More Rules for Improving Pharmacotherapy in Older Adults
More Rules for Improving Pharmacotherapy in Older Adults
It has been estimated that 90% of all individuals 65 years or older take at least 1 medication per week, 40% use ≥5, and 12% use ≥10/week. Because of the sheer number of medications that some individuals receive, the risk for drug–drug interactions is extremely high. Drug–drug interactions can be categorized as either pharmacodynamic or pharmacokinetic interactions.
Pharmacodynamic interactions occur when prescribing drugs with synergistic actions. These interactions are common and can occur when a patient has more than one healthcare provider or the prescriber does not thoroughly understand the pharmacology of the drugs being prescribed. This can be confusing and dangerous, especially when drugs from completely different drug classes are prescribed. The presentation in patients can be insidious as the drugs are added one on top of the other ("drug stacking"), until the synergistic effects merge and the syndrome presents itself; thus, medication reviews by pharmacology experts should be recommended for patients who are taking several different medications. Two specific examples of this problem are presented in Table 1
Because of the physiologic changes associated with aging, these patients are at greater risk for drug–drug interactions. Hepatic metabolism may be significantly altered for some drugs. The reasons for various drug–drug interactions in older adult patients include changes in drug absorption and distribution, reduced hepatic clearance and reduced renal function, polypharmacy, and the high number of comorbidities in these individuals.
Drug–drug interactions cannot always be avoided. Practitioners must be able to anticipate these interactions and create a monitoring plan to minimize the risk to the patient. Ways to mitigate these interactions in older adults, beyond those mentioned earlier in the article, include close monitoring of drugs with a narrow therapeutic range or index ( Table 2 ) and knowledge of the common "inducer" and "inhibitor" drugs ( Table 3 ).
Another type of interaction prevalent in the geriatric population is drug–disease interactions, wherein a particular drug may worsen a specific medical condition ( Table 4 ). Understanding the pharmacologic profile of each drug prescribed to an older adult patient can reduce the incidence of these types of interactions.
Other interaction types occur in older people, including drug–food interactions and drug–nutrient interactions. Practitioners must be observant with all drugs prescribed to avoid these common interaction issues.
Rule 7: Identify, Anticipate, and Monitor Potential Drug Interactions Before They Become a Problem
It has been estimated that 90% of all individuals 65 years or older take at least 1 medication per week, 40% use ≥5, and 12% use ≥10/week. Because of the sheer number of medications that some individuals receive, the risk for drug–drug interactions is extremely high. Drug–drug interactions can be categorized as either pharmacodynamic or pharmacokinetic interactions.
Pharmacodynamic Interactions
Pharmacodynamic interactions occur when prescribing drugs with synergistic actions. These interactions are common and can occur when a patient has more than one healthcare provider or the prescriber does not thoroughly understand the pharmacology of the drugs being prescribed. This can be confusing and dangerous, especially when drugs from completely different drug classes are prescribed. The presentation in patients can be insidious as the drugs are added one on top of the other ("drug stacking"), until the synergistic effects merge and the syndrome presents itself; thus, medication reviews by pharmacology experts should be recommended for patients who are taking several different medications. Two specific examples of this problem are presented in Table 1
Pharmacokinetic Interactions
Because of the physiologic changes associated with aging, these patients are at greater risk for drug–drug interactions. Hepatic metabolism may be significantly altered for some drugs. The reasons for various drug–drug interactions in older adult patients include changes in drug absorption and distribution, reduced hepatic clearance and reduced renal function, polypharmacy, and the high number of comorbidities in these individuals.
Drug–drug interactions cannot always be avoided. Practitioners must be able to anticipate these interactions and create a monitoring plan to minimize the risk to the patient. Ways to mitigate these interactions in older adults, beyond those mentioned earlier in the article, include close monitoring of drugs with a narrow therapeutic range or index ( Table 2 ) and knowledge of the common "inducer" and "inhibitor" drugs ( Table 3 ).
Another type of interaction prevalent in the geriatric population is drug–disease interactions, wherein a particular drug may worsen a specific medical condition ( Table 4 ). Understanding the pharmacologic profile of each drug prescribed to an older adult patient can reduce the incidence of these types of interactions.
Other interaction types occur in older people, including drug–food interactions and drug–nutrient interactions. Practitioners must be observant with all drugs prescribed to avoid these common interaction issues.