METHODS TO STUDY DRUG SAFETY PROBLEMS animal experiments clinical trials epidemiological methods –spontaneous reporting case reports case series –Post-Marketing Surveillance (PMS) –prescription event monitoring –cohort studies intensive hospital monitoring –case - control studies –record-linkage meta -analysis

Spontaneous reporting Principle The alert health professional connects an undesirable medical event with drug exposure (SUSPICION) Reports suspicion to information collecting centre

ADVERSE DRUG REACTION A reaction which is noxious and unintended, and which occurs at doses normally used in man for the prophylaxis, diagnosis or therapy of disease, or for the modification of physiological function WHO definition

ADVERSE EVENT/EXPERIENCE Any untoward medical occurrence that may present during treatment with a pharmaceutical product but which does not necessarily have a causal relationship with this treatment WHO definition

SPONTANEOUS REPORTING Advantages – large population –all medicines –hospital and out-patient care –long perspective –patient analyses possible –inexpensive

SPONTANEOUS REPORTING Disadvantages –underreporting

Reporting varies with: severity of reaction time from market introduction promotional claims promotion of reporting system publicity of specific association

SPONTANEOUS REPORTING Disadvantages –difficult to detect delayed reactions reactions with high background incidence –important details often missing –number of exposed unknown –bias – underreporting

When to report? Early phase Simple message : –Report as soon as you suspect that drug therapy has resulted in a negative, unintended effect. i.e all suspected reactions Speed is essential

What to report? Adverse reactions –Type A –Type B Lack of effect –counterfeiting –resistance –interaction Quality problem Dependence and abuse Poisoning (?) Medical error (?)

What to report? Allopathic medicines –Prescription –OTC Traditional medicines Biologicals incl vaccines

What to report? Alternative approach Serious reactions ( definitions available ) Unexpected reaction (not in product info) Unusually severe reactions New medicines