Top 50 Emergency Drugs for FRCEM
TL;DR — The 50 ED drugs FRCEM tests most: vasoactive, RSI, analgesia, sedation, paediatric resus, anti-arrhythmic, anti-epileptic, antidotes — dose, indication, pitfalls.
Last updated: 30 May 2026
Emergency pharmacology is examined repeatedly in MRCEM SBA, FRCEM SBA and FRCEM OSCE. Candidates are rarely tested on isolated drug facts. They are tested on choosing the right drug, in the right patient, by the right route, at the right time, while avoiding the dangerous alternative. In the emergency department, the same principles matter even more.
A useful revision approach is to learn drugs by scenario rather than alphabetically: cardiac arrest, peri-arrest arrhythmia, anaphylaxis, status epilepticus, procedural sedation, sepsis, toxicology, acute coronary syndrome, hyperkalaemia and major haemorrhage. That mirrors both real ED practice and exam design.
The 50 drugs covered here are: adrenaline, noradrenaline, amiodarone, lidocaine, magnesium sulphate, atropine, adenosine, calcium chloride, calcium gluconate, sodium bicarbonate, aspirin, glyceryl trinitrate, clopidogrel, ticagrelor, heparin, tenecteplase, furosemide, ketamine, propofol, midazolam, lorazepam, diazepam, fentanyl, morphine, paracetamol, ibuprofen, ondansetron, metoclopramide, haloperidol, droperidol, salbutamol, ipratropium, hydrocortisone, dexamethasone, ceftriaxone, piperacillin-tazobactam, gentamicin, vancomycin, aciclovir, naloxone, flumazenil, digoxin-specific antibody fragments, activated charcoal, N-acetylcysteine, insulin with dextrose, glucagon, levetiracetam, phenytoin or fosphenytoin, valproate and tranexamic acid.
Doses and pathways vary slightly by local formulary, specialty ownership and patient factors. For exams, use mainstream UK practice aligned with Resuscitation Council UK, RCEM, NICE, BTS/SIGN, TOXBASE and standard NHS pathways. In clinical work, always check local guidance, especially for antimicrobials, sedation and toxicology.
Why These Drugs Matter for FRCEM
Drug errors in emergency medicine are usually errors of context rather than memory. Common examples include:
- giving adrenaline too early in shockable arrest
- using IV adrenaline in routine anaphylaxis
- giving adenosine to an irregular broad-complex tachycardia
- forgetting that calcium stabilises the myocardium but does not lower potassium
- delaying second-line treatment in status epilepticus
- over-reversing an opioid-dependent patient with naloxone
- using flumazenil in mixed overdose or benzodiazepine dependence
These are classic SBA traps and real ED hazards. Strong candidates know indication, route, dose, sequence, contraindications, monitoring and escalation.
Key Definitions
- First-line drug: the standard initial treatment in a given scenario.
- Alternative drug: used when first-line treatment is unavailable, contraindicated or has failed.
- Peri-arrest: critically unwell with imminent risk of cardiac arrest.
- Shockable arrest rhythm: ventricular fibrillation or pulseless ventricular tachycardia.
- Non-shockable arrest rhythm: pulseless electrical activity or asystole.
- Status epilepticus: prolonged seizure activity or recurrent seizures without recovery; in practice, treat early and escalate promptly.
- Procedural sedation: use of sedative and analgesic drugs to facilitate painful or distressing procedures with full monitoring and airway readiness.
- Membrane stabilisation in hyperkalaemia: IV calcium to reduce arrhythmic risk; it does not remove potassium.
- Toxidrome: a recognisable pattern of poisoning features suggesting a drug class.
Essential Pathophysiology
Most emergency drugs are easiest to remember if linked to the physiological problem they correct.
- Adrenaline increases coronary and cerebral perfusion in arrest and reverses vasodilation and bronchospasm in anaphylaxis.
- Amiodarone and lidocaine suppress refractory ventricular arrhythmia in shockable arrest.
- Adenosine transiently blocks AV nodal conduction and terminates AV node-dependent SVT.
- Atropine reduces vagal influence and may improve symptomatic bradycardia.
- Calcium stabilises the cardiac membrane in hyperkalaemia.
- Insulin with dextrose shifts potassium intracellularly.
- Magnesium treats torsades de pointes and has roles in severe asthma and eclampsia.
- Benzodiazepines enhance GABA activity and terminate seizures.
- Ketamine provides dissociative sedation and analgesia while usually preserving airway reflexes better than many alternatives.
- Naloxone reverses opioid-induced respiratory depression.
- N-acetylcysteine replenishes glutathione and limits paracetamol hepatotoxicity.
- Tranexamic acid reduces fibrinolysis in major haemorrhage.
