Introduction
The non-medical prescribing exam tests candidates’ knowledge and skills in key areas required for safe and effective prescribing practice. This guide covers three major components of the exam: pharmacology, drug calculations, and legal/ethical aspects of prescribing. For each section, we’ll review key concepts and provide example questions with detailed explanations.
Pharmacology
Pharmacology forms a core part of the non-medical prescribing exam. Candidates need to demonstrate understanding of drug actions, interactions, adverse effects, and considerations for different patient groups.
Key pharmacology concepts to review:
- Pharmacokinetics (absorption, distribution, metabolism, excretion)
- Pharmacodynamics (drug-receptor interactions, dose-response)
- Drug interactions and contraindications
- Adverse drug reactions and side effects
- Special considerations for pediatric, geriatric, and pregnant patients
- Common drug classes and their mechanisms of action
Example Questions:
- Which of the following is an example of a type A (augmented) adverse drug reaction?
a) Anaphylaxis after penicillin b) Drowsiness from an antihistamine
c) Stevens-Johnson syndrome from a sulfonamide d) Aplastic anemia from chloramphenicol
Answer: B – Drowsiness from an antihistamine
Explanation: Type A adverse drug reactions are predictable and dose-related, resulting from the known pharmacological action of the drug. Drowsiness is a common, predictable side effect of many antihistamines due to their action on histamine receptors in the brain. The other options are examples of type B (bizarre or idiosyncratic) reactions, which are unpredictable and not related to the drug’s known pharmacological actions.
- A 70-year-old patient with hypertension and type 2 diabetes is prescribed ramipril. What electrolyte should be monitored closely in this patient?
a) Sodium b) Potassium
c) Calcium d) Magnesium
Answer: B – Potassium
Explanation: ACE inhibitors like ramipril can cause hyperkalemia, especially in older adults and those with diabetes or renal impairment. This is due to the drug’s effect on the renin-angiotensin-aldosterone system, which reduces aldosterone production and potassium excretion. Regular monitoring of serum potassium is important in patients taking ACE inhibitors, particularly those with risk factors for hyperkalemia.
- Which of the following drug pairs demonstrates a pharmacokinetic interaction?
a) Warfarin and aspirin b) Digoxin and amiodarone
c) ACE inhibitor and angiotensin receptor blocker d) Beta-blocker and calcium channel blocker
Answer: B – Digoxin and amiodarone
Explanation: This is an example of a pharmacokinetic interaction. Amiodarone inhibits P-glycoprotein, a transport protein involved in digoxin elimination, leading to increased digoxin levels. This interaction occurs at the level of drug elimination (pharmacokinetics). The other options are examples of pharmacodynamic interactions, where drugs affect the same physiological system.
- A patient is prescribed clarithromycin for a respiratory infection. Which of the following drugs should be used with caution due to a potential interaction?
a) Omeprazole b) Simvastatin
c) Metformin d) Levothyroxine
Answer: B – Simvastatin
Explanation: Clarithromycin is a strong inhibitor of CYP3A4, an enzyme involved in the metabolism of many drugs, including simvastatin. Co-administration can lead to significantly increased simvastatin levels, increasing the risk of myopathy and rhabdomyolysis. This interaction highlights the importance of understanding common drug-drug interactions and the role of cytochrome P450 enzymes in drug metabolism.
Drug Calculations
Accurate drug calculations are crucial for safe prescribing. The exam will likely include questions on dosage calculations, unit conversions, and interpreting drug concentrations.
Key calculation skills to practice:
- Converting between units (e.g., mg to g, mL to L)
- Calculating doses based on patient weight
- Determining infusion rates
- Adjusting doses for renal impairment
- Understanding and using different concentration expressions (e.g., %, mg/mL)
Example Questions:
- A child weighing 25 kg is prescribed amoxicillin at a dose of 40 mg/kg/day in three divided doses. The available suspension is 250 mg/5 mL. How many mL should be given per dose?
