When selecting a P-drug, it is important to remember that you are choosing a drug of first choice for a common condition. You are not choosing a drug for an individual patient (when actually treating a patient you will verify whether your P-drug is suitable for that particular case - see Chapter 8).
To be able to select the best drug for a given condition, you should study the pathophysiology of the disease. The more you know about this, the easier it is to choose a P-drug. Sometimes the physiology of the disease is unknown, while treatment is possible and necessary. Treating symptoms without really treating the underlying disease is called symptomatic treatment.
When treating an individual patient you should start by carefully defining the patient’s problem (see Chapter 6). When selecting a P-drug you only have to choose a common problem to start the process.