Administration of medicines: Introduction

Last updated: Tuesday, July 12, 2022

☞ Why this subject matters...

Pharmacists are expected to know about how medicines are given in practice, and the limitations and problems caused by different routes of administration. It's a very practical, but fundamental, side of the pharmacist's role: how to get medicines into every patient in a safe and convenient way.

This tutorial covers concepts that you may not have come across if you haven't worked in a hospital before. It describes common clinical problems and gives you troubleshooting tips for resolving administration issues, but it does not give an in-depth description of each method of giving medicines.

Routes available

Most clinical problems that you'll encounter will relate to administration of medicines into the gut ('enteral') or by injection but remember that there are other routes which you should not overlook. For example, the transdermal route can be a useful alternative if you are running out of suitable methods to give certain medicines (e.g. fentanyl patches for pain in a patient with dysphagia). Similarly, the inhaled route can be used to administer selected drugs other than bronchodilators and corticosteroids (e.g. antibiotics for cystic fibrosis, pentamidine for Pneumocystis jirovecii pneumonia).
Note that in many clinical situations in hospitals, the administration of medicines can involve unlicensed use. Although medicines cannot be promoted outside the limits of their marketing authorisation, the Human Medicines Regulations 2012 do not prohibit the use of unlicensed medicines. It is recognised that informed use of unlicensed medicines or of licensed medicines for unlicensed purposes (‘off-label’ use) is often necessary – particularly in paediatric patients.