5 - Adverse drug reactions and drug interactions

Summary

This chapter aims to help you consider the problems associated with the prescribing of medicines and their management. You owe it to your patient to ensure that these issues are taken seriously. Failure to manage them can result in patient harm, loss of patient trust in your abilities, and abandonment, by the patient, of worthwhile medication.

Books on adverse drug reactions often include lists of medicines that are associated with different adverse reactions. These lists are difficult to remember and often oversimplify the facts. The first part of this chapter provides a background to adverse drug reactions. The second part looks at drug interactions where the combination of therapies can cause problems. The third part describes some information sources that can be used to manage adverse drug reactions and drug interactions. Overall the aim is to give a general background and explain how to optimize patient care.

Part 1 Adverse drug reactions

Adverse drug reactions (ADRs) are a major drain on NHS resources. In 2002, Bandolier Extra (Wiffen, 2002) stated that 7% of patients admitted to hospital are affected with ADRs. The cost to the NHS in England was estimated to be £380 million per year.

It is often difficult to decide if a patient's symptom is an ADR or a symptom of a new disease. This can lead to patients being exposed to unnecessary investigations and worry while the offending medicine is continued, and the patient continues to be exposed to its adverse effects.