**Type I**

drug, wrong timing of dosages, premature termination of therapy or using additional medications. In order to improve patient compliance, the patient should be made to under‐ stand the nature and prognosis of the illness and what to expect from the medication by detailing both the acceptable and undesirable unwanted effects as well as signs of efficacy that

Patients frequently discontinue taking a medication such as septrin because they have not been told the necessity of continuing with the drug after the acute symptoms have subsided.

The effectiveness of physician-patient communication is inversely related to the error rate in the taking of drugs. A physician might prescribe a drug to be taken three times a day with meals for a patient who either eats only twice a day or sleeps all day and works at night. Therefore, an exploration of the patients eating, sleeping and working habits is necessary

The educational level of a patient may also require that the prescription is carefully worded and oral instructions given in the primary language of the patient since when such patients take three or more medications they are less likely to use them properly. It is therefore important to provide identifying symbols for each medication e.g. "Heart pill" or "sugar

Pharmacological formulations are potentially harmful to the individuals taking the drugs. There is need to ascertain the safety of new drugs before allowing them to be marketed. The following figures highlight the magnitude of the problem: ~ 10 – 20% of hospital‐ ized patients suffer adverse drug reactions, while 0.3 – 5.0% inpatients admissions and ~ 0.3% deaths in hospital are due to adverse drug reactions. Adverse drug reactions can be classified into two main categories: They may be dose related or non dose related with

Adverse drug reactions can occur because of the changes in the systemic availability of a formulation. For instance, the change of excipients in phenytoin capsules from CaSO4 to lactose leads to high availability and hence adverse drug reactions. Sometimes, adverse drug reactions can occur due to the presence of contaminants like bacteria if quality con‐ trol breaks down. Out-of-date formulations may also cause adverse drug reactions be‐ cause of degradation products arising from the drug e.g. outdated tetracycline may cause Faconis Syndrome (a type of rickets) because of the transformation product,epiandrote‐ tracycline. Dose related adverse reactions may also arise from pharmacokinetic variations in the individuals taking the drug. Pharmacokinetic variations may also arise due to hep‐ atic disease like advanced cirrhosis which lowers the clearance of drugs such as pheny‐ toin and morphine. The pharmacological variations could be environmental such as diet

pill"and to reduce the doses into once or twice daily regimens.

may help enforce compliances.

510 Drug Discovery

before a prescription is given.

**14.16. Adverse drug reactions**

each being short-term or long-term.

**14.17. Dose related adverse reactions**

or smoking, while others are genetic.

This anaphylaxis or immediate hypersensitivity reactions; the body reacts within five to thirty minutes. The IgE molecules fixed to mast cells and basophil leucocytes release histamine and other pharmacological mediators such as kinins. Drugs likely to cause are anaphylactic shock include;-penicillins, streptomycin, local anaesthetics etc.