Step 1: Calculate the total daily dose 40 mg/kg/day × 25 kg = 1000 mg/day
Step 2: Calculate the dose per administration (three times daily) 1000 mg ÷ 3 = 333.33 mg per dose
Step 3: Convert the dose to mL using the available concentration 333.33 mg × (5 mL / 250 mg) = 6.67 mL
Answer: 6.67 mL (rounded to 6.7 mL for practical administration)
- An IV infusion contains 1 g of drug in 500 mL of solution. Express this as a percentage concentration.
Step 1: Convert 1 g to mg 1 g = 1000 mg
Step 2: Calculate mg/mL concentration 1000 mg / 500 mL = 2 mg/mL
Step 3: Convert to percentage (remember that 1% = 1 g / 100 mL = 10 mg/mL) 2 mg/mL = 0.2%
Answer: 0.2%
- A patient with renal impairment (creatinine clearance 30 mL/min) requires gentamicin. The normal dose is 5-7 mg/kg every 24 hours. If you decide to give 5 mg/kg, what percentage of the normal dose should be given?
For creatinine clearance 30-59 mL/min, the recommended dose is 60% of normal dose every 24 hours.
Answer: 60% of the normal dose
- A patient is prescribed morphine sulfate 10 mg IV every 4 hours as needed for pain. The available concentration is 10 mg/mL. How many mL should be administered for each dose?
10 mg ÷ (10 mg/mL) = 1 mL
Answer: 1 mL
Legal and Ethical Aspects
Understanding the legal and ethical framework of prescribing is essential for safe and professional practice. This section may cover topics such as consent, capacity, prescribing legislation, and professional responsibilities.
Key legal and ethical concepts:
- Controlled drug regulations
- Prescribing for children and vulnerable adults
- Informed consent and mental capacity
- Professional accountability and scope of practice
- Prescribing documentation and record-keeping
- Off-label and unlicensed prescribing
Example Questions:
- A nurse independent prescriber wants to prescribe a controlled drug for a patient with chronic pain. Which schedule of controlled drugs can they legally prescribe from?
a) Schedule 1 only b) Schedules 2 and 3 only c) Schedules 2, 3, 4, and 5
d) They cannot prescribe any controlled drugs
Answer: C – Schedules 2, 3, 4, and 5
Explanation: As of 2012, nurse independent prescribers in the UK can prescribe any controlled drug listed in Schedules 2, 3, 4, and 5 of the Misuse of Drugs Regulations for any medical condition within their competence, with the exception of cocaine, diamorphine and dipipanone for the treatment of addiction.
- When prescribing for a 15-year-old patient, which of the following is true regarding consent?
a) Consent must always be obtained from a parent or guardian b) The patient can consent if deemed Gillick competent
c) Consent is not required for patients under 16 d) Only a court can determine if the patient can consent
Answer: B – The patient can consent if deemed Gillick competent
Explanation: The concept of Gillick competence applies to patients under 16. If a young person is deemed to have sufficient understanding and intelligence to comprehend fully what is proposed (Gillick competent), they can give consent to treatment. This assessment is made on a case-by-case basis and depends on the maturity of the patient and the complexity of the treatment.
- A pharmacist independent prescriber wants to prescribe an unlicensed medication for a patient. Which of the following statements is correct?
a) Unlicensed medications can never be prescribed by non-medical prescribers b) Unlicensed medications can only be prescribed as part of a clinical trial c) Unlicensed medications can be prescribed if it’s in the patient’s best interest and no licensed alternative is available
d) Unlicensed medications can only be prescribed with permission from the medicines regulatory agency
Answer: C – Unlicensed medications can be prescribed if it’s in the patient’s best interest and no licensed alternative is available
Explanation: Non-medical prescribers, including pharmacist independent prescribers, can prescribe unlicensed medications if it’s in the best interest of the patient and there’s no suitable licensed alternative. However, they must be able to justify their decision and should inform the patient that the medication is unlicensed.
