(1994; 115 pages) [French] [Spanish]
The process of rational prescribing
Now that we have defined our P-treatment for dry cough, we can review the process of rational prescribing as a whole. This process consists of six steps, each of which is discussed briefly, using the example of our patient with a dry cough. Each step is explained in detail in Part 3.
Step 1: Define the patient's problem
The patient's problem can be described as a persistent dry cough and a sore throat. These are the symptoms that matter to the patient; but from the doctor's viewpoint there might be other dangers and concerns. The patient's problem could be translated into a working diagnosis of persistent dry cough for two weeks after a cold. There are at least three possible causes. The most likely is that the mucous membrane of the bronchial tubes is affected by the cold and therefore easily irritated. A secondary bacterial infection is possible but unlikely (no fever, no green or yellowish sputum). It is even less probable that the cough is caused by a lung tumour, although that should be considered if the cough persists.
Step 2: Specify the therapeutic objective
Continuous irritation of the mucous membranes is the most likely cause of the cough. The first therapeutic objective is therefore to stop this irritation by suppressing the cough, to enable the membranes to recover.
Step 3: Verify whether your P-treatment is suitable for this patient
You have already determined your P(ersonal) treatment, the most effective, safe, suitable and cheap treatment for dry cough in general. But now you have to verify whether your P-treatment is also suitable for this particular patient: is the treatment also effective and safe in this case?
In this example there may be reasons why this advice is unlikely to be followed. The patient will probably not stop smoking. Even more important, he is a taxi-driver and cannot avoid traffic fumes in the course of his work. So although advice should still be given, your P-drug should also be considered, and checked for suitability. Is it effective, and is it safe?
Codeine is effective, and it is not inconvenient to take a few tablets every day. However, there is a problem with safety because the patient is a taxi-driver and codeine has a sedative effect. For this reason it would be preferable to look for a cough depressant which is not sedative.
Our two alternatives within the group of opiates (noscapine, pholcodine) share the same side effect; this is often the case. The antihistamines are even more sedative and probably not effective. We must therefore conclude that it is probably better not to prescribe any drug at all. If we still consider that a drug is needed, codeine remains the best choice but in as low a dosage as possible, and for a few days only.
Step 4: Start the treatment
The advice should be given first, with an explanation of why it is important. Be brief and use words the patient can understand. Then codeine can be prescribed: R/codeine 15 mg; 10 tablets; 1 tablet 3 times daily; date; signature; name, address and age of the patient, and the insurance number (if applicable). Write clearly!
Step 5: Give information, instructions and warnings
The patient should be informed that codeine will suppress the cough, that it works within 2-3 hours, that it may cause constipation, and that it will make him sleepy if he takes too much of it or drinks any alcohol. He should be advised to come back if the cough does not go within one week, or if unacceptable side effects occur. Finally he should be advised to follow the dosage schedule and warned not to take alcohol. It's a good idea to ask him to summarize in his own words the key information, to be sure that it is clearly understood.
Step 6: Monitor (stop) the treatment
If the patient does not return, he is probably better. If there is no improvement and he does come back there are three possible reasons: (1) the treatment was not effective; (2) the treatment was not safe, e.g. because of unacceptable side effects; or (3) the treatment was not convenient, e.g. the dosage schedule was hard to follow or the taste of the tablets was unpleasant. Combinations are also possible.
If the patient's symptoms continue, you will need to consider whether the diagnosis, treatment, adherence to treatment and the monitoring procedure were all correct. In fact the whole process starts again. Sometimes there may be no end solution to the problem. For example, in chronic diseases such as hypertension, careful monitoring and improving patient adherence to the treatment may be all that you can do. In some cases you will change a treatment because the therapeutic focus switches from curative to palliative care, as in terminal cancer or AIDS.