have been defined by the European Parliament and the Council of the European
Union as, “any untoward medical occurrence in a patient or clinical trial
subject administered a medicinal product and which does not necessarily have a
causal relationship with this treatment.” These changes are compared to
baseline health status (i.e. hypertension) before the beginning of the trial.
Ireland and Europe:
Reporting Procedures (for drugs and vaccines);
Phases of Clinical Trials;
4 phases (1)
1: Initial administration of the drug under investigation. Safety is assessed.
Dosage ranges are determined by volunteers who may be healthy or specifically
chosen. The drug is characterised by how it is metabolised, absorbed and
excreted, as well as potential drug-drug interactions. Side effects are
2: Randomised trials where both a placebo and experimental drug are involved.
These trials can be ‘blinded’ to prevent biasness and for a full comparison to
be made on the safety of the new drug as well as its effectiveness. Criteria’s
are usually made for those who can be involved in the testing and are closely
monitored. From this, further objectives and targets can be set out for Phase
3. Dosages are also determined for phase 3 trials here.
3: Large scaled, randomised testing is done. Over these few years,
pharmaceutical companies can determine the effectiveness and efficiency of the
drug under investigation. A range of potential adverse reactions are
established. Therapeutic benefits are established. Companies can then go on to
look for the European Medicines Agency’s (EMA) approval.
Phase 4: Post
Marketing Surveillance Trials. Searching for drug optimisation that were not
previously considered before approval. These may include new formulas, doses or
(1) ICH Expert Working Group, General
Considerations for Clinical Trials E4 (1997), current step 4 version, page 6