A nurse's role is one of the most multifacted in the health industry, and one of the most critical parts of their day to day routine is the administering of medication to patients. 

Depending on the environment in which they work, nurses could be dealing with medication as often as every few minutes. That's why it's imperative nurses have a solid understanding of pharmacology, including potentially fatal drug interactions.

“The nurse’s role in administering medication in a hospital environment is broad,” says Registered Nurse and academic Dr Jessica Stokes-Parish.

“As a nurse you will check the medication dosing and administration route, amongst other things such as the time to be administered. A nurse can also ‘nurse-initiate; medications, such as paracetamol, in some facilities as they are deemed low-risk.

“What this means is a nurse can determine if the medication is appropriate and prescribe the medication for administration.”

Administering medication

The word ‘nurse’ can mean many things, including an Assistant in Nursing, an Enrolled or Endorsed Enrolled Nurse or Registered Nurse.

An Endorsed Enrolled Nurse and Registered Nurse can administer medications, says Dr Stokes-Parish, while an Enrolled Nurse can only do so if they have completed the relevant education.

“In some aged care facilities, Endorsed Assistants in Nursing are allowed to dispense medications from a Webster Pack,” says Dr Stokes-Parish.

“Some nurses may have restrictions on administration due to errors or infringements.”

Education around medication administration is a key part of nursing training, and refresher courses are available. 

“Medication competencies are a part of yearly assessments to provide you with refresher training on medication calculations and a variety of other things," says Dr Stokes-Parish.

While you aren’t expected to know every single medication off the top of your head, a basic understanding of the class of medications, the broad classification and knowing where to look to find important information is essential. 

“A good understanding of pharmacology is essential to the safe administration of medications."

Key questions nurses should be able to answer include:

• Why do medication errors occur?
• What are the contributing factors to medication errors?
• Which drug classes do I need to improve my knowledge of?
• What strategies could be implemented in the workplace to reduce error?

Dr Stokes-Parish says there are six key steps nurses need to take before they give the patient their medicine:

• Right Drug: double check the prescription, medication and expiry date on the medicine.
   
• Right Patient: confirm the patient by a minimum of two identifiers, such as their name and date of birth. Also ensure they have an understanding of what the medication is and any possible side effects.
   
• Right Dosage: confirm the dosage using a current drug reference. If unconfirmed, then calculate the dosage and double check with another nurse or doctor.
   
• Right Time: confirm how often the medicine is to be administered and check with the patient when they had their last dosage.
   
• Right Route: ensure the appropriateness of the route ordered and whether the patient can receive the medication from this route.
   
• Right Documentation: document the administration of the medication as soon as it has been administered. Using professional clinical software can guarantee consistency.

Drug-drug interactions

Drug interactions are a key consideration when administering a medication.  A drug interaction is where the active component of the medication might interfere or interact with another drug or product.

“If you have no knowledge of the medications and interactions, you are less likely to understand what a fatal drug interaction is,” says Dr Stokes-Parish.

“A good example is the interaction between clarithromycin and calcium-channel blockers (like amlodipine) - administering these together can cause hypotension and acute renal failure.”

While combining drugs in some instances isn't an issue, in a worst-case scenario, a patient could die. The risk increases with the number of medications. 

“Some drug interactions are beneficial. For example, in the case of paracetamol and oxycodone, the paracetamol enhances the uptake of oxycodone, making the pain relief more effective.”

There are a number of factors that might contribute to a nurse delivering the wrong medication.

The medication order may be hard to read, or a verbal order may have been interpreted incorrectly, which is why a second check is required for phone orders.

“Other errors are related to the medication and the packaging itself,” says Dr Stokes-Parish.

“Medicine cabinets are large, with high volumes of medication, which can make decision-making difficult.

“Some medication packaging is identical - there are frequently reported cases of ‘look alike, sound alike’ packaging issues. These errors are more likely to occur when you are time pressured and/or inexperienced with the medication you are administering.”

If you are pressed for time and the environment does not support good decision-making, you are likely to make a mistake.

What to do in an emergency

In the case of a negative drug interaction, follow the DRSABC algorithm - ensure the area is safe and that there is a response from your patient.

Send for help by notifying your senior staff and medical staff. If the patient is unconscious, then make a Medical Emergency Team (MET) call.

