurological deficit.
 
There are currently no Food and Drug Administration products approved to treat MS-related cognitive impairment. This is because many factors can cause or exacerbate cognitive impairment in patients with MS. 
 
According to Dr. Thrower, medications are sometimes the offending agent and can contribute or worsen cognitive impairment. Dr. Thrower said, “Tweaking or changing medication regimens can sometimes improve the symptoms of cognitive impairment.”
 
Anticholinergic medications – perhaps the most common cause of cognitive impairment
 
Anticholinergic medications are one of the most common causes of acute and chronic cognitive impairment in patients with and without MS. Anticholinergic medications are a class of drugs that block the action of the neurotransmitter acetylcholine in the brain. They are used to treat many diseases including asthma, incontinence, gastrointestinal cramps, and muscle spasms. They can also be prescribed for depression and sleep disorders.
 
Anticholinergic medications frequently cause confusion, memory loss, worsening of mental function, and other cognitive effects. Elderly patients are generally more susceptible to the cognitive effects of anticholinergic medications compared to younger adults.
 
Examples of anticholinergic medications include:
  • Trihexyphenidyl (Artane)
  • Benztropine mesylate (Cogentin)
  • Flavoxate (Urispas)
  • Oxybutynin (Ditropan, Oxytrol)
  • Scopolamine
  • Hyoscyamine (Levsinex)
  • Tolterodine (Detrol)
  • Belladonna alkaloids
  • Fesoterodine (Toviaz)
  • Solifenacin (VESIcare)
  • Darifenacin (Enablex)
  • Propantheline (Pro-Banthine)
 Any Medication That Crosses the Blood-Brain Barrier
 
Any medication that crosses the blood-brain barrier has the potential to decrease cognition. Compared to young people, elderly people are more likely to develop cognitive impairment associated with medications. Psychoactive drugs, antidepressants, and anticonvulsants can cause acute states of confusion. In addition, nonpsychoactive drugs – such as histamine H2 receptor antagonists, (acid reducers) cardiac medications, and antibiotics – may cause acute and chronic cognitive impairments.

It is important to note that these medications do not cause cognitive impairment in all persons. There can be tremendous differences between patients. Generally, those susceptible to cognitive impairment with one medication are more likely to experience it with other medications.
 
Advice from the Pharmacist
 
Those experiencing cognition challenges should be encouraged to speak with their pharmacists. In many cases, medication regimens can be tweaked to minimize cognitive problems. In other cases, medications can be administered at times of the day to minimize cognitive issues (e.g., before bedtime).
 
Pharmacists may also be able to simplify treatment regimens so that confusion is avoided. This can be accomplished by suggesting medication(s) that can be given once per day rather than multiple times per day, suggesting medication(s) that can be given less frequently, and suggesting medication(s) that can be used to treat more than one symptomatic problem.
 
Those individuals who are experiencing cognitive impairment (or patients taking multiple medications multiple times per day) should consider having medications blister packed or use one of the weekly devices to dispense medications. There are also apps available on Google and at the Apple Store that remind you when to take medications.
 
Ellen Whipple, Pharm.D has been a medical advisor with the MSF since 2002. She is a clinical pharmacist employed as a medical affairs specialist, as well as an assistant clinical professor at the University of Georgia. She received her Doctorate of Pharmacy degree from the University of Georgia College of Pharmacy in 1994 and was later employed at the Shepherd Center and Children’s Healthcare of Atlanta. Ellen is an active member of the Georgia Society of Health System Pharmacists. She has also served on the Pharmacy Advisory Committee for the Department of Community and Health.