OSCE Pharmacology and Medication Administration Flashcards

What are the 'Five Rights' of medication administration?

Answer: Right patient, right drug, right dose, right route, right time

The Five Rights are the foundational framework for safe medication administration: confirming the correct patient receives the correct drug at the correct dose by the correct route at the correct time.

A prescription reads 'paracetamol 1g PO QDS PRN.' What does 'QDS PRN' mean?

Answer: Four times daily as required (when needed)

QDS = quater die sumendus (four times daily); PRN = pro re nata (as required/when needed). Together they mean the drug can be given up to four times per day but only when the patient requires it.

When preparing to administer an intramuscular (IM) injection, which site is generally preferred in adults for volumes up to 3 mL?

Answer: Ventrogluteal (gluteus medius) — preferred for most IM injections in adults

The ventrogluteal site (hand placement landmark method) is preferred for IM injection in adults due to its large muscle mass, absence of major nerves/vessels, and low complication rate.

Which vital sign change should trigger withholding digoxin and contacting the prescriber?

Answer: Heart rate below 60 beats per minute (bradycardia)

Digoxin slows heart rate via vagal effects; administration when the heart rate is already below 60 bpm risks worsening bradycardia and potentially fatal arrhythmias.

What is the purpose of a 'drug allergy alert' documentation in a patient's medication record?

Answer: To prevent the patient from receiving any drug in the same class as the allergen, preventing potentially life-threatening reactions

Allergy documentation records the specific allergen and reaction type (severity) so that cross-reactive drugs and the allergen itself are avoided, preventing anaphylaxis and severe hypersensitivity reactions.

When administering IV medication, which step is essential to prevent air embolism?

Answer: Priming (flushing) the IV line to remove all air bubbles before connecting to the patient

Air embolism can cause cardiac arrest; priming the IV giving set eliminates air from the line before connection to the patient, a mandatory safety step.

A patient is prescribed warfarin. Which blood test is routinely monitored to guide dose adjustment?

Answer: INR (International Normalised Ratio)

The INR measures the effect of warfarin on clotting; doses are adjusted to maintain the INR within the therapeutic range (typically 2–3 for most indications).

Which medication requires checking blood glucose before administration?

Answer: Insulin

Insulin lowers blood glucose; the current blood glucose level must be measured before administration to determine the correct dose and prevent hypoglycaemia.

What does 'first-pass metabolism' mean, and which route of administration avoids it?

Answer: First-pass metabolism is the biotransformation of orally absorbed drugs by the liver before reaching systemic circulation; sublingual/intravenous routes bypass it

Oral drugs are absorbed through the GI tract and must pass through the portal circulation and liver, where they are metabolized before reaching systemic circulation — this reduces bioavailability; IV and sublingual routes bypass the liver.

A patient develops a widespread urticarial rash and throat tightness 10 minutes after receiving IV amoxicillin. What is the immediate priority action?

Answer: Stop the amoxicillin infusion and administer IM adrenaline (epinephrine) 0.5 mg (1:1000) immediately — this is anaphylaxis

Throat tightness and urticaria following antibiotic administration = anaphylaxis. Immediate IM adrenaline is the first-line treatment — no other intervention takes priority.

What is the correct action if a medication error (administering the wrong dose) is discovered after the medication has been given?

Answer: Immediately assess the patient for adverse effects, report to the senior clinician and prescriber, document accurately in the patient record, and complete an incident report

Patient safety requires immediate assessment, transparent disclosure, escalation to the clinical team, accurate documentation, and incident reporting — concealment constitutes professional misconduct.

Which electrolyte abnormality potentiates digoxin toxicity?

Answer: Hypokalaemia (low potassium)

Low potassium increases the risk of digoxin toxicity because potassium and digoxin compete for the same binding site on the Na+/K+ ATPase pump — less potassium means more digoxin effect.

What is the correct injection angle for a subcutaneous (SC) injection?

Answer: 45° angle in lean patients and 90° angle in patients with adequate subcutaneous tissue

SC injections are given at 45° in thin/lean patients to avoid hitting muscle; in patients with adequate subcutaneous tissue, 90° may be used. The needle should reach subcutaneous fat, not muscle.

Which pain scale is most appropriate for assessing pain in an unconscious or non-verbal patient?

Answer: Behavioural pain scale (BPS) or critical care pain observation tool (CPOT) — observe facial expression, limb movement, and ventilator compliance

Non-verbal pain scales (BPS, CPOT) use observable behavioural indicators to assess pain in patients unable to self-report — mandatory for ICU/sedated patients.

A patient is prescribed methotrexate once weekly. Why is the once-weekly schedule critical to follow exactly?

Answer: Methotrexate taken daily instead of weekly causes life-threatening bone marrow suppression and mucosal toxicity — it is one of the most dangerous prescribing errors in the UK

Daily methotrexate (instead of weekly) causes fatal bone marrow suppression and mucositis — methotrexate prescribing errors are a persistent patient safety issue causing preventable deaths in the UK.

What is the correct disposal method for unused controlled drugs (CDs) in a clinical setting?

Answer: Render them irretrievable in a CD denaturing kit in the presence of two authorised witnesses, then dispose as clinical waste

Controlled drugs must be denatured (rendered unusable) in the presence of two witnesses and documented in the CD register — strict regulations prevent diversion and misuse.

Which patient parameter is most important to check before administering an angiotensin-converting enzyme (ACE) inhibitor such as ramipril?

Answer: Blood pressure and renal function (serum creatinine/eGFR) and serum potassium

ACE inhibitors lower blood pressure and can cause hypotension, renal impairment, and hyperkalaemia — pre-dose BP, renal function, and potassium levels must be checked.

During an OSCE medication reconciliation station, what is the primary goal of medicines reconciliation?

Answer: To create an accurate, complete list of a patient's current medications at each transition of care to prevent omissions, duplications, and errors

Medicines reconciliation obtains a complete, accurate medication history at admission, transfer, and discharge to prevent medication errors at care transitions — a major source of preventable patient harm.

What is 'therapeutic drug monitoring' (TDM) and for which type of drug is it most important?

Answer: Regular measurement of serum drug levels to ensure concentrations are within the therapeutic range — most critical for drugs with narrow therapeutic indices such as vancomycin, digoxin, phenytoin, and lithium

TDM is used for drugs where therapeutic efficacy and toxicity are closely related to serum concentration — narrow therapeutic index drugs require regular blood level monitoring.

A patient's prescription states 'metformin 500 mg PO BD with food.' Why is 'with food' included in the instructions?

Answer: Metformin taken with meals reduces GI side effects (nausea, diarrhoea, abdominal discomfort) without affecting its blood glucose-lowering efficacy

Metformin commonly causes GI side effects; administration with or after meals significantly reduces nausea and diarrhoea without affecting its pharmacological effectiveness.