Pharmacology — What You Need to Know as a Student Nurse
Standing at a drug trolley with a crowded prescription chart can feel overwhelming. Pharmacology is one of the most vital pillars of safe nursing care under the NMC Code. From understanding drug mechanisms to managing Controlled Drugs and recognising high-risk medications — here is your comprehensive guide, including the 20 most commonly prescribed drugs in the NHS.
“All substances are poisons; there is none which is not a poison. The right dose differentiates a poison from a remedy.”
1. The Two Pillars of Pharmacology
Before memorising specific drug names, every student nurse must understand the two basic principles governing how medicines interact with the human body: Pharmacokinetics and Pharmacodynamics.
🔄 Pharmacokinetics vs. Pharmacodynamics
This describes the journey of a medication through the body, defined by the four-stage ADME process:
- Absorption: How the drug enters the bloodstream (oral GI absorption vs. direct IV injection).
- Distribution: How the drug travels through fluids and tissues to reach its target site.
- Metabolism: How the liver breaks down the active drug compound (first-pass metabolism).
- Excretion: How the kidneys (or bowel/lungs) remove drug metabolites from the body.
💡 Clinical Pearl: Impaired renal or hepatic function leads to drug accumulation and toxicity. Always check renal markers (Creatinine/eGFR) before administering renally excreted drugs like Gentamicin or Digoxin!
This relates to biochemical and physiological effects on receptors, enzymes, or ion channels. Drugs act primarily as:
- Agonists: Bind to and activate a receptor (e.g., Salbutamol stimulating Beta-2 receptors in airways).
- Antagonists (Blockers): Bind and block activation (e.g., Bisoprolol blocking Beta-1 receptors in the heart).
2. Controlled Drugs & Legal Frameworks
Under the Misuse of Drugs Act 1971 and Misuse of Drugs Regulations 2001, Controlled Drugs are strictly regulated in the NHS. Understanding these rules protects your registration and your patients.
🔒 Schedule 2 Controlled Drugs — Golden Rules
- Storage: Double-locked steel cupboard, fixed securely to wall or floor.
- Keys: Held continuously by a designated Registered Nurse on duty.
- Double-check: Two qualified practitioners verify patient, drug, dose, route, time, expiry, and stock balance.
- CD Register: Bound book, ink entries, completed immediately. Any discrepancy reported to Charge Nurse at once.
- Wastage: Denatured in a CD destruction kit, witnessed by a second practitioner. Never down the sink or in general waste.
3. The 6 Rights of Medication Administration
Before giving any medicine alongside your Practice Supervisor, work through these systematically — every single time:
- Right Patient: Check wristband name, DOB, hospital number — ask them to state their full name.
- Right Drug: Check generic name against prescription + BNF. If you don’t recognise it — stop and check.
- Right Dose: Verify strength, units (mg vs micrograms), calculate independently.
- Right Route: Oral / IV / IM / SC / PR — matches exactly what is written.
- Right Time: Check frequency and when it was last given — prevent accidental overdose.
- Right Documentation: Sign after they have taken it — never before.
4. Top 20 Most Commonly Prescribed NHS Drugs
These are the ones you will see every shift. Know their class, what they do, and what to watch for — your confidence will grow with every drug round.
1. Paracetamol
Analgesic & AntipyreticUses: Mild–moderate pain, fever reduction.
Nursing checks: Standard dose 1g QDS — max 4g/24hrs. Reduce dose if under 50kg or severe liver impairment.
⚠️ Red Flag: Check for hidden paracetamol in co-codamol, tramacet etc. — accidental overdose causes fatal liver failure.
2. Morphine Sulfate
Opioid (Sch 2 CD)Uses: Severe pain, acute pulmonary oedema, end-of-life symptom control.
Nursing checks: Respiratory rate & sedation level before and after. Hold if RR < 10. Prescribe laxatives + antiemetics alongside.
⚠️ Antidote: Naloxone reverses opioid-induced respiratory depression.
3. Amoxicillin
Penicillin AntibioticUses: Chest, ear, urine, and respiratory infections.
Nursing checks: ALWAYS check allergy status first. Watch for diarrhoea — could be C. diff.
⚠️ Red Flag: Confirmed penicillin allergy = do not give — anaphylaxis risk.
4. Ramipril
ACE InhibitorUses: High BP, heart failure, post-MI, kidney protection in diabetes.
Nursing checks: Check BP before giving. Dry cough is a common side effect. Monitor U&Es — can raise potassium and affect kidney function.
⚠️ Hold if systolic BP < 90 mmHg or potassium > 5.5 mmol/L.
5. Bisoprolol
Beta-BlockerUses: High BP, angina, AF rate control, heart failure.
Nursing checks: Pulse and BP before every dose. Slows the heart — reduces its workload.
⚠️ Hold if HR < 50 bpm or BP < 90 systolic. Caution in asthma — can trigger bronchospasm.
6. Salbutamol
BronchodilatorUses: Asthma, COPD — opens airways. Also used in high-dose nebulised form for severe hyperkalaemia.
Nursing checks: Causes tremor, fast pulse, can lower potassium slightly. Reassess breathing 15 mins after nebuliser.
💡 Tip: Use a spacer with inhalers — more drug reaches the lungs, less hits the throat.
7. Metformin
Biguanide (Type 2 Diabetes)Uses: Lowers blood sugar — doesn’t cause hypos on its own.
Nursing checks: Give with or after food — reduces tummy upset.
