This chapter presents a first overview of the process of choosing a drug treatment. The process is illustrated using an example of a patient with a dry cough. The chapter focuses on the principles of a stepwise approach to choosing a drug, and is not intended as a guideline for the treatment of dry cough. In fact, some prescribers would dispute the need for any drug at all. Each of the steps in the process is discussed in detail in subsequent chapters.
A good scientific experiment follows a rather rigid methodology with a definition of the problem, a hypothesis, an experiment, an outcome and a process of verification. This process, and especially the verification step, ensures that the outcome is reliable. The same principles apply when you treat a patient. First you need to define carefully the patient's problem (the diagnosis). After that, you have to specify the therapeutic objective, and to choose a treatment of proven efficacy and safety, from different alternatives. You then start the treatment, for example by writing an accurate prescription and providing the patient with clear information and instructions. After some time you monitor the results of the treatment; only then will you know if it has been successful. If the problem has been solved, the treatment can be stopped. If not, you will need to re-examine all the steps.
Example: patient 1
You sit in with a general practitioner and observe the following case. A 52-year old taxi-driver complains of a sore throat and cough which started two weeks earlier with a cold. He has stopped sneezing but still has a cough, especially at night. The patient is a heavy smoker who has often been advised to stop. Further history and examination reveal nothing special, apart from a throat inflammation. The doctor again advises the patient to stop smoking, and writes a prescription for codeine tablets 15 mg, 1 tablet 3 times daily for 3 days.
Let’s take a closer look at this example. When you observe experienced physicians, the process of choosing a treatment and writing a prescription seems easy. They reflect for a short time and usually decide quickly what to do. But don't try to imitate such behaviour at this point in your training! Choosing a treatment is more difficult than it seems, and to gain experience you need to work very systematically.
In fact, there are two important stages in choosing a treatment. You start by considering your ‘first-choice’ treatment, which is the result of a selection process done earlier. The second stage is to verify that your first-choice treatment is suitable for this particular patient. So, in order to continue, we should define our first-choice treatment for dry cough.