Jobin Kunjumon Vilapurathu

Asst. ProfessorGrace College of Pharmacy, Palakkad

Mechanisms of ADR Numerous pharmacological actions of same

drug Immunological and hypersensitive reactions to

a drug Drug Interactions

The American Society of Health System Pharmacists (ASHP) defines ADRs as any unexpected, unintended, undesired or excessive response to a drug that includes

Requires discontinuing the drug Requires changing drug therapy Requires modifying dose Necessitates or prolong stay in Hospital Complicates Diagnosis Negatively affects prognosis or result in

temporary or permanent harm, disability or death

Type A (Predictable/ Augmented) Predictable on the basis of known pharmacologic

action of the drug Exaggerated but normal pharmacological actions

and are dose related

Type B (Qualitative) Bizarre or unpredictable effects, unexpected from

known pharmacological actions of drug Not dose related Usually hyper sensitive or immune-based further

sub divided to Type I ( IgE mediated) Type II ( IgG or IgM mediated cytotoxic reaction) Type III ( IgG mediated immune complex reaction) Type IV ( Cell mediated immune reaction)

Type C Both dose related and time related Occurring due to the long term use of the drug

Type D Only time related They are the delayed drug effects, such as due

to carcinogenicity or teratogenicity

Factors predisposing to ADRS Drug Related Factors Patient Related Factors

Drug Related Factors Dose Dosage form and delivery system Interactions between drugs

Patient Related Factors Age - Geriatrics Age – Pediatrics Concurrent diseases Hepatic disease Renal disease Other diseases Genetic factors Gender Nutrition

On basis of severity, classified as Minor : no therapy, antidote or prolongation of

hospitalization required Moderate : require change in drug therapy,

specific treatment, prolongs hospital stay Severe : life threatening, intensive treatment Lethal : death of patient

Prevention of ADR Avoid all inappropriate use of drugs Use appropriate dose, route & frequency Consider previous history of DR Rule out possibilities of DI Carry appropriate laboratory monitoring