Side effects from the use of drugs are the major cause of drug-related injuries, adverse events, and deaths. The FDA (FDA, CDER, 2005, 2007) has summarized various types of safety and efficacy risks from medicines (Fig. 16-1). Side effects are observed in clinical trials or postmarketing surveillance and result in listing of adverse events in the drug's labeling.
Sources of risk from drug products.
: FDA, CDER Report to the Nation: 2005.)
Some side effects are avoidable, and others are unavoidable. Avoidable side effects may include known drug–drug or drug–food interactions, contraindications, improper compliance, etc. In many cases, drug therapy requires an individualized drug treatment plan and careful patient monitoring. Some known side effects occur with the best medical practice and even when the drug is used appropriately. Examples include nausea from antibiotics or bone marrow suppression from chemotherapy. Medication errors include wrong drug, wrong dose, or incorrect drug administration. Some side effects are unavoidable. These uncertainties include unexpected adverse events, side effects due to long-term therapy, and unstudied uses and populations. For example, a rare adverse event occurring in fewer than 1 in 10,000 persons would not be identified in normal premarket testing. Chapters 12, 19, and 20 discuss how pharmcogenetics, pharmacokinetics, pharmacodynamics, and clinical considerations may improve drug efficacy and safety in many instances. Drug product quality is another important consideration. Quality is recognized and defined in ICH (International Conference on Harmonisation, which provides for international standards of new drug product quality; see below) as the suitability of either a drug substance or drug product for its intended use. This term includes such attributes as the identity, strength, and purity. Drug product quality defects are an important source of risk that affects drug product performance and can affect patient safety and therapeutic efficacy. Product quality includes strength and purity of the drug substance, the manufacturing process of the drug product and the monitoring of the manufacturing operations.1 This chapter will focus on drug product quality and risks of product quality defects that affect drug product performance. To minimize product quality defects, regulatory agencies such as the FDA must consider risk-based regulatory decisions supporting the drug approval process. These decisions depend on the scientific understanding of how formulation and manufacturing process factors affect product quality and performance and are the underlying basis for the development, manufacture, and quality assurance of the drug product throughout its lifecycle.2
1Pharmaceutical manufacturers are required to follow current Good Manufacturing Practices (cGMP) to ensure that the drug products are made consistently with high quality.
2A glossary of terms appears at the end of the chapter.
Drug product quality relates to the biopharmaceutic and physicochemical properties of the drug substance and the drug product to the in vivo performance of the drug. The ...