easestudynotes

ADVERSE DRUG REACTION Any noxious change in the body which is suspected to be due to a drug at doses normally used in man. It may requires treatment or decrease in dose or caution in the future use of the same drug GRADING OF SEVERITY OF ADVERSE DRUG REACTIO NS : Minor : No therapy, antidote or prolongation of hospitalization is required. Moderate : Requires change in drug therapy, specific treatment or prolongs hospital stay. Severe : Potentially life-threatening, causes permanent damage or requires intensive medical treatment. Lethal : Directly or indirectly contributes to death of the patient. CLASSIFICATIONS OF ADR A (Augmented) B (Bizarre) C (Continuous) D (Delayed) E (Ending Use) F (Failure of Efficacy) Broadly Type- A (Predictable)- Based on pharmacological properties Type- B (Non-predictable) – Based on Immunological ...

IDIOSYNCRATIC REACTIONS DEFINITION: Idiosyncratic drug reactions are “Adverse drug reactions that do not occur in most patients at any dose and do not involve the known pharmacological properties of the drug and cause remain unknown” A genetic or acquired abnormality in a particular metabolic pathway. Certain idiosyncratic reactions can result from genetic polymorphisms that cause individual differences in drug pharmacokinetics Adverse reactions, such as cardiac arrhythmias caused by drugs that affect potassium channels, would not be idiosyncratic because they involve known pharmacological properties of the drug. Example Antipsychotic drugs such as chlorpromazine and clozapine cause infrequent reactions such as rhabdomyolysis (breakdown of striated muscle) and liver toxicity One tablet of Chloroquine may cause vomiting and abdominal pain .

Action of Drugs (Pharmacodynamics ) Pharmacodynamics is the study of drug effects and modification of the action of one drug by another drug at the therapeutic dose in the body Principles of Drug Action Drugs do not impart new functions to any system, organ or cell; they only alter the pace of ongoing activity. The basic types of drug action can be broadly classed as: 1. Stimulation - It refers to selective enhancement of the level of activity of specialized cells, e.g. adrenaline stim ulates heart, pilocarpine stimulates salivary glands. 2. Depression- It means selective diminution of activity of specialized cells, e.g. barbiturates depress CNS, quinidine depresses heart. Certain drugs stimulate one type of cells but depress the other, e.g. acetylcholine stimulates intestinal smooth muscle but depresses SA node in heart. Thus,. most drugs cannot be simply classed as stimulants or depressants. 3. Irritation - This means a nonselective, often noxious effect and is particul...