Treating elderly patients with depression can be difficult, particularly if you choose to treat their depression with medication. The prevalence and severity of adverse drug reactions are higher in patients above the age of 65 than the rest of the general population. In fact, medication-related adverse events are thought to cause between 10% and 30% of all hospital admissions in older patients. Further, a study found that 88% of adverse drug reactions in elderly patients could have been avoided.
These adverse drug events are costly. It has been reported that for patients at nursing facilities, every dollar spent on medications results in $1.33 subsequently required for treatment of drug related morbidity and mortality.
There are several reasons why adverse events are so common in the elderly:
- Comorbid diseases and conditions– many patients are taking multiple medications to manage several health (and mental health) issues; additionally, comorbidities are often accompanied by renal or hepatic impairment
- Drug-disease interactions– taking a medication may cause adverse effects due to another co-existing disease
- Conditions such as obesity or ascites– these conditions may alter the volume of distribution of different medications (in other words, they’re changing how well the medication can be absorbed into tissue)
- Dementia– the presence of dementia may increase sensitivity or induce paradoxical reactions to CNS active agents
How to Manage Polypharmacy
The factor most consistently associated with side effects in the elderly is polypharmacy.
The National Center for Health Statistics (chart below) shows the percentage of polypharmacy by population group over a 30-day span. It shows that nearly 40% of the elderly take five or more different medications.
Multiple medications can cloud the ability of healthcare providers to correctly identify the drug culprits potentially causing the reactions.
Physiologic Changes Impact Medication Response
Another major contributing factor to the increased risk of side effects in elderly patients is the pharmacokinetic and pharmacodynamic changes that occur naturally as the body ages. Pharmacokinetics is how the body affects the drug, while pharmacodynamics is how the drug affects the body.
One tool that can help healthcare providers navigate these changes in elderly patients is pharmacogenomics, which can give insight into optimal medication selection based on a patient’s unique genetic composition. The GeneSight test can help healthcare providers find effective drug therapies, while minimizing the risk of preventable adverse reactions.
On average, patients who were 65 and over and had clinicians who made decisions congruent with the GeneSight Psychotropic test:
- Were on one less CNS (central nervous system) medication per year than those with clinicians whose decisions were incongruent1
- Were on two less medications overall per year than those with clinicians whose decisions were incongruent1
And for patients with traditional Medicare, their financial responsibility will be zero for the GeneSight Psychotropic test when ordered by a psychiatrist contemplating a change in medication for patients suffering from moderate to severe depression who have failed on one or more neuropsychiatric medications.
Treating mental health disorders in the elderly is challenging at best. There’s a lot to consider when it comes to changes that occur naturally with age. There are tools available to help. Learn more on our website’s “For Clinicians” page, and watch our Chalk Talk series on the topic at our YouTube channel.
- Mayhew, M. et al. Combinatorial pharmacogenomics reduces polypharmacy and medication cost in elderly patients with anxiety and/or depression. Poster session presented at: American Association for Geriatric Psychiatry Annual Meeting; 2017 March 24-27; Dallas, TX.