Clinical Pharmacology · MU Sofia

12. Clinical Drug Trials - Phase 4: Design, target population, aims.

Covers Phase IV studies carried out after a drug is licensed, explaining how they assess real-world effectiveness and detect rare or delayed adverse reactions in a broad, unselected patient population. It moves through the target population, the aims, and the study methods, set out in a table comparing spontaneous reporting, post-authorisation safety studies, cohort, case-control and registry designs. It also gives examples of drugs withdrawn or warned against after marketing and notes the black triangle monitoring mark.

Inside: 5 sections · 1 table · 15 flashcards · 2 min

Topic 12 of 30 in the MU Sofia syllabus for Clinical Pharmacology (Medicine, Year 5). The free AceMed note covers it in 5 sections, about 166 words (2 min of reading), with 15 flashcards.

In this note

  1. Introduction
  2. Target population
  3. Aims
  4. Methods
  5. Importance

Introduction

Phase IV (therapeutic use) covers studies done after the drug is licensed and marketed. It shows how the drug performs in everyday practice and finds problems that pre-marketing trials could not.

Target population

  • Unlimited: thousands to millions of real-world patients, including the elderly, children, pregnant women, patients with co-morbidities and many other drugs.
  • Always multi-centre; may be randomised trials or observational studies.

Aims

  1. Effectiveness: does the drug work in real-life conditions (as opposed to efficacy under ideal trial conditions)?
  2. Detect rare and delayed adverse reactions and interactions (pharmacovigilance).
  3. Compare with other treatments, study other doses, durations and populations.
  4. New indications (which then need regulatory approval), cost-effectiveness.

Importance

Many serious problems appeared only after marketing, leading to warnings or withdrawal: rofecoxib (myocardial infarction), cerivastatin (rhabdomyolysis), troglitazone (liver failure), thalidomide (phocomelia, before modern rules). New drugs in the EU carry the black triangle ▼ (additional monitoring) for at least 5 years.

Phase III shows efficacy in selected patients; phase IV shows effectiveness and rare harms in everyone who actually takes the drug.

Continue reading free

The whole note, all 5 sections, is free with an AceMed account, with its 15 flashcards. Premium adds flashcard recall, highlights and Ask AI.

Start freeAlready a member? Open the note