Clinical Presentation
The same drug may appear in very different presentations. High-yield ED scenarios include:
- persistent VF after the third shock
- anaphylaxis with wheeze, stridor or hypotension
- stable regular narrow-complex tachycardia
- symptomatic bradycardia with hypotension or syncope
- hyperkalaemia with ECG changes
- status epilepticus with or without IV access
- agitated trauma patient requiring procedural sedation
- opioid overdose with reduced respiratory rate
- paracetamol overdose
- sepsis or suspected meningitis
- STEMI, ACS or acute pulmonary oedema
- major trauma or postpartum haemorrhage
Red Flags and High-Risk Features
- airway compromise, stridor, severe bronchospasm or shock in anaphylaxis
- persistent VF/pulseless VT after three shocks
- irregular broad-complex tachycardia
- complete heart block or unstable bradycardia
- hyperkalaemia with ECG changes
- ongoing seizure beyond first-line benzodiazepine therapy
- reduced GCS with respiratory depression
- suspected TCA toxicity with QRS widening
- digoxin toxicity with arrhythmia or hyperkalaemia
- severe sepsis, meningococcal disease or suspected encephalitis
- major haemorrhage or haemodynamic instability
Differential Diagnosis
Drug choice depends on correct syndrome recognition.
- SVT versus atrial fibrillation versus VT
- anaphylaxis versus isolated urticaria versus asthma
- opioid overdose versus hypoglycaemia versus intracranial event
- status epilepticus versus psychogenic non-epileptic seizure
- hyperkalaemia versus broad-complex rhythm from another cause
- septic shock versus cardiogenic shock versus haemorrhagic shock
- TCA overdose versus sodium channel blocker toxicity from another agent
- agitated delirium versus psychosis versus hypoxia versus hypoglycaemia
Initial ED Assessment
Before any emergency drug, apply an ABCDE approach.
- Airway: patency, suction, adjuncts, need for RSI or anaesthetic support.
- Breathing: respiratory rate, oxygen saturation, work of breathing, capnography where relevant.
- Circulation: pulse, blood pressure, ECG, IV/IO access, shock state, haemorrhage.
- Disability: GCS, pupils, glucose, seizure activity, agitation.
- Exposure: rash, trauma, temperature, track marks, toxidrome clues.
Immediate bedside actions often run in parallel with drug treatment:
- defibrillation in shockable arrest
- oxygen only when indicated, not automatically in all ACS patients
- ECG before and after arrhythmia treatment where possible
- glucose in any reduced consciousness or seizure
- senior help early for sedation, toxicology, peri-arrest care and unstable arrhythmia
Investigations
- 12-lead ECG
- venous or arterial blood gas including potassium and lactate
- capillary blood glucose
- FBC, U&Es, renal function, LFTs, CRP
- troponin where indicated
- paracetamol level, salicylate level and other toxicology tests as indicated
- blood cultures before antibiotics if this does not delay treatment
- pregnancy test where relevant
- CXR, CT, CT head or CT aortogram depending on presentation
- drug levels where useful, for example digoxin
Management in the Emergency Department
Use a scenario-based framework. For each drug, know indication, adult dose, route, major cautions and what to do next if it fails.
1. Cardiac arrest and peri-arrest drugs
| Drug | Main indication | Typical adult dose | Key exam point |
|---|---|---|---|
| Adrenaline | Cardiac arrest; anaphylaxis | Arrest: 1 mg IV/IO of 1:10,000 every 3-5 min. Anaphylaxis: 500 micrograms IM of 1:1000, repeat after 5 min if needed | Do not confuse arrest and anaphylaxis dose, route or concentration |
| Amiodarone | Refractory VF/pulseless VT | 300 mg IV/IO after 3rd shock, then 150 mg after 5th shock | Only for shockable arrest rhythms |
| Lidocaine | Alternative to amiodarone in refractory VF/pVT | 100 mg IV/IO after 3rd shock, then 50 mg after 5th shock | Alternative, not routine addition to amiodarone |
| Magnesium sulphate | Torsades de pointes; severe asthma; eclampsia | 2 g IV | Think torsades, not generic arrest drug |
| Atropine | Symptomatic bradycardia | 500 micrograms IV, repeat every 3-5 min to 3 mg | Do not delay pacing or vasoactive support if unstable |
| Adenosine | Stable regular narrow-complex SVT | 6 mg rapid IV, then 12 mg, then 12 mg if needed | Avoid in irregular broad-complex tachycardia and pre-excited AF |
| Noradrenaline | Vasopressor for shock, usually septic shock | Infusion via pump, dose titrated to MAP and perfusion | Not a push-dose routine ED drug; needs monitoring and usually central access |
Adrenaline
- Cardiac arrest: 1 mg IV/IO of 1:10,000.
- Non-shockable arrest: give as soon as access obtained.
- Shockable arrest: give after the third shock, then every 3-5 minutes.
- Anaphylaxis: 500 micrograms IM of 1 mg/mL (1:1000) into the anterolateral thigh. Repeat after 5 minutes if needed.
- IV adrenaline in anaphylaxis is reserved for experienced clinicians with full monitoring in refractory shock/peri-arrest settings.
- Exam trap: route and concentration change completely with indication.
Amiodarone
- Persistent VF/pulseless VT: 300 mg IV/IO after the third shock.
- If still refractory: 150 mg IV/IO after the fifth shock.
- Not for asystole or PEA.
- Caution: hypotension and bradycardia, especially outside arrest.
Lidocaine
- Alternative antiarrhythmic if amiodarone is unavailable or unsuitable.
- 100 mg IV/IO after the third shock, then 50 mg after the fifth shock if needed.
