From the previous chapters you will see that understanding the pharmacological aspects of the drugs you are administering is vital to keeping your patients safe. Nurses need to understand the pharmacodynamics of a medicine, or how it actually works within the body, since this will need to be explained to patients and carers. For example, how will you ensure that a patient understands the importance of taking their treatment for hypertension (especially if they are experiencing no symptoms) if you are unable to explain how the medicine will be working? Similarly, your understanding of the pharmacokinetics (the absorption, distribution, metabolism, and excretion) of individual medicines is vital to ensure compromised patients are not administered inappropriate medicines. For example, you would question the prescribing of a non-steroidal anti-inflammatory drug (NSAID) to a patient with significant renal impairment, because the kidney is essential to the elimination of NSAIDs so the drug could accumulate if the kidneys are not functioning properly. From the point of view of ensuring patient safety, you will need to understand the principles of drug interactions so that you can understand how two medicines (or food and medicine) could interact and be alert to signs that this may be happening. There are several good textbooks dealing with the uses and actions of individual medicines, including interactions. However, these will not be discussed here because at this stage of your career you are not expected to have a detailed knowledge of particular medicines, but rather an understanding of the key principles. As nurses, we are concerned with how the body handles medicines (pharmacokinetics) so that we can see how this may be affected by age, genetics, or illness, and how the actions of medicines may conflict with one another or produce toxicity because their effects are additive. Equally, we need to look at occasions in which two medicines produce the same response by two different routes; such interactions can be beneficial to the patient and avoid having to give large doses of a single medicine because the same result can be achieved with smaller doses of two medicines, thereby reducing the risk of adverse effects.
Effects of renal impairment on transporter-mediated renal reabsorption of drugs and renal drug-drug interactions: A simulation-based study