Determine the appropriate dosing regimen: The dosing regimen is determined primarily by the pharmacokinetics of the drug in that patient. If the patient is known to have disease of the organs required for elimination of the drug selected, adjustment of the average regimen is needed. For a drug such as ibuprofen, which is eliminated mainly by the kidneys, renal function should be assessed. If renal function is normal, the half-life of ibuprofen (about 2 hours) requires administration three or four times daily. The dose suggested in this book, drug handbooks, and the manufacturer’s literature is 400–800 mg four times daily.
6.
Devise a plan for monitoring the drug’s action and determine an end point for therapy: The prescriber should be able to describe to the patient the kinds of drug effects that will be monitored and in what way, including laboratory tests (if necessary) and signs and symptoms that the patient should report. For conditions that call for a limited course of therapy (eg, most infections), the duration of therapy should be made clear so that the patient does not stop taking the drug prematurely and understands why the prescription probably need not be renewed. For the patient with rheumatoid arthritis, the need for prolonged— perhaps indefinite—therapy should be explained, including how to obtain refills. The prescriber should also specify any changes in the patient’s condition that would call for changes in therapy. For example, in the patient with rheumatoid arthritis, development of gastrointestinal bleeding would require an immediate change in drug therapy and a prompt workup of the bleeding. Major toxicities that require immediate attention should be explained clearly to the patient.
7.
Plan a program of patient education: The prescriber and other members of the health team should be prepared to repeat, extend, and reinforce the information transmitted to the patient as often as necessary. The more toxic the drug prescribed, the greater the importance of this educational program. The importance of informing and involving the patient in each of the above steps must be recognized, as shown by experience with teratogenic drugs (see Chapter 59). Many pharmacies routinely provide this type of information with each prescription filled, but the prescriber must not assume that this will occur.
Although a prescription can be written on any piece of paper (as long as all of the legal elements are present), it usually takes a specific form. A typical printed prescription form for outpatients is shown in Figure 65–1.
In the traditional hospital setting, drugs have been prescribed on a particular page of the patient’s hospital chart called the physician’s order sheet (POS) or chart order. In the electronic medical
JOHN B. DOE, MD 1234 SOUTH NORTHEAST DR WEST CITY, CA 94999 (234) 555 6789 FOR: AD1234567 STATE LICENSE NO. ADDRESS: REFILL SIG: WARNING: OR UNTIL NO CHILDPROOF CONTAINER TIMES DATE: , MD (DRUG NAME AND STRENGTH) (QUANTITY) 10 11 98 1 2 3 4 6 7 5 12 13 14 15 16 17
FIGURE 65–1 Common form of outpatient prescription. Circled numbers are explained in the text.
records environment, prescriptions are executed via electronic order entry. The contents of that prescription are specified in the medical staff rules by the hospital’s Pharmacy and Therapeutics Committee or similar authority. The patient’s name is typed or written on the form; the orders consist of the name and strength of the medication, the dose, the route and frequency of administration, the date, other pertinent information, and the signature of the prescriber. If the duration of therapy or the number of doses is not specified (which is often the case), the medication is continued until the prescriber discontinues the order or until it is terminated as a matter of policy routine, eg, a stop-order policy.
A typical chart order might be as follows: 10:30 A.M.