- Do not routinely combine with amiodarone in the same arrest algorithm.
Magnesium sulphate
- Torsades de pointes: 2 g IV.
- In a perfusing patient, often infused over 10-15 minutes.
- In arrest or peri-arrest, may be given more rapidly.
- Also used in severe or life-threatening asthma and in eclampsia.
Atropine
- Symptomatic bradycardia: 500 micrograms IV, repeated every 3-5 minutes to a total of 3 mg.
- Less likely to work in high-grade AV block, infranodal disease or transplanted heart.
- If ineffective or patient remains unstable, escalate early to pacing and/or vasoactive support such as adrenaline infusion according to local peri-arrest guidance.
Adenosine
- Use after vagal manoeuvres for stable regular narrow-complex SVT.
- Give as a rapid IV bolus through a large proximal vein followed by flush.
- Sequence: 6 mg, then 12 mg, then 12 mg if needed.
- May be considered in selected regular monomorphic broad-complex tachycardia if SVT with aberrancy is likely and senior oversight is present.
- Do not use in irregular broad-complex tachycardia or pre-excited AF.
- If uncertain whether broad-complex tachycardia is VT, treat as VT and seek senior help.
- Transient flushing, chest tightness and dyspnoea are expected.
Noradrenaline
- First-line vasopressor in many forms of distributive shock, especially septic shock after fluid resuscitation where appropriate.
- Usually given as a titrated infusion with continuous monitoring.
- Central access is preferred, but short-term peripheral vasopressor use may be acceptable under local policy with close observation.
- Exam point: this is an ICU-level drug that may be started in ED, but it is not a routine bolus treatment for hypotension.
2. Hyperkalaemia and metabolic emergency drugs
| Drug | Main indication | Typical adult dose | Key exam point |
|---|---|---|---|
| Calcium chloride | Hyperkalaemia with ECG changes; CCB overdose | 10 mL of 10% IV | Stabilises myocardium; does not lower potassium |
| Calcium gluconate | Hyperkalaemia with ECG changes | 30 mL of 10% IV in many UK protocols | Peripheral option; repeat if ECG changes persist |
| Insulin with dextrose | Hyperkalaemia | Local protocol, commonly soluble insulin 10 units IV with glucose | Shifts potassium intracellularly; monitor for hypoglycaemia |
| Salbutamol | Asthma; adjunct in hyperkalaemia | Nebulised 5 mg, repeated as needed | Adjunct only in hyperkalaemia |
| Sodium bicarbonate | TCA toxicity; selected severe hyperkalaemia with acidosis | Depends on indication and local protocol | Not routine in prolonged arrest |
Calcium chloride and calcium gluconate
- Indication: hyperkalaemia with ECG changes.
- Common UK options:
- 10 mL of 10% calcium chloride IV, ideally via secure or central access
- 30 mL of 10% calcium gluconate IV, often preferred peripherally
- Repeat if ECG changes persist.
- Calcium stabilises the myocardium. It does not reduce serum potassium.
- Then give potassium-shifting therapy and address elimination.
- Local protocols vary slightly; know the principle and your formulary.
Insulin with dextrose
- Used after membrane stabilisation in significant hyperkalaemia.
- Common adult regimen: soluble insulin 10 units IV with glucose according to local protocol.
- Check glucose before treatment and monitor for several hours afterwards.
- Exam trap: insulin lowers potassium by shifting it intracellularly; it does not remove total body potassium.
Salbutamol
- Asthma/COPD exacerbation: nebulised 5 mg, repeated as needed.
- Hyperkalaemia: high-dose nebulised salbutamol may be used as adjunctive potassium-shifting therapy.
- Not a substitute for calcium in hyperkalaemia with ECG changes.
Sodium bicarbonate
- Not part of routine ALS and not a generic prolonged-arrest drug.
- High-yield indication: TCA overdose with QRS widening, ventricular arrhythmia, hypotension or seizures.
- Also considered in selected severe hyperkalaemia with significant metabolic acidosis.
- In TCA toxicity, the aim is sodium loading and alkalinisation; use toxicology guidance and local protocol.
- Exam trap: if the stem says overdose, hypotension, seizures and broad QRS after amitriptyline, think sodium bicarbonate.
3. Acute coronary syndrome, STEMI and acute cardiology drugs
| Drug | Main indication | Typical adult dose | Key exam point |
|---|---|---|---|
| Aspirin | ACS | 300 mg PO | Give early unless true contraindication |
| Ticagrelor | ACS, often PCI pathway dependent | 180 mg PO loading | Common DAPT partner with aspirin |
| Clopidogrel | Alternative antiplatelet in some ACS/stroke pathways | Usually 300-600 mg PO loading depending on pathway | Know local and cardiology pathway variation |
| Heparin | ACS/VTE/specialist pathways | Protocol dependent | Pathway-led, not a universal ED default |
| Glyceryl trinitrate | Ischaemic chest pain; acute pulmonary oedema with hypertension | SL spray/tablet or IV infusion | Avoid in hypotension and RV infarction |
| Tenecteplase | Thrombolysis in selected STEMI or other specialist indications | Weight-based IV bolus | Use depends on local PCI access and specialist pathway |
| Furosemide | Acute pulmonary oedema with fluid overload | Often 40-80 mg IV, tailored to patient | Not first treatment for all breathless heart failure patients |
Aspirin
- ACS: 300 mg orally as soon as possible unless contraindicated.
