(1994; 115 pages) [French] [Spanish]
Chapter 2. Introduction to P-drugs
As a doctor you may see 40 patients per day or more, many of whom need treatment with a drug. How do you manage to choose the right drug for each patient in a relatively short time? By using P-drugs! P-drugs are the drugs you have chosen to prescribe regularly, and with which you have become familiar. They are your priority choice for given indications.
The P-drug concept is more than just the name of a pharmacological substance, it also includes the dosage form, dosage schedule and duration of treatment. P-drugs will differ from country to country, and between doctors, because of varying availability and cost of drugs, different national formularies and essential drugs lists, medical culture, and individual interpretation of information. However, the principle is universally valid. P-drugs enable you to avoid repeated searches for a good drug in daily practice. And, as you use your P-drugs regularly, you will get to know their effects and side effects thoroughly, with obvious benefits to the patient.
P-drugs, essential drugs and standard treatment guidelines
You may wonder what the relation is between your set of P-drugs and the WHO Model List of Essential Drugs or the national list of essential drugs, and existing standard treatment guidelines.
In general, the list of drugs registered for use in the country and the national list of essential drugs contain many more drugs than you are likely to use regularly. Most doctors use only 40-60 drugs routinely. It is therefore useful to make your own selection from these lists, and to make this selection in a rational way. In fact, in doing so you are preparing your own essential drugs list. Chapter 4 contains detailed information on the process of selection.
Institutional, national and international (including WHO) standard treatment guidelines have been developed to deal with the most common conditions, such as acute respiratory tract infections, diarrhoeal diseases and sexually transmitted diseases. They are based on good scientific evidence and consensus between experts. For these reasons they are a valuable tool for rational prescribing and you should consider them very carefully when choosing your P-drugs. In most cases you will want to incorporate them in your practice.
P-drugs and P-treatment
There is a difference between P-drugs and P-treatment. The key point is that not all diseases need to be treated with a drug. Not every P-treatment includes a P-drug! The concept of choosing a P-treatment was already introduced in the previous chapter. The process of choosing a P-drug is very similar and will be discussed in the following chapters.
How not to compile your list of P-drugs
Instead of compiling your own list, one of the most popular ways to make a list of P-drugs is just to copy it from clinical teachers, or from existing national or local treatment guidelines or formularies. There are four good reasons not to do this.
• You have final responsibility for your patient's well-being and you cannot pass this on to others. While you can and should draw on expert opinion and consensus guidelines, you should always think for yourself. For example, if a recommended drug is contraindicated for a particular patient, you have to prescribe another drug. If the standard dosage is inappropriate, you must adapt it. If you do not agree with a particular drug choice or treatment guideline in general, prepare your case and defend your choice with the committee that prepared it. Most guidelines and formularies are updated regularly.
• Through developing your own set of P-drugs you will learn how to handle pharmacological concepts and data. This will enable you to discriminate between major and minor pharmacological features of a drug, making it much easier for you to determine its therapeutic value. It will also enable you to evaluate conflicting information from various sources.
• Through compiling your own set of P-drugs you will know the alternatives when your P-drug choice cannot be used, for example because of serious side effects or contraindications, or when your P-drug is not available. The same applies when a recommended standard treatment cannot be used. With the experience gained in choosing your P-drugs you will more easily be able to select an alternative drug.
• You will regularly receive information on new drugs, new side effects, new indications, etc. However, remember that the latest and the most expensive drug is not necessarily the best, the safest or the most cost-effective. If you cannot effectively evaluate such information you will not be able to update your list, and you will end up prescribing drugs that are dictated to you by your colleagues or by sales representatives.