Here is a comprehensive intern-level reference guide for emergency drugs across all five major conditions. All dosing sourced from Rosen's Emergency Medicine, Tintinalli's Emergency Medicine, Adams and Victor's Neurology, Comprehensive Clinical Nephrology (7th ed.), Katzung's Pharmacology (16th ed.), and Goodman & Gilman's.
Emergency Drugs: A Practical Guide for Interns and Junior Residents
CONDITION 1: CARDIAC ARREST (ACLS)
Immediate priorities: CPR quality + early defibrillation + IV/IO access
1. EPINEPHRINE (Adrenaline)
| Feature | Details |
|---|
| Indication | VF/pVT (after 2nd shock), pulseless PEA, asystole |
| Mechanism | Non-selective alpha + beta agonist. Alpha-1 vasoconstriction increases coronary perfusion pressure during CPR. Beta-1 increases myocardial contractility and heart rate |
| Contraindication | No absolute CI in cardiac arrest. Relative: cocaine-induced arrest (may worsen coronary spasm) |
| Dose | 1 mg IV/IO every 3-5 minutes |
| Dilution & Route | Give undiluted as 1 mg/10 mL (1:10,000) IV push, followed by 20 mL NS flush. Flush arm and elevate limb if using peripheral IV to ensure delivery to central circulation |
| Timing | In VF/pVT: give epinephrine after the 2nd unsuccessful shock. In non-shockable rhythms (PEA/asystole): give as soon as IV/IO access established |
| Key pearl | High-dose epinephrine (>1 mg) does NOT improve survival and may worsen post-resuscitation myocardial dysfunction |
2. AMIODARONE
| Feature | Details |
|---|
| Indication | Shock-refractory VF or pulseless VT (after 3+ shocks) |
| Mechanism | Class III antiarrhythmic - blocks K+ channels (prolongs repolarization), also has Class I (Na+ block), II (beta-block), and IV (Ca2+ block) properties |
| Contraindications | Iodine allergy, thyroid disorders, cardiogenic shock with hemodynamic compromise (relative), torsades de pointes, hypersensitivity |
| Dose | First dose: 300 mg IV/IO bolus. Second dose (if needed): 150 mg IV/IO |
| Dilution | Dilute in 20-30 mL D5W (NOT NS - precipitates). Give as rapid IV push during CPR |
| Key pearl | Use amiodarone OR lidocaine, not both. Amiodarone preferred if no prior lidocaine |
3. LIDOCAINE
| Feature | Details |
|---|
| Indication | Alternative to amiodarone in refractory VF/pVT |
| Mechanism | Class Ib antiarrhythmic - blocks fast sodium channels, suppressing ventricular ectopy |
| Contraindications | Stokes-Adams syndrome, severe SA/AV/intraventricular block (without pacemaker), allergy to amide LAs, hypotension |
| Dose | 1-1.5 mg/kg IV/IO bolus; repeat at 0.5-0.75 mg/kg every 5-10 min (max 3 mg/kg total) |
| Dilution | Give undiluted 2% solution IV push |
| Post-ROSC infusion | If lidocaine terminated VF, start maintenance infusion at 1-4 mg/min |
4. ATROPINE
| Feature | Details |
|---|
| Indication | Symptomatic bradycardia (hypotension, altered consciousness, signs of shock). NOT recommended for asystole or PEA |
| Mechanism | Competitive muscarinic (M2) antagonist - blocks vagal tone, increases SA node automaticity and AV conduction |
| Contraindications | Narrow-angle glaucoma, tachyarrhythmias, myasthenia gravis (relative), ileus. Do NOT rely on atropine in high-degree (Mobitz II or 3rd degree) AV block - use pacing |
| Dose | 0.5 mg IV every 3-5 minutes (max 3 mg total). Doses < 0.5 mg may paradoxically worsen bradycardia (central vagal stimulation) |
| Dilution | Give undiluted IV push |
| Alternative | If no IV access: 1 mg ET tube (dilute in 10 mL NS). ET route is least reliable - use only if no IV/IO available |
5. VASOPRESSIN
| Feature | Details |
|---|
| Indication | Alternative to 1st or 2nd dose of epinephrine in cardiac arrest |
| Mechanism | V1 receptor agonist - vasoconstriction via smooth muscle V1 receptors, independent of adrenergic receptors; useful when catecholamines fail |
| Dose | 40 units IV/IO once (replaces 1st or 2nd dose of epinephrine) |
| Current status | 2015 AHA guidelines removed vasopressin as a separate recommendation (no added benefit over epi). Some centers still use it |
6. SODIUM BICARBONATE
| Feature | Details |
|---|