⚠️ STOP before and for 48hrs after IV contrast scans — risk of lactic acidosis. Check renal function.
8. Atorvastatin
Statin — CholesterolUses: Lowers bad cholesterol — stabilises plaque so it doesn’t rupture. Prevents heart attack and stroke.
Nursing checks: Best taken at night — body makes most cholesterol then.
⚠️ Unexplained muscle pain or weakness — report promptly. Rare but serious breakdown of muscle tissue.
9. Furosemide
Loop DiureticUses: Removes excess fluid — swollen ankles, heart failure, pulmonary oedema.
Nursing checks: Weigh daily, monitor fluid balance, check BP. Watch potassium levels — drops fast.
⚠️ Dehydration + low potassium = falls risk, kidney strain. Encourage water unless restricted.
10. Omeprazole
Proton Pump InhibitorUses: Stops stomach acid — ulcers, reflux, protection on steroids/NSAIDs.
Nursing checks: Swallow whole — don’t crush the granules. Long-term use can lower magnesium and B12.
💡 Usually taken 30–60 mins before breakfast for best effect.
11. Enoxaparin (Clexane)
Blood Thinner — LMWHUses: Prevents and treats DVT/PE. Given after surgery to stop clots forming.
Nursing checks: Deep subcutaneous injection into tummy — don’t rub site afterwards. Leave the air bubble in the pre-filled syringe — it clears the needle.
⚠️ Watch for bleeding gums, bruising, black stools. Low platelet count needs checking.
12. Aspirin
AntiplateletUses: Prevents clots — 75mg daily protects against heart attack and stroke. 300mg given immediately in suspected heart attack.
Nursing checks: Give with food — irritates the stomach lining.
⚠️ Active stomach ulcer, bleeding disorders, severe asthma — do not give.
13. Warfarin
AnticoagulantUses: AF, mechanical valves, DVT/PE — stops dangerous clots forming inside the heart or veins.
Nursing checks: INR blood test guides the dose — target usually 2.0–3.0. Keep vitamin K intake consistent (leafy greens) — don’t suddenly eat lots or avoid completely.
⚠️ Antidote: Vitamin K reverses warfarin toxicity — but takes hours. Severe bleeding needs Prothrombin Complex Concentrate urgently.
14. Prednisolone
SteroidUses: Calms severe inflammation — asthma attacks, COPD, arthritis, IBD.
Nursing checks: Morning dose with breakfast — mimics natural body rhythm, reduces sleep disruption and stomach upset. Raises blood sugar in diabetics.
⚠️ Never stop suddenly after more than a few weeks — body stops making its own steroid. Tapering dose is vital.
15. Levothyroxine
Thyroid ReplacementUses: Underactive thyroid — controls metabolism, energy, temperature.
Nursing checks: First thing in the morning, empty stomach, wait 30–60 mins before food or other tablets — calcium and iron stop it being absorbed.
💡 Too much = fast pulse, weight loss, jitters. Too little = tired, cold, slow — blood tests adjust dose.
16. Co-codamol
Codeine + ParacetamolUses: Stronger pain relief when paracetamol alone isn’t enough.
Nursing checks: Number = codeine strength (8/500, 15/500, 30/500). 30/500 is Schedule 3 Controlled Drug. Causes constipation — prescribe laxative alongside.
⚠️ NEVER give extra paracetamol alongside — every tablet already contains 500mg. Risk of fatal liver overdose.
17. Sertraline
SSRI AntidepressantUses: Depression, anxiety, panic, OCD, PTSD.
Nursing checks: Doesn’t work instantly — 2–4 weeks to feel benefit. First few days can feel worse before better — explain this so they don’t stop.
⚠️ Agitation, fever, rigidity, confusion = serotonin syndrome — seek medical help immediately.
18. Amlodipine
Calcium Channel BlockerUses: High BP and angina — relaxes and widens blood vessels.
Nursing checks: Ankle swelling, flushed face, headache are common — usually settle after a few weeks. Check BP before giving.
⚠️ Hold if systolic BP < 90 mmHg — dizziness and falls risk.
19. Lorazepam
Benzodiazepine (Sch 4 CD)Uses: Severe agitation, acute anxiety, seizures — short-term only.
Nursing checks: Lowers breathing rate and consciousness. Monitor closely — especially with opioids.
⚠️ Antidote exists (Flumazenil) but rarely used — can trigger withdrawal seizures in regular users.
20. Gentamicin
IV Antibiotic — Severe InfectionUses: Serious infection — sepsis, kidney infection, endocarditis.
Nursing checks: Slow IV infusion over 30–60 mins. Blood levels MUST be checked — dose adjusted carefully.
⚠️ Can damage hearing permanently and affect kidneys. Tinnitus or dizziness = report immediately.
Final Thoughts — Never Be Afraid to Ask
No nurse knows every drug in the BNF by heart. Safe practice isn’t about instant recall — it’s knowing where to look it up and having the confidence to say “I’d like to double-check that”.
Use the BNF, ask the pharmacist, verify with your supervisor — every single time. Those checks aren’t red tape — they’re what keep patients safe and what will keep you a confident, compassionate nurse for your whole career.
Written by: Daniel Hancock, Registered Nurse
Focus: Safe medication administration, drug awareness, ward pharmacology
Published: September 2026 | Last reviewed: September 2026
For: UK student nurses — supervised learning only
⚠️ Always cross-reference with the British National Formulary (BNF) and local hospital policy. This guide supports learning — it does not replace professional clinical judgement or the BNF. When in doubt — check.