- Check for true allergy or active major bleeding.
- Exam trap: aspirin is standard in suspected ACS even before troponin result.
Ticagrelor and clopidogrel
- Used as part of dual antiplatelet therapy according to ACS pathway.
- Ticagrelor loading dose is commonly 180 mg orally.
- Clopidogrel loading varies by indication and pathway.
- For exams, know that antiplatelet choice is often pathway-led and may differ in STEMI, NSTEMI, stroke/TIA and after PCI.
Heparin
- Used in ACS, VTE and some specialist pathways.
- Unfractionated heparin or LMWH choice depends on indication and local protocol.
- Do not assume all chest pain gets heparin in ED.
Glyceryl trinitrate
- Useful for ischaemic chest pain and acute pulmonary oedema, especially if hypertensive.
- Routes: sublingual or IV infusion.
- Avoid or use extreme caution in hypotension, severe aortic stenosis, recent phosphodiesterase-5 inhibitor use and suspected right ventricular infarction.
Tenecteplase
- Used for thrombolysis in selected STEMI pathways where PCI is not available within target time, and in some other specialist indications.
- Weight-based IV bolus.
- Major contraindications include active bleeding, previous intracranial haemorrhage and many recent major surgery or stroke scenarios.
- Exam point: in the UK, primary PCI is preferred where available; thrombolysis is pathway-dependent.
Furosemide
- Useful in acute pulmonary oedema when fluid overload is present.
- Typical IV dose often 40-80 mg, adjusted for prior use and renal function.
- Nitrates and ventilatory support may be more immediately important than diuretics in hypertensive pulmonary oedema.
- Exam trap: not every breathless heart failure patient needs immediate furosemide.
4. Sedation, agitation, analgesia and antiemetic drugs
| Drug | Main indication | Typical adult dose | Key exam point |
|---|---|---|---|
| Ketamine | Procedural sedation; analgesia | 1-1.5 mg/kg IV or 4 mg/kg IM for dissociation | Excellent exam drug; know emergence and laryngospasm risks |
| Propofol | Procedural sedation | Titrated IV aliquots | Causes hypotension and apnoea; needs expertise |
| Midazolam | Sedation; seizures if buccal/IM/IV depending context | Context dependent | Useful when no IV access in seizures |
| Fentanyl | Severe pain; procedural analgesia | Titrated IV doses | Rapid onset, less histamine release than morphine |
| Morphine | Severe pain | Titrated IV doses | Watch hypotension and respiratory depression |
| Paracetamol | Mild-moderate pain; adjunct | 1 g PO/IV if appropriate | Simple but high-yield; check weight and liver disease |
| Ibuprofen | Pain, fever | 400 mg PO commonly | Avoid in GI bleed, AKI risk, some asthma patients |
| Ondansetron | Nausea/vomiting | 4 mg IV/PO | QT prolongation caution |
| Metoclopramide | Nausea/vomiting, migraine | 10 mg IV/IM/PO | Can cause dystonia and akathisia |
| Haloperidol | Agitation, delirium, antiemetic in selected settings | Low-dose titrated use | QT prolongation and extrapyramidal effects |
| Droperidol | Agitation, antiemetic, sedation pathways | Protocol dependent | Use varies by formulary and local policy |
Ketamine
- High-yield procedural sedation drug in ED.
- Dissociative sedation: commonly 1-1.5 mg/kg IV or 4 mg/kg IM.
- Provides analgesia and amnesia.
- Useful in haemodynamically fragile patients compared with some alternatives, but not risk-free.
- Adverse effects: emergence reaction, vomiting, hypersalivation, laryngospasm, transient hypertension and tachycardia.
- Requires full sedation governance: consent where possible, fasting considerations, monitoring, capnography, airway equipment and recovery observation.
Propofol
- Effective sedative for short procedures in experienced hands.
- Rapid onset and offset.
- Major risks: hypotension, apnoea and loss of airway reflexes.
- Exam point: excellent drug, but only with appropriate expertise, monitoring and airway readiness.
Midazolam
- Used for sedation and seizure control.
- In seizures, buccal or IM midazolam is useful when IV access is not available.
- Can cause respiratory depression, especially with opioids or alcohol.
Fentanyl and morphine
- Both are titratable opioid analgesics.
- Fentanyl has rapid onset and is often favoured for procedural analgesia.
- Morphine remains common for severe pain.
- Monitor respiratory rate, sedation level and blood pressure.
- Consider smaller doses in older adults and frail patients.
Paracetamol and ibuprofen
- Frequently overlooked in revision because they are common, but they appear in exam stems on multimodal analgesia and paediatrics.
- Paracetamol: check weight, liver disease and cumulative dose.
- Ibuprofen: avoid in significant renal impairment, GI bleeding risk and selected asthma patients with NSAID sensitivity.
Ondansetron and metoclopramide
- Ondansetron is useful and generally well tolerated but may prolong QT.
- Metoclopramide is useful in migraine and nausea but can cause dystonia and akathisia.