| Indication | Hyperkalemia-induced arrest, TCA overdose, prolonged arrest with documented severe metabolic acidosis (pH <7.1), cocaine toxicity |
| Mechanism | Buffers H+ ions, raises blood pH; in TCA overdose alkalinization narrows QRS and reverses sodium channel blockade |
| Contraindications | Routine use in cardiac arrest is NOT recommended (can worsen intracellular acidosis, impair oxygen delivery, cause hypernatremia) |
| Dose | 1 mEq/kg IV bolus; reassess with ABG |
| Dilution | 8.4% solution (1 mEq/mL). Use dedicated line - incompatible with calcium salts |
7. CALCIUM CHLORIDE / CALCIUM GLUCONATE
| Feature | Details |
|---|
| Indication | Hyperkalemia arrest, hypocalcemia, calcium channel blocker overdose |
| Mechanism | Stabilizes cardiac membrane potential, counteracts effects of hyperkalemia on the myocardium |
| Dose | Calcium chloride 10%: 5-10 mL (500-1000 mg) IV. Calcium gluconate 10%: 15-30 mL (three times less elemental Ca than CaCl) |
| Route | Central line preferred for CaCl (causes severe tissue necrosis if extravasated). Gluconate is safer peripherally |
| Key pearl | Do NOT give in digoxin toxicity (hypercalcemia worsens digoxin toxicity - "stone heart" effect) |
CONDITION 2: ANAPHYLAXIS
First-line: Epinephrine IM - do not delay for antihistamines
1. EPINEPHRINE (FIRST AND ONLY MANDATORY DRUG)
| Feature | Details |
|---|
| Indication | All cases of anaphylaxis (not "maybe anaphylaxis" - if anaphylaxis is your diagnosis, give it now) |
| Mechanism | Alpha-1: vasoconstriction (reverses hypotension + angioedema). Beta-1: positive inotropy/chronotropy. Beta-2: bronchodilation + mast cell mediator release inhibition |
| Contraindications | No absolute CI in anaphylaxis. Relative (only in non-life-threatening reactions): ischaemic heart disease, hypertension, hyperthyroidism, cocaine use |
| Dose | 0.3-0.5 mg IM (adult). Child: 0.01 mg/kg IM (max 0.5 mg) |
| Dilution & Route | Use 1:1,000 solution (1 mg/mL). Inject IM into the outer mid-thigh (vastus lateralis) - faster peak serum levels than deltoid. Do NOT give 1:1,000 IV (causes hypertensive crisis/VF). Repeat every 5-15 min if no response |
| IV route | Only in cardiac arrest-like anaphylaxis: dilute to 1:10,000 (0.1 mg/mL), give 0.1 mg IV slowly titrated. Or IV infusion 1-4 mcg/min |
| Key pearl | Antihistamines and steroids do NOT treat the acute life-threatening features. Epinephrine is the only drug that does |
2. DIPHENHYDRAMINE (H1-blocker)
| Feature | Details |
|---|
| Indication | Adjunct - treats urticaria and pruritus AFTER epinephrine given |
| Mechanism | Competitive H1 receptor antagonist |
| Dose | 25-50 mg IV/IM/PO |
| Route | IV: give slowly over 1-2 min. IM: deltoid or thigh |
| Contraindications | Glaucoma, BPH, MAO inhibitor use |
3. RANITIDINE / FAMOTIDINE (H2-blocker)
| Feature | Details |
|---|
| Indication | Adjunct - combined H1+H2 blockade more effective for urticaria and hypotension than H1 alone |
| Dose | Ranitidine 50 mg IV over 5 min OR famotidine 20 mg IV |
4. HYDROCORTISONE / METHYLPREDNISOLONE
| Feature | Details |
|---|
| Indication | Adjunct - prevents biphasic anaphylaxis (delayed recurrence 4-12 hours later) |
| Mechanism | Inhibits phospholipase A2 (blocks arachidonic acid cascade), reduces late-phase mediator release, reduces vascular permeability |
| Dose | Hydrocortisone 200-500 mg IV OR methylprednisolone 1-2 mg/kg IV |
| Key pearl | Takes 4-6 hours to work - does NOT help the acute episode. Its role is preventing biphasic reactions |
5. SALBUTAMOL (ALBUTEROL) NEBULISATION
| Feature | Details |
|---|
| Indication | Bronchospasm in anaphylaxis not responding to epinephrine |
| Dose | 2.5-5 mg nebulised. Repeat as needed |
| Key pearl | Does NOT replace epinephrine. Treats bronchospasm only - does not reverse hypotension or angioedema |
CONDITION 3: HYPERTENSIVE EMERGENCY
Key principle: Goal is NOT rapid normalisation. Reduce MAP by no more than 25% in the first hour, then to ~160/100 over the next 2-6 hours. Abrupt normalisation risks cerebral, coronary, and renal ischaemia due to impaired autoregulation. - Comprehensive Clinical Nephrology, 7th Ed.
