Page 1160 - Basic _ Clinical Pharmacology ( PDFDrive )

65 Rational Prescribing &
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Prescription Writing

Paul W. Lofholm, PharmD, &
Bertram G. Katzung, MD, PhD

Once a patient with a clinical problem has been evaluated and a For example, increasing knowledge about the mediators of
diagnosis has been reached, the practitioner can often select from a inflammation makes possible more effective use of nonsteroidal
variety of therapeutic approaches. Medication, surgery, psychiatric anti-inflammatory drugs (NSAIDs) and other agents used in
treatment, radiation, physical therapy, health education, counsel- rheumatoid arthritis. The patient should be provided with the
ing, further consultation (second opinions), and no therapy are appropriate level and amount of information about the patho-
some of the options available. Of these options, drug therapy is physiology. Many pharmacies, websites, and disease-oriented
by far the one most frequently chosen. In most cases, this requires public and private agencies (eg, Arthritis Foundation, Ameri-
the writing of a prescription. A written prescription is the pre- can Heart Association, American Cancer Society, etc) provide
scriber’s order to prepare or dispense a specific treatment—usually information sheets suitable for patients.
medication—for a specific patient. When a patient comes for an 3. Select a specific therapeutic objective: A therapeutic objective
office visit, the physician or other authorized health professional should be chosen for each of the pathophysiologic processes
prescribes medications 67% of the time, and an average of one defined in the preceding step. In a patient with rheumatoid
prescription is written per office visit because more than one pre- arthritis, relief of pain by reduction of the inflammatory pro-
scription may be written at a single visit. cess is one of the major therapeutic goals that identifies the
In this chapter, a plan for prescribing is presented. The physi- drug groups that should be considered. Arresting the course of
cal form of the prescription, common prescribing errors, and legal the disease process in rheumatoid arthritis is a different thera-
requirements that govern various features of the prescribing pro- peutic goal, which might lead to consideration of additional
cess are then discussed. Finally, some of the social and economic drug groups and prescriptions.
factors involved in prescribing and drug use are described. 4. Select a drug of choice: One or more drug groups will be sug-
gested by each of the therapeutic goals specified in the preced-
RATIONAL PRESCRIBING ing step. Selection of a drug of choice from among these groups
follows from a consideration of the specific characteristics of
Like any other process in health care, writing a prescription should the patient and the clinical presentation, a selection process
be based on a series of rational steps as follows: that has been emphasized as part of “precision medicine.” For
certain drugs, characteristics such as age, other diseases, and
1. Make a specific diagnosis: Prescriptions based merely on a other drugs being taken (because of the risk of duplicative
desire to satisfy the patient’s psychological need for some type of therapy or drug-drug interactions) are extremely important in
therapy are often unsatisfactory and may result in adverse effects. determining the most suitable drug for management of the
A specific diagnosis, even if it is tentative, is required to move to present complaint. As the tools of precision medicine provide
the next step. For example, in a patient with a probable diagnosis more detailed information (eg, mutations of drug metabolizing
of rheumatoid arthritis, the diagnosis and the reasoning underly- enzymes—pharmacogenomics), the selection process will
ing it should be clear and should be shared with the patient. become more focused. In the example of the patient with
2. Consider the pathophysiologic implications of the probable rheumatoid arthritis, it would be important to
diagnosis: If the disorder is well understood, the prescriber is know whether the patient has a history of aspirin intoler-
in a much better position to offer effective therapy. ance or ulcer disease, whether the cost of medication is an

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