PharmD cases:Is the standard duration of treatment suitable for this patient?
Many doctors not only prescribe too much of a drug for too long, but also frequently too little of a drug for too long, but also frequently too little of a drug for too short a period. In one study about 10% of  patients on benzodiazepines received them for a year or longer. Another study  showed that 16% of outpatients with cancer still suffered from pain because doctors we afraid to prescribe morphine for a long period. They mistook tolerance for addiction. The duration of the treatment and the quality of drugs prescribed should also be effective and safe for the individual patient.

Overprescribing leads to many undesired effects. The patient receives unnecessary treatment, or drugs may lose some of their potency. Unnecessary side effects may occur. The quantity available may enable the patient to overdose. Drug dependence and addiction may occur. Some reconstituted drugs, such as eye drops and antibiotics syrups, may become contaminated. It may be very inconvenient for the patient to take so many drugs. Last, but not least, valuable and often scarce resources are wasted.

Underprescribing is also serious. The treatment is not effective, and more aggressive or expensive treatment may be needed later. Prophylaxis may be inconvenient to return for further treatment. Money spent on ineffective treatment is money wasted.

Exercise: patients 21-28
For each of the following cases verify whether the duration of treatment and total quantity of the drugs are suitable (effective, safe). In all cases you may assume that the drugs are your P-drugs.

Patient 21:
Woman, 56 years. Newly diagnosed depression. R/amitriptyline 25 mg, one tablet daily at night, give 30 tablets.

Patient 22:
Child, 6 years. Giardiasis with persistent diarrhoea. R/metronidazole 200 mg/5 ml oral suspension, 5 ml three times daily, give 105 ml.

Patient 23:
Man, 18 years. Dry cough after a cold. R/codeine 30 mg, 1 tablet three times daily, give 60 tablets.

Patient 24:
Woman, 62 years. Angina pecoris, waiting for referral to a specialist. R/glyceryl trinitrate 5 mg, as necessary 1 tablet sublingual, give 60 tablets.

Patient 25:
Man, 44 years. Sleeplessness. Comes for a refill, R/diazepa, 5 mg, 1 tablet before sleeping, give 60 tablets.

Patient 26:
Girl, 15 years. Needs malaria prophylaxis for a two week trip to Ghana. R/mefloquine 250 mg, 1 tablet weekly, give 7 tablets; start one week before departure and continue four weeks after return.

Patient 27:
Boy, 14 years. Acute conjunctivities. R/tetracycline 0.5 % eye drops, first 3 days every hour 1 drop, then 2 drops every six hours, give 10 ml.

Patient 28:
Woman, 24 years. Feels weak and looks a bit anaemic. No Hb result available. R/ferrous sulfate 60 mg tablets, 1 tablet three times daily, give 30 tablets.

Patient 21 (depression)
A dose of 25 mg per day is probably insufficient to treat her depression. Although she can start with such a low dose for a few days or a week, mainly to get used to side effects of the drug, she may finally need 100-150 mg per day. With 30 tablets the quantity is sufficient for one month, if the dosage is not changed before that time. But is it safe? At the beginning  of the treatment the effect and side effects cannot be foreseen. And if the treatment has to be stopped, the remaining drugs are wasted. The risk of suicide also has to be considered: depressive patients are more liable to commit suicide in the initial stages of treatment when they become more active because of the drug, but still feel depressed. For these reasons 30 tablets are not suitable. It would be better to start with 10 tablets, for the first week or so. If she reacts well you should increase the dose.

Patient 22 (giardiasis)
With most infections time is needed to kill the microbes, and short treatments may not be effective. However, after prolonged treatment the micro-organisms  may develop resistance and more side effects will occur. In this patient the treatment is both effective and safe. Giardiasis with persistent diarrhoea needs to be treated for one week, and 105 ml is exactly enough for that period. Maybe it is even too exact. Most pharmacists do not want to dispense quantities such as 105 ml or 49 tablets. They prefer rounded figures, such as 100 ml or 50 tablets, because calculating is easier and drugs are usually stocked or packed in such quantities.

Patient 23 (dry cough)
The quantity of tablets is much too high for this patient. The persistent dry cough prevents healing of the irritated bronchial tissue. Since tissue can regenerate within three days the cough needs to be suppressed for five days at most, so 10-15 tablets will be sufficient. Although a larger quantity will not harm the patient, it is unnecessary, inconvenient and needlessly expensive. Many prescribers would argue that no drug is needed at all.

Patient 24 (angina)
For this patient the quantity is excessive. She will not use 60 tablets before her appointment with the  specialist. And did you remember that the drug is volatile? After some time the remaining tablets will no longer be effective.