IV Drugs (use in ICU/HDU with continuous BP monitoring)
1. NICARDIPINE
| Feature | Details |
|---|
| Indication | Most hypertensive emergencies; preferred in AKI, hypertensive encephalopathy, post-op HTN, acute stroke |
| Mechanism | Dihydropyridine calcium channel blocker - arteriolar vasodilation, reduces SVR |
| Contraindications | Acute heart failure (causes reflex tachycardia and may worsen HF), severe aortic stenosis |
| Dose | Initial: 5 mg/h IV infusion. Increase by 2.5 mg/h every 5-15 min up to 15 mg/h |
| Onset / Duration | Onset 5-15 min; duration 15-30 min (may extend to 4 hours) |
| Dilution | Premixed bags available. If manual: 25 mg in 240 mL NS = 0.1 mg/mL. Use dedicated IV line |
| Adverse effects | Tachycardia, headache, flushing, nausea, phlebitis at injection site |
2. LABETALOL
| Feature | Details |
|---|
| Indication | Hypertensive emergency with tachycardia, aortic dissection, catecholamine excess (pheochromocytoma), pregnancy-related hypertension, hypertensive encephalopathy |
| Mechanism | Alpha-1 + nonselective beta blocker (beta:alpha ratio ~7:1 IV). Reduces HR, SVR, and BP without reflex tachycardia |
| Contraindications | Asthma/COPD, acute decompensated HF, bradycardia or heart block, cocaine toxicity (paradoxically worsens hypertension due to unopposed alpha effect) |
| Dose IV bolus | 10-20 mg IV over 2 min; repeat 20-80 mg every 10 min (max 300 mg total) |
| Dose IV infusion | 0.5-2 mg/min continuous infusion |
| Oral | 200-400 mg PO every 2-3 hours (for urgency, not emergency) |
| Onset / Duration | Onset: 5-10 min; duration 3-6 hours |
| Key pearl | Labetalol is the preferred drug in aortic dissection (alongside esmolol) and in pregnancy/eclampsia |
3. SODIUM NITROPRUSSIDE
| Feature | Details |
|---|
| Indication | Hypertensive emergency with acute pulmonary oedema, acute aortic dissection (with beta-blocker), or when rapid, titratable effect is needed |
| Mechanism | Direct arteriolar and venous vasodilator via NO release - reduces both preload and afterload |
| Contraindications | Compensatory hypertension (AV shunt, coarctation), acute ischaemic stroke (coronary steal), severe hepatic/renal failure (cyanide/thiocyanate accumulation), pregnancy |
| Dose | 0.25-0.5 mcg/kg/min IV; titrate up to 10 mcg/kg/min. Do not exceed 10 mcg/kg/min |
| Dilution | Dilute 50 mg in 250 mL D5W (200 mcg/mL). Wrap bag and tubing in foil - light sensitive. Use within 4 hours of preparation |
| Toxicity | Cyanide toxicity (especially > 3 mcg/kg/min for >72h or renal failure). Signs: metabolic acidosis, tachyphylaxis, mental status changes |
| Onset / Duration | Onset: immediate (seconds); duration: 1-2 min after stopping |
| Key pearl | Avoid in acute ischaemic stroke (causes intracerebral steal); avoid in aortic dissection as monotherapy |
4. ESMOLOL
| Feature | Details |
|---|
| Indication | Aortic dissection (FIRST line for rate control), perioperative HTN, HTN with tachycardia |
| Mechanism | Ultra-short-acting selective beta-1 blocker. Reduces HR and cardiac output, decreasing dp/dt (rate of pressure rise in the aorta) |
| Contraindications | Severe bradycardia, heart block, acute decompensated HF, asthma |
| Dose | Loading: 500 mcg/kg IV over 1 min; then infusion 50-300 mcg/kg/min |
| Onset / Duration | Onset 60 seconds; duration 10-20 min (ideal for fine titration) |
| Key pearl | In aortic dissection: give esmolol BEFORE a vasodilator (like nitroprusside) to prevent reflex tachycardia that increases aortic wall stress |
5. HYDRALAZINE
| Feature | Details |
|---|
| Indication | Hypertension in pregnancy / eclampsia (commonly used; well-studied in obstetric setting) |
