4 Factors That Influence Proper Medication Use

Your patients may not realize that the effectiveness of their medications is largely within their control.

According to the Institute of Medicine, nearly 50% of US adults have trouble understanding their medications’ instructions, so pharmacists should engage patients in interactive conversations in order to ensure that they do not stop taking them.

Here are some common reasons why a patient’s medications may not be working properly:

1. Patients are not taking medications exactly as directed.

While most Americans recognize the importance of taking prescribed medication as directed, those who skip or forget doses are less likely to understand the health consequences of nonadherence.

Nearly three-quarters of Americans report that they do not always take their medication as directed, despite knowing that they should. This problem causes more than one-third of medicine-related hospitalizations and nearly 125,000 deaths in the United States each year, and it adds $290 billion in avoidable costs to the health care system annually.

Beyond general adherence issues, medications can also sometimes interact with other prescription drugs, vitamins, or supplements. Pharmacists should encourage patients to read labels in order to avoid this issue.

2. A patient’s diet may be interfering with medications.

There is a dynamic relationship between the foods we eat and the medications we take. Many foods can substantially interfere with therapeutic goals and change the absorption of a medication into the bloodstream.

For example, high-fat, high-cholesterol foods can sharply reduce the effect of angiotensin-converting enzyme inhibitors like enalapril, as well as statins and some other cholesterol medications.

However, not all negative interactions between medications and diet stem from poor nutrition. Patients may not recognize that otherwise healthy foods can have severe consequences when they’re mixed with certain drugs.

As medication experts, pharmacists should clearly communicate the risk of possible food-drug interactions for both prescription and OTC medications.

Examples of potentially dangerous food-drug interactions include:

• Calcium-rich foods + antibiotics
• Pickled, cured, and fermented foods + monoamine oxidase inhibitors
• Vitamin K-rich foods + warfarin
• Grapefruit and grapefruit juice + statins

3. A patient’s lifestyle habits may be interfering with medications.

Negative lifestyle factors such as excess weight, smoking, physical inactivity, and binge drinking can affect the health of patients taking certain medications.

With smoking, for instance, the most consistently observed effect of cigarettes on drug metabolism is an increase in the clearance of drugs that are substrates of CYP1A2, which include clozapine, fluvoxamine, olanzapine, tacrine, and theophylline.

Meanwhile, alcohol intake can have both short- and long-term effects in patients with diabetes, including interactions with diabetes medications and worsening of preexisting complications. For example, mixing insulin and oral hypoglycemic with alcohol may increase the risk of hypoglycemic reactions, while mixing metformin with chronic alcohol use may predispose a patient to lactic acidosis.

4. A patient may have comorbid conditions.

Approximately 50% of all patients with chronic conditions have comorbidities.

Because current health care practice focuses on diagnosing and prescribing, the need to taper, reduce, or discontinue inappropriate medication therapy receives relatively little attention.

Thomas R. Clark, RPh, MHS, CGP, executive director of the Commission for Certification in Geriatric Pharmacy, told Pharmacy Times that failure to reconcile medications and properly manage comorbid chronic diseases may affect elderly patients in particular.

He noted that older adults often fall victim to the “prescribing cascade” that occurs when “new symptoms end up being treating with a new drug instead of discontinuing or changing the offending drug that is causing the symptom.”

To avoid polypharmacy, pharmacists must review drug regimens carefully and screen for drug interactions, dosing irregularities, and other blatant red flags.