Patient 25 (sleeplessness)
The diazepam refill for patient 25 is worrying. You suddenly remember that he came for a similar refill recently and check the medical record. It was two weeks ago! Looking more closely you find that he has used diazepam four times daily for the last three years. This treatment has been expensive, probably ineffective and has resulted in a severe dependency. You should talk to the patient at the next visit and discuss with him how he can gradually come off the drug.

Box 6:        Repeat prescriptions in practice

In long-term treatment, patient adherence to treatment can be a problem. Often the patient stops taking the drug when the symptoms have disappeared or if side effects occur. For patients with chronic conditions repeat prescriptions are often prepared by the receptionist or assistant and just signed by the physician. This may be convenient for doctor and patient but is has certain risks, as the process of renewal becomes a routine, rather than a conscious act. Automatic refills are one of the main reasons for overprescribing in industralized countries, especially in chronic conditions. When patients live far away, convenience may lead to prescriptions for longer  periods. This may also result in over prescribing. You should see your patients on long-term treatment at least four times per year.

Patient 26 (malaria prophylaxis)
There is nothing wrong with this prescription which follows the WHO guidelines on malaria prophylaxis for traveller to Ghana. The dosage schedule is correct, and she received enough tablets for the trip plus four weeks afterwards. Apart from a small risk of drug resistance this drug treatment is effective and safe.

Patient 27  (acute conjunctivitis)
The prescription of 10 ml eyedrops seems adequate, at first sight. In fact, eyedrops are usually prescribed in bottles of 10 ml. But did you ever check how many drops there are in a bottle of 10 ml? One ml is about 20 drops, so 10 ml is about 200 drops. One drop every hour for the first three days means 3x24 = 72 drops. That leaves about 128 drops in the bottle. Two drops four times per day for the remaining period is 8 drops a day. That is for another 130/8 = 16 days. The total treatment therefore covers 3 - 16 = 19 days! Yet, seven days treatment at most should be enough for bacterial conjuctivitis. After some arithmetic (72 + (4 x 8) = 104 drops = 104 x 0.05 = 5.2 ml) you conclude that 5 ml will be enough in future. This will also prevent any leftovers from being used again without a proper diagnosis. Even more important, eyedrops become contaminated after a few weeks, especially if they are not kept cool, and can cause severe eye infections.

Patient 28 (weakness)
Did you notice that this is a typical example of a prescription without a clear theapeutic objective? If the diagnosis is uncertain, the Hb should be measure. If the patient is really anaemic she will need much more iron than the ten days given here. She will probably need treatment for several weeks or months, with regular Hb measurements in between.


Verifying whether your P-drug is also suitable for the individual patient in front of you is probably the most important step in the process of rational prescribing. It also applies if you are working in an environment in which essential drugs lists, formularies and treatment guidelines exist. In daily practice, adapting the dosage schedule to the individual patient is probably the most common change that you will make.


Step 3: Verify that your P-drug is suitable for this patient

3A       Are the active substance and dosage form suitable?
            Effective:        Indication (drug really needed)?
                                    Convenience (easy to handle, cost)?
            Safe:                Contraindications (high risk groups, other diseases)?

3B       Is the dosage schedule suitable?
            Effective:        Adequate dosage (curve within window)?
                                    Convenience (easy to memorize, easy to do)?
            Safe:                Contraindications (high risk groups, other diseases)?
                                    Interactions (drugs, food, alcohol)?

3C       Is the duration suitable?
            Effective:        Adequate duration (infections, prophylaxis, lead time)?
                                    Convenience (easy to store, cost)?
            Safe:                Contraindications (side effects, dependence, suicide)?
                                    Quantity too large (loss of quality, use of leftovers)?

If necessary, change the dosage form, the dosage schedule or the duration of treatment.

In some cases it is better to change to another P-drug.

Exercise: Patient 29-32
Write a prescription for each of the following patients. Prescriptions are discussed below.

Patient 29:
Boy, 5 years. Pneumonia with greenish sputum. Your P-drug is amoxicillin syrup.

Patient 30:
Woman, 70 years. Moderate congestive cardiac failure. For several years on digoxin 0.25 mg 1 tablet daily. She phones to ask for a repeat prescription. As you have not seen her for some time you ask her to call. During the visit she complains of slight nausea and loss of appetite. No vomiting or diarrhoea. You suspect side effects of digoxin, and call her cardiologist. As she has an appointment with him next week, and he is very busy, he advises you to halve the dose until then.