| Mechanism | Direct arteriolar vasodilator via NO mechanism |
| Contraindications | Dissecting aortic aneurysm, coronary artery disease, SLE (causes drug-induced lupus with chronic use) |
| Dose | 5-10 mg IV slow bolus every 20 min (max 30 mg). Onset 10-20 min, duration 2-6 h |
| Key pearl | Unpredictable response; not preferred for most emergencies. Reserved mainly for pre-eclampsia/eclampsia |
6. GLYCERYL TRINITRATE (Nitroglycerin / GTN)
| Feature | Details |
|---|
| Indication | Hypertensive emergency WITH acute pulmonary oedema or ACS |
| Mechanism | Venous and (at high dose) arteriolar vasodilation via NO release. Predominantly reduces preload; reduces cardiac filling pressures |
| Contraindications | Hypotension (SBP <90), right ventricular infarction, severe aortic stenosis, PDE5 inhibitor use within 24-48 h (sildenafil/tadalafil) |
| Dose | IV infusion: start 5-10 mcg/min; titrate up to 200 mcg/min. SL: 0.4 mg tablet/spray every 5 min x 3 |
| Dilution | 50 mg in 250 mL D5W (200 mcg/mL). Use non-PVC tubing (NTG adsorbs to PVC) |
CONDITION 4: ACUTE SEVERE ASTHMA
Severity markers triggering "emergency" treatment: Unable to complete sentences, RR >25, HR >110, PEFR <50% predicted, SpO2 <92%, silent chest (life-threatening), cyanosis, exhaustion, altered consciousness.
1. SALBUTAMOL (ALBUTEROL) - BETA-2 AGONIST
| Feature | Details |
|---|
| Indication | First-line bronchodilator in acute asthma |
| Mechanism | Selective beta-2 agonist - activates adenylyl cyclase, raises cAMP, causes smooth muscle relaxation via PKA-mediated MLCK phosphorylation |
| Contraindications | Hypersensitivity. Use cautiously: tachyarrhythmias, hypokalaemia (beta-2 agonists shift K+ intracellularly) |
| Dose (nebulised) | 2.5-5 mg in 3 mL NS via nebuliser every 20 min for 3 doses, then 1-4 hourly. In life-threatening: continuous nebulisation 10-15 mg/hour |
| Dose (MDI + spacer) | 4-8 puffs every 20 min (equivalent to nebuliser in mild-moderate) |
| Dose (IV) | 250 mcg IV slow bolus; then 3-20 mcg/min infusion (when nebulised route fails) |
| Key pearl | Monitor K+ - continuous nebulisation causes hypokalaemia |
2. IPRATROPIUM BROMIDE (ATROVENT)
| Feature | Details |
|---|
| Indication | Added to salbutamol in severe/life-threatening asthma for first 24 h (combination superior to salbutamol alone) |
| Mechanism | Competitive muscarinic (M1/M3) antagonist - reduces vagally mediated bronchoconstriction and mucus secretion |
| Contraindications | Narrow-angle glaucoma (if aerosolised drug contacts eyes), urinary retention, hypersensitivity to atropine or its derivatives |
| Dose | 0.5 mg nebulised every 20 min for 3 doses, then every 4-6 h (given combined with salbutamol) |
3. SYSTEMIC CORTICOSTEROIDS
| Feature | Details |
|---|
| Indication | All acute severe asthma requiring emergency treatment. Give within 1 hour of presentation |
| Mechanism | Genomic: inhibits inflammatory cytokine gene transcription. Non-genomic: reduces vascular permeability, inhibits eosinophil survival, upregulates beta-2 receptor expression |
| Dose | Oral prednisolone 40-50 mg daily OR IV hydrocortisone 100 mg every 6 h (if cannot swallow) for 5 days |
| Onset | Clinical benefit within 4-6 hours |
| Key pearl | Oral prednisolone is as effective as IV hydrocortisone. Use IV only if vomiting or intubated |
4. MAGNESIUM SULPHATE (MgSO4)
| Feature | Details |
|---|
| Indication | Acute severe asthma not responding to initial bronchodilator treatment after 15-30 min; life-threatening asthma |
| Mechanism | Inhibits Ca2+-dependent smooth muscle contraction (blocks Ca2+ entry into smooth muscle), potentiates beta-2 agonist effect, reduces acetylcholine release from nerve terminals |