- Exam trap: acute dystonic reaction after metoclopramide or antipsychotic use.
Haloperidol and droperidol
- Used in selected agitation, delirium or antiemetic pathways.
- Both require caution with QT prolongation, extrapyramidal effects and underlying Parkinsonism or Lewy body disease.
- Use is protocol-dependent and should not replace treatment of reversible causes of agitation such as hypoxia, hypoglycaemia or head injury.
5. Seizure and status epilepticus drugs
| Drug | Main indication | Typical adult dose | Key exam point |
|---|---|---|---|
| Lorazepam | First-line IV benzodiazepine in status epilepticus | 4 mg IV, may repeat once | Move promptly to second-line if ongoing seizure |
| Diazepam | Alternative benzodiazepine | 10 mg IV or rectal depending context | Useful if lorazepam unavailable |
| Midazolam | Buccal/IM option when no IV access | 10 mg buccal/IM in adults commonly | High-yield no-IV-access answer |
| Levetiracetam | Second-line status epilepticus | 60 mg/kg IV, max 4.5 g | Common modern second-line choice |
| Phenytoin or fosphenytoin | Second-line status epilepticus | Phenytoin 20 mg/kg IV | Infusion complications and monitoring matter |
| Valproate | Second-line status epilepticus | 40 mg/kg IV, max 3 g | Avoid in pregnancy where possible |
Lorazepam, diazepam and midazolam
- First-line treatment in convulsive status epilepticus is a benzodiazepine.
- Lorazepam: 4 mg IV, may repeat once after about 10 minutes if seizure continues.
- Diazepam: common alternative, often 10 mg IV or rectal depending context.
- Midazolam: useful buccal or IM option when IV access is not available.
- Check glucose early and correct hypoglycaemia.
- Exam trap: do not keep repeating benzodiazepines indefinitely; escalate to second-line therapy.
Levetiracetam
- Common second-line agent in status epilepticus.
- Typical adult loading: 60 mg/kg IV up to 4.5 g.
- Generally easier to use than phenytoin and with fewer infusion-related cardiovascular issues.
Phenytoin or fosphenytoin
- Phenytoin remains examinable and clinically relevant.
- Typical loading: 20 mg/kg IV.
- Requires careful infusion and cardiac monitoring due to hypotension and arrhythmia risk.
- Fosphenytoin may be used where available and is often better tolerated.
- Exam trap: know the toxicity and infusion issues.
Valproate
- Another accepted second-line option in status epilepticus.
- Typical loading: 40 mg/kg IV up to 3 g.
- Avoid or use specialist advice in pregnancy and significant liver disease.
6. Anaphylaxis, asthma and airway-related drugs
| Drug | Main indication | Typical adult dose | Key exam point |
|---|---|---|---|
| Adrenaline | Anaphylaxis | 500 micrograms IM, repeat after 5 min if needed | First-line treatment |
| Salbutamol | Bronchospasm | 5 mg nebulised | Adjunct in anaphylaxis, not substitute for adrenaline |
| Ipratropium | Severe asthma/COPD | 500 micrograms nebulised | Adjunct bronchodilator |
| Hydrocortisone | Anaphylaxis adjunct; adrenal crisis; asthma/COPD pathways | 200 mg IV in many adult emergency settings | Not first-line in anaphylaxis |
| Dexamethasone | Croup; some airway/inflammatory indications | Context dependent | Know croup association |
| Magnesium sulphate | Severe/life-threatening asthma | 2 g IV | Adjunct in severe asthma |
Salbutamol and ipratropium
- Salbutamol: nebulised 5 mg in adults, repeated as needed.
- Ipratropium: 500 micrograms nebulised, especially in severe asthma or COPD exacerbation.
- In anaphylaxis with wheeze, salbutamol is an adjunct. Adrenaline remains first-line.
Hydrocortisone and dexamethasone
- Hydrocortisone is no longer the immediate life-saving treatment in anaphylaxis; adrenaline is.
- Hydrocortisone may still appear in adjunctive treatment or in adrenal crisis.
- Dexamethasone is high-yield in croup and some inflammatory airway conditions.
- Exam trap: if the stem is true anaphylaxis, the answer is IM adrenaline, not steroid or antihistamine.
7. Sepsis, meningitis and CNS infection drugs
| Drug | Main indication | Typical adult dose | Key exam point |
|---|---|---|---|
| Ceftriaxone | Meningitis, sepsis pathways | 2 g IV in many adult meningitis regimens | Classic exam antibiotic |
| Piperacillin-tazobactam | Broad-spectrum sepsis cover | 4.5 g IV commonly | Check local antimicrobial policy |
| Gentamicin | Gram-negative cover in selected sepsis pathways | Weight-based IV | Renal dosing and toxicity matter |
| Vancomycin | MRSA or resistant Gram-positive cover | Weight-based IV | Protocol and level monitoring dependent |
| Aciclovir | Suspected encephalitis | 10 mg/kg IV usually | Think encephalitis, not meningitis alone |
Ceftriaxone
- High-yield for suspected bacterial meningitis and some severe sepsis pathways.
- Adult meningitis regimens commonly use 2 g IV.