Patient 31:
Woman, 22 years. New patient. Migraine with increasingly frequent vomiting. Paracetamol no longer effective during attacks. You explain to her that the paracetamol does not work because she vomits the drug before it is absorbed. You prescribe paracetamol plus an anti-emetic suppository, metoclopramide, which she should take first, and wait 20-30 minutes before taking the paracetamol.

Patient 32:
Man, 53 years. Terminal stage of pancreatic cancer, confined to bed at home. You visit him once a week. Today his wife calls and asks you to come earlier because he is in considerable pain. You go immediately. He has slept badly over the weekend and regular painkillers are not working. Together you decide to try morphine for a week. Making sure not to underdose him, you start with 10 mg every six hours, with 20 mg at night. He also has non-insulin dependent diabetes, so you add a refill for his tolbutamide.

There is nothing wrong with any of the four prescriptions (Figures 6,7,8 and 9). However, a few remarks can be made. Repeat prescriptions, such as the one for patient 30, are permitted. Many prescriptions are like that. But they also need your full attention. Do not write a repeat prescription automatically! Check how many times it has been repeated. Is it  still effective? It is still safe? Does it still meet the original needs?

For the opiate for patient 32, the strength and the total  amount have been written in words so they  cannot easily be altered. The instructions are detailed and the maximum daily dose is mentioned. In some countries it is mandatory to write an opiate prescription on a separate prescription sheet.


A prescription should include:

*      Name, adress, telephone of prescriber
*      Date
*      Generic name of the drug, strength
*      Dosage form, total amount
*      Label: instructions, warning
*      Name, address, age of patient
*      Signature or initials of prescriber

Exercise: Patients 34-38
Review the following prescriptions and list the most important instructions and warning that should be given to the patient. You may consult your pharmacology  books. Cases are discussed below.

Patient 34:
Man, 56 years. Newly diagnosed depression. R/amitriptyline 25 mg, 1 tablet daily at night for one week.

Patient 35:
Woman, 28 years. Vaginal trichomonas infection. R/metronidazole 500 mg, 1 vaginal tablet daily for 10 days.

Patient 36:
Man, 45 years. Newly diagnosed essential hypertension. R/atenolol 50 mg, 1 tablet daily.

Patient 37:
Boy, 5 years. Pneumonia. R/amoxicillin syrup, 5 ml (=250 mg) three times daily.

Patient 38:
Woman, 22 years. Migraine. R/paracetamol 500 mg, 2 tablets 20 min. after R/metoclopramide 10 mg 1 suppository, at the onset of an attack.

Patient 34 (depression)
It will take approximately two to three weeks before the patients starts to feel better, but side effects, such as dry mouth, blurred vision, difficulty in urinating and sedation, may occur quickly. Because of this many patients think that the treatment is worse than the disease and stop taking the drug. If they are not told that this may happen and that these effects disappear after some time, adherence to treatment will be poor. For this reason a slowly rising dosage schedule is usually chosen, with the tablets taken before bedtime. This should be explained carefully to the patient. Older people, especially, may not remember difficult dosage schedules. Write them down, or give a medication box. You can also ask the pharmacist to explain it again (write this on the prescription). Instructions are to follow the dosage schedule, to take the drug at bedtime and not to stop the treatment. Warnings are that the drug may slow reactions, especially in combination with alcohol.

Patient 35 (vaginal trichomonas)
As in any infection the patient should be told why the course has to be finished completely, even when the symptoms disappear after two days. The patient should also be informed that treatment is useless if the partner is not treated as well. Careful and clear instructions are needed for vaginal tablets. If possible, pictures or leaflets should be used to show the procedure. Side effects of metronidazole are a metal taste, diarrhoea or vomiting, especially with alcohol, and dark urine. Give a clear warning against the use of alcohol.

Patient 36 (essential hypertension)
The problem with the treatment of hypertension is that patients rarely experience any positive effect of the drugs, yet they have to take them for a long time. Adherence to treatment may be very poor if they are not told why they should take the drug, and if treatment is not monitored regularly. The patient should be told that the drug prevents complications of high blood pressure (angina, heart attack, cerebral problems). You can also say that you will try to decrease the dosage after three months, or even stop the drug entirely. Remember to check whether the patient has a history of asthma.

Patient 37 (boy with pneumonia)
The pacient´s mother should be told that the penicillin will need some time to kill the bacteria. If the course of treatment is stopped too soon, the stronger ones will survive, and cause a second, possibly more serious infection. In this way she will understand why it is necessary to finish the course. Knowing that any side effects will disappear soon will increase the likelihood of adherence to treatment. She should also be told to contanct you immediately if a rash, itching or rising fever occur.

Patient 38 (migraine)
In addition to other information the important instruction here is that the drug (preferably a suppository) should be taken 20 minutes before the analgesic, to prevent vomiting. Because of possible sedation and loss of coordination she should be warned not to drive a car or handle dangerous machinery.

