Chapter 47: Pharmacotherapy Principles for the Family Physician

INTRODUCTION

Medication therapy is an integral element of healthcare interventions. In 2011, >4 billion prescriptions were dispensed in the United States. Medication use is often supported by “hard science” and evidence; clinical practice often shifts to the “soft science” of medicine, trying to understand patients, their histories, personalities, medication adherence, and a way to provide the best possible care.

Of the billions of prescriptions filled, it is estimated that half are taken improperly. Achieving a balance between “hard” and “soft” sciences—by providing evidence-based medication therapy that patients will adhere to—becomes paramount. This chapter explores patient adherence; provider’s considerations such as evidence, pharmacokinetics/pharmacodynamics, and safety; and healthcare system factors such as formulary systems/resources.

TAKING A MEDICATION HISTORY

Discrepancies among documented medication therapy records and actual patient use of medications are common and occur with all classes of medications. Therefore, the first step for the provider in determining optimal medication therapy is to understand what medications patients are actually taking and how they are taking them. The physician must also inquire in a nonjudgmental manner whether patients are taking any over-the-counter (OTC) medications, herbal, or vitamin products. Over 17% of the population takes herbal supplements on a yearly basis, but only 45% of these patients report this to their physician. Table 47-1 lists five concise steps to a medication review. To obtain an accurate medication history, the physician should start by asking open-ended questions; for example, “What medications are you taking?” This approach avoids the common mistake of assuming the patient is taking all their medications as prescribed. Although conducting an open-ended medication history may take more time up front, it may ultimately prevent over- or underprescribing and may also improve patient relationships. Polypharmacy is defined as the concurrent use of multiple medications or the prescribing of more medications than are clinically indicated. Polypharmacy can be minimized by a thorough medication regimen review.