- Give promptly when meningitis is suspected; do not delay for imaging unless clearly required.
Piperacillin-tazobactam, gentamicin and vancomycin
- These are important ED antibiotics but highly policy-dependent.
- Piperacillin-tazobactam is common broad-spectrum sepsis cover.
- Gentamicin is weight-based and nephrotoxic/ototoxic; check renal function and local dosing.
- Vancomycin is used for resistant Gram-positive cover and requires protocol-based dosing and monitoring.
- Exam point: know that local antimicrobial policy matters.
Aciclovir
- Think encephalitis: fever, altered mental state, focal neurology, seizure, temporal lobe features.
- Typical adult dose: 10 mg/kg IV, adjusted for renal function.
- Do not miss this in suspected HSV encephalitis.
8. Toxicology and antidote drugs
| Drug | Main indication | Typical adult dose | Key exam point |
|---|---|---|---|
| Naloxone | Opioid toxicity | Titrated IV/IM/IN | Reverse respiratory depression, not necessarily full consciousness |
| Flumazenil | Selected benzodiazepine reversal | Titrated IV | Often contraindicated in overdose |
| Digoxin-specific antibody fragments | Life-threatening digoxin toxicity | Specialist/toxicology guided | Think arrhythmia, hyperkalaemia, severe toxicity |
| Activated charcoal | Selected recent overdose | 50 g PO/NG commonly | Time window and airway safety matter |
| N-acetylcysteine | Paracetamol overdose | IV regimen per current UK protocol | Know nomogram logic and staggered overdose principles |
| Glucagon | Hypoglycaemia without IV access; selected beta-blocker toxicity | Context dependent | Not first-line if IV dextrose available in hypoglycaemia |
| Sodium bicarbonate | TCA toxicity | Protocol guided | Classic antidotal emergency use |
Naloxone
- Use in opioid-induced respiratory depression.
- Titrate to adequate ventilation rather than full wakefulness, especially in opioid-dependent patients.
- Routes include IV, IM and intranasal depending context.
- Exam trap: over-reversal can precipitate acute withdrawal, agitation and vomiting.
Flumazenil
- Rarely used in undifferentiated overdose.
- May precipitate seizures in mixed overdose, TCA co-ingestion or benzodiazepine dependence.
- Usually reserved for very selected cases after expert advice.
- Exam trap: in overdose, flumazenil is often the wrong answer.
Digoxin-specific antibody fragments
- Indicated in life-threatening digoxin toxicity, for example severe arrhythmia, significant hyperkalaemia or haemodynamic instability.
- Use specialist or toxicology advice.
- Exam clue: elderly patient on digoxin with visual symptoms, bradyarrhythmia and hyperkalaemia.
Activated charcoal
- Useful only in selected poisonings, usually within about 1 hour of ingestion, though longer for some modified-release or delayed-absorption drugs.
- Do not give if airway is unprotected or aspiration risk is high unless airway secured.
- Exam trap: charcoal is not a universal overdose treatment.
N-acetylcysteine
- Antidote for paracetamol overdose.
- Use current UK regimen and nomogram-based or risk-based indications.
- Staggered overdose, uncertain timing or delayed presentation often trigger treatment even without a nomogram point.
- Exam point: know that UK management is protocol-driven and time-sensitive.
Glucagon
- Can be used for hypoglycaemia when IV access is not available.
- Also has a role in selected beta-blocker overdose.
- Less effective in malnourished or glycogen-depleted patients.
9. Major haemorrhage and trauma drug
| Drug | Main indication | Typical adult dose | Key exam point |
|---|---|---|---|
| Tranexamic acid | Major trauma bleeding; major haemorrhage; postpartum haemorrhage pathways | 1 g IV then further dosing per protocol | Give early in significant bleeding |
Tranexamic acid
- Antifibrinolytic used in major haemorrhage.
- In trauma, early administration is important.
- Common adult regimen begins with 1 g IV, followed by protocol-based further dosing.
- Exam trap: TXA is adjunctive to haemorrhage control and blood product resuscitation, not a substitute.
