Once a patient with a clinical problem has been evaluated and a diagnosis has been reached, the practitioner can often select from a variety of therapeutic approaches. Medication, surgery, psychiatric treatment, radiation, physical therapy, health education, counseling, further consultation (second opinions), and no therapy are some of the options available. Of these options, drug therapy is by far the one most frequently chosen. In most cases, this requires the writing of a prescription. A written prescription is the prescriber’s order to prepare or dispense a specific treatment—usually medication—for a specific patient. When a patient comes for an office visit, the physician or other authorized health professional prescribes medications 67% of the time, and an average of one prescription is written per office visit because more than one prescription may be written at a single visit.
In this chapter, a plan for prescribing is presented. The physical form of the prescription, common prescribing errors, and legal requirements that govern various features of the prescribing process are then discussed. Finally, some of the social and economic factors involved in prescribing and drug use are described.
Like any other process in health care, writing a prescription should be based on a series of rational steps as follows: 1.
Make a specific diagnosis: Prescriptions based merely on a desire to satisfy the patient’s psychological need for some type of therapy are often unsatisfactory and may result in adverse effects. A specific diagnosis, even if it is tentative, is required to move to the next step. For example, in a patient with a probable diagnosis of rheumatoid arthritis, the diagnosis and the reasoning underlying it should be clear and should be shared with the patient.
2.
Consider the pathophysiologic implications of the diagnosis: If the disorder is well understood, the prescriber is in a much better position to offer effective therapy.
For example, increasing knowledge about the mediators of inflammation makes possible more effective use of nonsteroidal anti-inflammatory drugs (NSAIDs) and other agents used in rheumatoid arthritis. The patient should be provided with the appropriate level and amount of information about the pathophysiology. Many pharmacies, websites, and disease-oriented public and private agencies (eg, Arthritis Foundation, American Heart Association, American Cancer Society, etc) provide information sheets suitable for patients.
3.
Select a specific therapeutic objective: A therapeutic objective should be chosen for each of the pathophysiologic processes defined in the preceding step. In a patient with rheumatoid arthritis, relief of pain by reduction of the inflammatory process is one of the major therapeutic goals that identifies the drug groups that should be considered. Arresting the course of the disease process in rheumatoid arthritis is a different therapeutic goal, which might lead to consideration of additional drug groups and prescriptions.
4.
Select a drug of choice: One or more drug groups will be suggested by each of the therapeutic goals specified in the preceding step. Selection of a drug of choice from among these groups follows from a consideration of the specific characteristics of the patient and the clinical presentation, a selection process that has been emphasized as part of “precision medicine.” For certain drugs, characteristics such as age, other diseases, and other drugs being taken (because of the risk of duplicative therapy or drug-drug interactions) are extremely important in determining the most suitable drug for management of the present complaint. As the tools of precision medicine provide more detailed information (eg, mutations of drug metabolizing enzymes—pharmacogenomics), the selection process will become more focused. In the example of the patient with probable rheumatoid arthritis, it would be important to know whether the patient has a history of aspirin intolerance or ulcer disease, whether the cost of medication is an especially important factor and the nature of the patient’s insurance coverage, and whether there is a need for once-daily dosing. Based on this information, a drug would probably be selected from the NSAID group. If the patient does not have ulcer disease but does have a need for low-cost treatment, ibuprofen or naproxen would be a rational choice.
5.