- Which of the following is NOT a legal requirement for a prescription?
a) Name and address of the patient b) Name and signature of the prescriber c) Date of prescription d) Diagnosis of the patient
Answer: D – Diagnosis of the patient
Explanation: While including the diagnosis can be helpful, it is not a legal requirement for a prescription. The legal requirements include the patient’s name and address, the name and signature of the prescriber, and the date of the prescription. For controlled drugs, additional requirements include the dose, form, and total quantity of the drug in both words and figures.
- A nurse wants to administer a medication to a patient who lacks capacity to consent. Under what circumstances can this be done legally?
a) It can never be done without the patient’s consent b) It can be done if it’s in the patient’s best interests and complies with the Mental Capacity Act
c) It can only be done with a court order d) It can be done if two healthcare professionals agree it’s necessary
Answer: B – It can be done if it’s in the patient’s best interests and complies with the Mental Capacity Act
Explanation: The Mental Capacity Act 2005 provides a framework for making decisions on behalf of people who lack capacity. Treatment can be given without consent if it’s in the patient’s best interests and the least restrictive option. This decision should be made after considering the patient’s past and present wishes, beliefs, and values, and consulting with others involved in their care.
Additional Pharmacology Topics
Drug-Drug Interactions Understanding drug-drug interactions is crucial for safe prescribing. These interactions can be pharmacokinetic (affecting absorption, distribution, metabolism, or excretion) or pharmacodynamic (affecting the drug’s mechanism of action).
Example Question:
- Which of the following combinations presents a potentially dangerous pharmacodynamic interaction?
a) Omeprazole and diazepam b) Warfarin and amiodarone c) Digoxin and verapamil d) Fluoxetine and tramadol
Answer: D – Fluoxetine and tramadol
Explanation: This combination presents a risk of serotonin syndrome. Fluoxetine, an SSRI, increases serotonin levels. Tramadol, besides its opioid effects, also has serotonergic activity. The combination can lead to excessive serotonin activity, potentially causing a life-threatening condition. This illustrates the importance of understanding both the primary and secondary pharmacological actions of drugs.
Pharmacokinetics in Special Populations
Prescribers must understand how drug handling changes in different patient groups, particularly in older adults, children, and patients with renal or hepatic impairment.
Example Question:
- Which of the following statements about drug pharmacokinetics in older adults is correct?
a) Drug absorption is always increased b) Drug distribution is unaffected by age-related changes c) Hepatic metabolism is generally reduced d) Renal excretion is typically enhanced
Answer: C – Hepatic metabolism is generally reduced
Explanation: Aging is associated with a reduction in liver mass and hepatic blood flow, which can lead to decreased hepatic metabolism of drugs. This can result in higher plasma concentrations of drugs metabolized by the liver, potentially increasing the risk of adverse effects. Prescribers should consider starting with lower doses and titrating carefully in older adults for drugs primarily metabolized by the liver.
Additional Drug Calculations Topics
Dose Adjustments in Renal Impairment
Many drugs require dose adjustments in patients with renal impairment. Understanding how to calculate these adjustments is crucial for safe prescribing.
Example Question:
- A patient with a creatinine clearance of 25 mL/min requires gentamicin. The normal dose is 5-7 mg/kg every 24 hours. If you decide to give 5 mg/kg, what dosing interval should be used?
a) Every 12 hours b) Every 24 hours c) Every 36 hours d) Every 48 hours
Answer: C – Every 36 hours
Explanation: For patients with creatinine clearance between 20-40 mL/min, the recommended dosing interval for gentamicin is every 36 hours. This extended interval allows more time for drug elimination, reducing the risk of accumulation and toxicity in patients with impaired renal function.
Calculation of Infusion Rates
Intravenous drug administration often requires calculation of infusion rates.