10. The full top 50 quick-reference list
| Drug | Typical ED indication | One-line exam trigger |
|---|---|---|
| Adrenaline | Arrest, anaphylaxis | Know route and concentration by scenario |
| Noradrenaline | Shock | Titrated vasopressor infusion |
| Amiodarone | Refractory VF/pVT | After 3rd shock |
| Lidocaine | Alternative antiarrhythmic in VF/pVT | Alternative to amiodarone |
| Magnesium sulphate | Torsades, severe asthma, eclampsia | Think torsades |
| Atropine | Symptomatic bradycardia | 500 micrograms IV |
| Adenosine | Stable regular narrow-complex SVT | Avoid in irregular broad-complex |
| Calcium chloride | Hyperkalaemia with ECG changes | Membrane stabilisation |
| Calcium gluconate | Hyperkalaemia with ECG changes | Peripheral option |
| Sodium bicarbonate | TCA toxicity | Broad QRS overdose |
| Aspirin | ACS | 300 mg PO |
| Glyceryl trinitrate | ACS, pulmonary oedema | Avoid in hypotension/RV infarct |
| Clopidogrel | ACS/pathway-led antiplatelet use | Know pathway variation |
| Ticagrelor | ACS | Common DAPT loading drug |
| Heparin | ACS/VTE | Protocol dependent |
| Tenecteplase | Selected thrombolysis | PCI pathway dependent |
| Furosemide | Pulmonary oedema | Not first answer in all cases |
| Ketamine | Procedural sedation | Dissociative sedation |
| Propofol | Procedural sedation | Hypotension/apnoea risk |
| Midazolam | Sedation, seizures | No-IV-access seizure option |
| Lorazepam | Status epilepticus | IV first-line benzodiazepine |
| Diazepam | Status epilepticus | Alternative benzodiazepine |
| Fentanyl | Severe pain | Rapid titratable opioid |
| Morphine | Severe pain | Monitor for respiratory depression |
| Paracetamol | Pain, fever | Simple but examinable |
| Ibuprofen | Pain, fever | NSAID cautions |
| Ondansetron | Nausea/vomiting | QT caution |
| Metoclopramide | Nausea/migraine | Dystonia risk |
| Haloperidol | Agitation/delirium pathways | QT and EPS caution |
| Droperidol | Agitation/antiemetic pathways | Local policy dependent |
| Salbutamol | Asthma, hyperkalaemia adjunct | Adjunct in hyperkalaemia |
| Ipratropium | Severe asthma/COPD | Adjunct bronchodilator |
| Hydrocortisone | Adrenal crisis, asthma/COPD, anaphylaxis adjunct | Not first-line in anaphylaxis |
| Dexamethasone | Croup and inflammatory indications | Think croup |
| Ceftriaxone | Meningitis/sepsis | Classic exam antibiotic |
| Piperacillin-tazobactam | Broad-spectrum sepsis cover | Local policy matters |
| Gentamicin | Gram-negative sepsis cover | Weight and renal function matter |
| Vancomycin | Resistant Gram-positive infection | Protocol and monitoring dependent |
| Aciclovir | Encephalitis | Do not miss HSV encephalitis |
| Naloxone | Opioid toxicity | Titrate to ventilation |
| Flumazenil | Selected benzodiazepine reversal | Usually avoid in overdose |
| Digoxin-specific antibody fragments | Severe digoxin toxicity | Think arrhythmia plus hyperkalaemia |
| Activated charcoal | Selected overdose | Timing and airway matter |
| N-acetylcysteine | Paracetamol overdose | Protocol-driven antidote |
| Insulin with dextrose | Hyperkalaemia | Shifts potassium intracellularly |
| Glucagon | Hypoglycaemia without IV access; beta-blocker toxicity | Context dependent |
| Levetiracetam | Status epilepticus second-line | Common modern choice |
| Phenytoin or fosphenytoin | Status epilepticus second-line | Infusion monitoring matters |
| Valproate | Status epilepticus second-line | Avoid in pregnancy where possible |
| Tranexamic acid | Major haemorrhage | Give early |
Immediate priorities in ED management:
- treat immediately reversible threats first: defibrillation, airway manoeuvres, oxygen when indicated, glucose correction, haemorrhage control
- give time-critical drugs early: IM adrenaline in anaphylaxis, benzodiazepine in status epilepticus, calcium in hyperkalaemia with ECG changes, aspirin in ACS, antibiotics in sepsis, NAC in indicated paracetamol overdose, TXA in major haemorrhage
- reassess after each intervention
- escalate promptly if first-line treatment fails
Later care includes:
- infusions and ongoing titration
- repeat ECGs and blood tests
- toxicology consultation
- critical care referral
- definitive imaging or intervention
- observation for recurrence or delayed toxicity
Disposition, Referral and Follow-Up
- Cardiac arrest survivors, unstable arrhythmias, vasopressor-dependent shock, severe hyperkalaemia, refractory seizures and significant overdose usually require HDU/ICU-level care.
- ACS patients require cardiology pathway management and telemetry where indicated.
- Meningitis, encephalitis and severe sepsis require urgent senior review and specialty input.
- Procedural sedation patients need formal recovery criteria before discharge.
- Opioid overdose reversed with naloxone requires observation because naloxone may wear off before the opioid.
- Paracetamol overdose requires protocol-based follow-up bloods and mental health assessment where appropriate.
- Major haemorrhage requires definitive haemostasis pathway and often theatre, IR or obstetric involvement.
Special Groups
Paediatrics
- Weight-based dosing is critical.
- Adrenaline in paediatric anaphylaxis is age/weight based, not the fixed adult 500 microgram dose.
- Status epilepticus treatment differs by weight and route.
- Paracetamol and ibuprofen dosing errors are common exam themes.
- Croup and dexamethasone are especially high yield in paediatric EM.
Pregnancy
- Do not withhold life-saving treatment because of pregnancy.
- Adrenaline remains first-line in anaphylaxis.
- Magnesium sulphate is central in eclampsia.
- Valproate should generally be avoided where possible.
- Consider fetal implications, but maternal resuscitation takes priority.
Older adults and frailty
- Use lower initial doses for sedatives and opioids.
- Renal impairment affects gentamicin, vancomycin, aciclovir and many others.
- Digoxin toxicity is more common.