“Assess the airway, breathing and circulation and keep note of their function over a period of time,” says Dr Stokes-Parish.

“You may need to lodge an incident report, and you will need to document the event in the patient’s progress notes.”

Monitoring for adverse drug reactions

Along with medication administration and the detection of potentially fatal drug-drug interactions, nurses are heavily involved in many other medication-related activities.

“These include patient monitoring for both therapeutic effects of drugs and adverse drug reactions”, said Associate Professor Snezana Kusljic, pharmacologist and lead for pharmacology education at the University of Melbourne’s Department of Nursing.

“Thus, nurses must be equipped with extended pharmacology knowledge that will allow them to recognise therapeutic responses to drugs and adverse drug reactions to ensure patient safety and to respond to patients’ needs accordingly," Associate Professor Kusljic said.

"Adverse drug reactions can occur upon administration of a single medication at normal doses and unfortunately, these are not preventable as they are related to the intrinsic nature of a medication. For example, fluoroquinolones are associated with tendon inflammation, rupture or tearing and the risk of this reaction increases in patients who are over 60 years of age. Thus, it is important to know that age-dependent physiological changes can also alter response to a medication”, she said.

“Furthermore, understanding that there are different types of adverse drug reactions is critical for nursing practice. Predictable adverse drug reactions are the ones related to the normal pharmacological action of a drug, whereas unpredictable reactions are not related to the drug’s known activity and may be idiosyncratic, immunological, or allergic in nature.

“For example, administration of insulin to diabetic patients is aimed at decreasing blood glucose level and hence one of the predictable adverse drug reactions is hypoglycaemia. In contrast, nephrotoxicity that can develop in patients taking vancomycin is unpredictable as the target for vancomycin’s action is the bacterial cell and not the host/mammalian cell.”

Therapeutic effectiveness and pharmacogenomics

A/Professor Kusljic told HealthTimes that it was crucial for nurses to understand that some patients will require significant adjustments to a normal dose of the same medication, and some will not respond at all needing a completely different medication.

“The driving force behind medication therapeutic effectiveness has been attributed to genetic variations. Pharmacogenomics (PGx) is an arm of pharmacology in which an individual's genetic information is used to guide drug therapy for individual patients in terms of drug choice and dose selection.

“Having a sound understanding of PGx will empower nurses to request medication reviews more regularly and initiate discussions around PGx screen/testing”, explained A/Professor Kusljic.

For example, therapeutic response to warfarin is influenced by gene mutations in vitamin K epoxide reductase component 1 (VKORC1) and cytochrome P450 enzyme (CYP2C9) with more than 10-fold variability in doses required for optimal effects.

“This means that several doses of warfarin are commonly trialled before the right dose is found; the one that will produce therapeutic effect and minimise the incidence of adverse reactions,” said A/Professor Kusljic. 

“Additionally, 15% of clopidogrel is metabolised by CYP2C19 enzyme to an active compound that is responsible for its antiplatelet activity. Mutation in the CYP2C19 gene reduces antiplatelet activity causing variability in patients’ response to clopidogrel and hence can lead to serious and fatal outcomes.

“Therefore, integration of PGx education into nursing CPD hours is paramount as it will improve knowledge about genetic variations that influence a patient’s response which in turn will have an impact on patient safety.

“Having a highly skilled and confident nursing workforce that will be able to recognise and respond more effectively to genetically influenced responses to medications is central to the 21st century healthcare industry."

Improving knowledge of medication

As a health care provider, nurses have a duty to stay updated about medical advancements and pharmaceutical drugs.

“Make specific goals for your learning,” says Dr Stokes-Parish.

“If you have a particular area you want to improve in, focus on that with developing a specific outcome that you would like to achieve. Set a time frame to achieve this, and regularly check up on yourself."

Additional steps nurses can take to improve their knowledge include:

• Continue with education, with short courses that also provide contact hours and receive a Continuing Education Unit (CEU).
   
• Study drug information which can be accessed online and outlines precautions, side effects, interactions, dosage instructions, potential diagnoses a nurse can make and teachings for patients and carers.
   
• Access practice resources, such as practice guidelines and legal information, as well as text books which cover drug information, nursing skills in communication, and critical thinking.
   
• Increase their CPD hours, study online about drug interactions and administering medication successfully.
   
• Attend seminars aimed at nurses to update them about medicines.