Sample page of a personal formulary

Tablet 20,100 mg                    Beta blocker                                        ATENOLOL

*      DOSAGE
Hypertension: start with 50 mg in the morning. Average: 50-100 mg per day.
Angina pectoris: 100 mg per day in 1-2 doses
Adjust to each patient individually, start as low as possible. Raise the dose after 2 weeks, if needed.
Hypertension: drug decreases blood pressure, patient will usually not notice any effect. Drug will prevent complications of high blood pressure (angina, heart attack, cerebrovascular accident).
Angina pectoris: decreases blood pressure, prevents the heart from working too hard, preventing chest pain.
Side effects: hardly any, sometimes slight sedation.
Take the drug .. times per day, for ... days
Angina pectoris: do not suddently stop taking the drug
Next appointment
Hypertension: one week.
Angina pectoris: within one month, earlier if attacks occur more frequently, or become more severe
*      FOLLOW-UP
Hypertension: during first few months pulse and blood pressure should be checked weekly. Try to decrease dosage after three months. Higher dosages do not increase therapeutic effect, but may increase side effects. Try to stop treatment from time to time.
Angina pectoris: in case frequency or severity of the attacks increase, more diagnostic tests or other treatment are needed. Try to stop drug treatment from time to time.
Exercise: patient 39-42
In the following cases, try to decide whether the treatment can be stopped or not. Cases are discussed below.

Patient 39:
Man, 40 years. Review visit after pneumonia, treated with oral ampicillin (2 grams daily) for one week. No symptoms remain, only slight unproductive cough. Examination normal.

Patient 40:
Man, 55 years. Severe myalgia and undefined arthritis  for many years. Has been on prednisolone (50 mg daily) and indometacin (10 mg daily) for a long time. Epigastric pain and pyrosis over several months, for which he takes aluminum hydroxide tablets from time to time. During the consultation he complains that the epigastric pain and pyrosis have not disappeared; in fact they have become worse.

Patient 41:
Woman, 52 years. Mild hypertension for the past two years. Responded well to a thiazide diuretic (25 mg daily). The maintenance dose has already been decreased twice because her blood pressure had dropped to around normal. She regularly forgets to take the drug.

Patient 42:
Man, 75 years. Had been prescribed temazepam for one week, (10 mg daily) because of sleeplessness after his wife died six months ago. He asks for more, because he is afraind he will still not be able to sleep.

Patient 39 (pneumonia)
The course of treatment was defined in advance. It was effective and without side effects. The ampicillin can be stopped.

Patient 40 (epigastric pain)
In this case the treatment has not been effective because the epigastric pain is a side effect of the drugs used for myalgia. The treatment that really needs monitoring is the anti-inflammatory drugs, not the aluminium hydroxide. The problem can be solved by finding out whether the pain occurs at certain times, rather than being continuous. In this case the dosage schedule could be adjusted to reach peak plasma concentrations at those times, and the total daily dose could be lowered. The lesson to be learned from this patient is that it is better to reconsider the original therapy rather than to „treat“ its side effects with another drug.

Patient 41 (mild hypertension)
This treatment seems effective and without side effective and without side effects. The patient is no longer hypertensive and may not need continued therapy, especially since she regularly forgets to take the drug. You can stop the treatment for assessment but you must continue to monitor the patient.

Patient 42 (insomnia)
As the patient wants to continue the treatment it was obviously effective. However, benzodiazepines can produce psychological and physical dependence when taken regularly for more than a few weeks. In addition, tolerance develops quickly and this can lead patient and also tell him that the nature of the sleep induced by such drugs is not the same as normal sleep, but the result of suppressed brain activity. Encourage him to try to return to natural sleep patterns; possibly a warm bath or a hot milk drink will help to promote relaxation before bedtime. It may also help to encourage him to express his feeling about his loss; acting as a sympathetic listener is probably your major therapeutic role in this case, rather than prescribing more drugs. In this case the drug can be stopped at once because it was only used for one week. This cannot be done when patients have taken benzodiazepines for longer periods of time.


Step 6: Monitor (and stop?) the treatment

Was the treatment effective?

a.   Yes, and disease cured:                  Stop the treatment

b.   Yes, but not yet completed:           Any serious side effects?
n No: treatment can be continued
n Yes: reconsider dosage or drug choice

c.   No, disease not curred:                  Verify all steps:
n Diagnosis correct?
n Therapeutic objective correct?
n P-drug suitable for this patient?
n Drug prescribed correctly?
n Patient instructed correctly?
n Effect monitored correctly?