- Delirium may worsen with antipsychotics and sedatives.
Immunosuppressed patients
- Broader antimicrobial cover may be needed.
- Lower threshold for aciclovir in suspected encephalitis.
- Atypical presentations are common.
Common Pitfalls
- Confusing adrenaline 1:1000 IM for anaphylaxis with 1:10,000 IV/IO for arrest.
- Giving adrenaline before the third shock in VF/pVT.
- Using adenosine in irregular broad-complex tachycardia.
- Assuming calcium lowers potassium.
- Forgetting to repeat calcium if ECG changes persist.
- Repeating benzodiazepines too many times instead of moving to second-line status treatment.
- Using flumazenil in mixed overdose or benzodiazepine dependence.
- Over-reversing opioid-dependent patients with naloxone.
- Choosing hydrocortisone or chlorphenamine instead of IM adrenaline in anaphylaxis.
- Giving furosemide as the first answer in all acute heart failure questions.
- Ignoring local policy for antibiotics, thrombolysis and agitation management.
- Using propofol or ketamine without sedation governance, capnography and airway backup.
FRCEM and MRCEM Exam Tips
- Learn drugs by scenario, not alphabetically.
- For every drug, know five facts: indication, route, adult dose, repeat logic, one major caution.
- Always ask: why this drug, why this route, why now, and what makes it unsafe?
- In SBAs, rhythm recognition often matters more than drug recall.
- In OSCEs, verbalise monitoring, contraindications and escalation.
- If a patient is unstable, electrical or procedural treatment may come before the drug.
- Know the classic pairs:
- adrenaline arrest versus anaphylaxis
- amiodarone versus lidocaine
- calcium chloride versus calcium gluconate
- lorazepam versus midazolam when no IV access
- naloxone versus flumazenil
How This Appears in SBA Questions
Typical question stems:
- “A 64-year-old man remains in VF after three shocks. Which drug should be given now?”
- “A 23-year-old woman with urticaria, wheeze and hypotension after peanuts. What is the first-line drug, dose and route?”
- “A stable patient has a regular narrow-complex tachycardia at 190 bpm despite vagal manoeuvres. What next?”
- “A patient with potassium 7.2 mmol/L has peaked T waves and broad QRS. Which drug should be given first?”
- “A convulsing patient has no IV access. What is the most appropriate first-line drug?”
- “A drowsy patient has RR 6/min and pinpoint pupils after heroin use. What is the immediate antidote strategy?”
- “An overdose patient has hypotension, seizures and a broad QRS after amitriptyline. Which treatment is indicated?”
- “A patient with suspected HSV encephalitis is febrile, confused and fitting. Which antiviral should be started?”
Key discriminator clues:
- “after the third shock” points to adrenaline and amiodarone sequence in shockable arrest
- “IM” and “anterolateral thigh” point to anaphylaxis adrenaline
- “regular narrow-complex” points to adenosine after vagal manoeuvres
- “irregular broad-complex” makes adenosine unsafe
- “ECG changes in hyperkalaemia” means calcium first
- “no IV access in status epilepticus” points to buccal/IM midazolam
- “opioid-dependent” means titrated naloxone, not full reversal
- “TCA overdose with broad QRS” points to sodium bicarbonate
Common wrong-answer traps:
- hydrocortisone instead of adrenaline in anaphylaxis
- amiodarone in asystole
- adenosine in AF with WPW
- insulin before calcium in unstable hyperkalaemia with ECG changes
- flumazenil in mixed overdose
- furosemide before nitrates/CPAP in hypertensive pulmonary oedema
Key Takeaways
- Emergency drug questions are usually questions about context, sequence and safety.
- Adrenaline is the highest-yield drug: know arrest versus anaphylaxis differences perfectly.
- Amiodarone is for refractory shockable arrest, not all arrests.
- Adenosine is for stable regular narrow-complex SVT; avoid it in irregular broad-complex tachycardia.
- In hyperkalaemia with ECG changes, calcium comes first and stabilises the myocardium only.
- Status epilepticus requires prompt escalation from benzodiazepines to second-line therapy.
- Naloxone should be titrated to ventilation; flumazenil is often unsafe in overdose.
- Ketamine, propofol and agitation drugs require full sedation governance and monitoring.
- Antibiotic and thrombolysis choices are often pathway-dependent; know national principles and local policy.
- For OSCEs, always mention monitoring, reassessment and escalation.
Further Reading
- Resuscitation Council UK adult advanced life support guidance
- Resuscitation Council UK anaphylaxis guidance
- RCEM guidance on procedural sedation and emergency care pathways
- NICE guidance on acute coronary syndromes
- NICE guidance on epilepsies and status epilepticus-related care
- BTS/SIGN British guideline on the management of asthma
- TOXBASE for UK toxicology management
- NICE antimicrobial prescribing guidance and local trust antimicrobial policy
- Joint Royal Colleges Ambulance Liaison Committee and NHS major haemorrhage pathways where relevant
Related on EM Final Exams
- RSI Drugs Explained for FRCEM Exams
- Sedation in ED Exam Essentials
- Inotropes and Vasopressors for FRCEM
- Top Toxicology Presentations in SBA Exams
Authoritative Sources
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