Emotional factors

eg. Placebo response.
Placebo: It is a Latin word meaning” I shall please” and it is a tablet looking exactly like the active treatment but containing no active component. It refers originally to substances merely to please the patient when no specific treatment was available.
Adverse drug reactions:
The drugs that produce useful therapeutic effect may also produce unwanted or toxic effects. It has been estimated that about 0.5% of patients who die in hospitals do so as a result of their treatment rather than the condition for which they were treated. Serious systemic drug toxicity may result from overdoses. If is always an exaggeration of its pharmacological actions and some times it is predictable. e.g. Hypotension following antihypertensive drugs. Hypoglycaemia following insulin.
An adverse drug reaction is defined as any response to a drug that is noxious and unintended and that occurs at doses used in man for prophylaxis, diagnosis or therapy (WHO).
The adverse effects are 1)Side effects 2)untoward effects 3)allergic reactions 4)idiosyncratic reactions and 5)teratogenic effects.

1) Side effects: Side effects are infact pharmacological effects produced with therapeutic dose of the drug. e.g: Dryness of mouth with atropine which is troublesome in peptic ulcer patients and useful when used as a preanaesthetic medication.
2) Untoward effects: Untoward effects develop with therapeutic dose of a drug. They are undesirable and if very severe, may necessitate the cessation of treatment. e.g: Diarrhoea with ampicillin and potassium loss with diuretics.
3) Allergic reactions: Most of the drugs and sera used in therapeutics are capable of causing allergic or hypersensitive reactions. These reactions may be mild or very severe like anaphylaxis. When an individual has been sensitized to an antigen (allergen) further contact with that antigen can some times lead to tissue damaging reactions. These allergic reactions are 4 types.
• Type-I reactions or anaphylactic reactions (Immediate hypersensitive reaction).
• Type-II reactions or cytotoxic reactions.
• Type-III reactions or immune complex mediated reactions.
• Type-IV reactions or cell mediated reactions (Delayed hypersensitive reactions).
4) Idiosyncratic reactions: The term idiosyncrasy means one’s peculiar response to drugs.
With the increasing knowledge of pharmacogenetics, many idiosyncratic reactions have been found to be genetically determined.
e.g: Drugs like primaquine, sulfonamides and dapsone may cause haemolysis in patients with glucose -6 phosphate dehydrogenase defeciency.
5) Teratogenic effect: Some drugs given in the first three months of pregnancy may cause congenital abnormalities and are said to be teratogenic. The best known example is thalidomide which results in early easily recognizable bnormalities such as absent or grossly abnormal limbs.
Other drugs with teratogenic potential are androgens, steroids, anti convulsants, anti neoplastic drugs, cortisone, lithium, pencillamine, tricyclic antidepressants and warfarin.