Example Question:
- A patient is prescribed dopamine at 5 mcg/kg/min. The patient weighs 70 kg. The available preparation is 400 mg dopamine in 500 mL 5% glucose. What should the infusion rate be in mL/hour?
Step 1: Calculate the dose per hour 5 mcg/kg/min × 70 kg × 60 min = 21,000 mcg/hour = 21 mg/hour
Step 2: Calculate the concentration of the infusion 400 mg / 500 mL = 0.8 mg/mL
Step 3: Calculate the infusion rate 21 mg/hour ÷ 0.8 mg/mL = 26.25 mL/hour
Answer: 26.25 mL/hour (rounded to 26.3 mL/hour for practical administration)
Additional Legal and Ethical Topics
Prescribing Errors and Accountability
Prescribing errors can have serious consequences. Non-medical prescribers must understand their accountability and the steps to take when errors occur.
Example Question:
- A nurse prescriber realizes they have made a prescribing error. What should be their immediate action?
a) Ignore it if no harm has come to the patient b) Inform the patient and take steps to rectify the error c) Ask a colleague to correct the error without informing anyone else d) Wait until the next medication review to address the issue
Answer: B – Inform the patient and take steps to rectify the error
Explanation: When a prescribing error is identified, the prescriber has a professional and ethical duty to be open and honest about the error (duty of candour). They should inform the patient, apologize, explain what happened, and take immediate steps to rectify the error and prevent harm. The incident should also be reported through appropriate channels for learning and improving patient safety.
Prescribing for Yourself or Family Members
Ethical considerations around prescribing for oneself or family members are important to understand.
Example Question:
- In which of the following situations might it be acceptable for a non-medical prescriber to prescribe for a family member?
a) Routine prescription of oral contraceptives for their daughter b) Antibiotics for their spouse’s suspected chest infection c) Emergency treatment of anaphylaxis while on holiday d) Regular prescribing of antihypertensive medication for their parent
Answer: C – Emergency treatment of anaphylaxis while on holiday
Explanation: Generally, prescribing for family members is discouraged due to potential conflicts of interest and lack of objectivity. However, in genuine emergencies where no other prescriber is available and delay could cause serious harm, it may be acceptable. In this case, treating anaphylaxis (a life-threatening condition) while on holiday, when other medical care may not be immediately available, could be justified. The prescriber should document the circumstances thoroughly and arrange proper follow-up care as soon as possible.
Key points to remember:
- Pharmacology: Understand drug actions, interactions, and effects in different patient populations. Be familiar with common drug classes and their mechanisms of action.
- Drug Calculations: Practice a variety of calculations, including dose adjustments, concentration conversions, and infusion rates. Always check your work and consider the clinical reasonableness of your answer.
- Legal and Ethical Aspects: Know the limits of your prescribing authority, understand consent and capacity issues, and be familiar with the legal requirements for prescriptions. Always consider the ethical implications of your prescribing decisions.
- Patient Safety: This should be at the forefront of all prescribing decisions. Consider potential adverse effects, interactions, and the individual patient’s circumstances.
- Evidence-Based Practice: Stay up-to-date with current guidelines and best practices in your area of prescribing.
- Professional Development: Prescribing is a significant responsibility. Commit to ongoing learning and development to maintain and enhance your prescribing skills.
- Reflection and Learning: Use case studies and real-life scenarios to reflect on prescribing decisions and learn from both successes and challenges.
Conclusion
Success in the non-medical prescribing exam requires a solid understanding of pharmacology, proficiency in drug calculations, and knowledge of the legal and ethical framework of prescribing. Regular practice with a variety of question types and scenarios will help build confidence and competence. Remember to always consider patient safety, evidence-based practice, and professional accountability in your approach to prescribing.
This guide provides a starting point for exam preparation, but it’s important to thoroughly review all areas of the curriculum and seek clarification on any unclear concepts. Good luck with your studies and future prescribing practice!