| Contraindications | Hypermagnesaemia, renal failure (relative - use with caution), myasthenia gravis |
| Dose | 2 g IV over 20 minutes as single dose (adult) |
| Dilution | 8 mmol (2 g) in 100 mL NS or D5W. Run over 20 min |
| Monitoring | Watch for loss of patellar reflex (first sign of toxicity), respiratory depression, hypotension. Antidote: calcium gluconate 10% 10 mL IV |
5. HELIOX (Helium-Oxygen mixture 70:30)
| Feature | Details |
|---|
| Indication | Severe refractory asthma pending intubation, reduces work of breathing |
| Mechanism | Helium is less dense than nitrogen - reduces turbulent airflow in narrow airways, decreasing work of breathing |
| Dose | 70% He / 30% O2 via non-rebreather mask. Note: FiO2 only 0.3, so avoid if severely hypoxic |
CONDITION 5: STATUS EPILEPTICUS
Definition: Continuous seizure activity >5 minutes OR two or more seizures without full recovery of consciousness between them.
Time-sensitive approach: Lorazepam at 0-5 min → phenytoin/levetiracetam at 20-40 min → anesthetic doses at 60 min
STEP 1 (0-5 MIN): BENZODIAZEPINES
A. LORAZEPAM (Preferred first-line)
| Feature | Details |
|---|
| Indication | First-line for status epilepticus; terminates ~60-70% of cases |
| Mechanism | Positive allosteric modulator at GABA-A receptor - increases Cl- influx frequency, hyperpolarising the neuron |
| Contraindications | Severe respiratory depression, hypersensitivity, acute narrow-angle glaucoma |
| Dose | 0.1 mg/kg IV over 1-2 min (max 4 mg per dose). Repeat after 5 min if still seizing (max 12 mg total in adults) |
| Advantage over diazepam | Less redistribution - longer duration of antiseizure effect (12-24 h vs 20-30 min for diazepam). Recent appraisals have questioned whether this pharmacokinetic advantage translates into clear clinical superiority - Katzung, 16th Ed. |
B. DIAZEPAM
| Feature | Details |
|---|
| Indication | Alternative first-line if lorazepam unavailable; preferred via rectal route when IV access impossible |
| Mechanism | Same as lorazepam (GABA-A potentiation) |
| Dose IV | 0.15-0.2 mg/kg IV over 1-2 min (max 10 mg per dose); repeat every 5 min to maximum of 30 mg |
| Dose rectal | 10-20 mg PR (useful in community setting and paediatrics) |
| Key limitation | Rapid CNS redistribution - seizures may recur 20-30 min after administration. MUST follow with phenytoin |
| IV formulation | Contains propylene glycol - tissue irritant; avoid IM route (erratic absorption) |
C. MIDAZOLAM
| Feature | Details |
|---|
| Indication | When IV access unavailable; preferred buccal/IM route in pre-hospital and paediatric setting |
| Dose IM | 0.2 mg/kg IM (max 10 mg) - FASTEST administration when no IV |
| Dose buccal | 0.3-0.5 mg/kg (max 10 mg) - useful in children |
| Dose IV (refractory SE) | 0.2 mg/kg loading dose, then 0.1-0.4 mg/kg/h infusion |
STEP 2 (20-40 MIN): SECOND-LINE ANTICONVULSANTS
A. PHENYTOIN / FOSPHENYTOIN
| Feature | Details |
|---|
| Indication | After benzodiazepines fail; or immediately after benzodiazepines to prevent recurrence (since diazepam redistributes quickly) |
| Mechanism | Blocks voltage-gated Na+ channels - reduces high-frequency neuronal firing |
| Contraindications | Sinus bradycardia, SA/AV/intraventricular block, Adams-Stokes syndrome, hypersensitivity |
| Dose | Phenytoin: 15-20 mg/kg IV at no faster than 25-50 mg/min (max 1 g) |
| Dilution | Phenytoin: dilute in normal saline ONLY (precipitates in dextrose). Fosphenytoin can be given in NS or D5W |
| Rate restriction | Faster infusion causes hypotension and cardiac arrhythmia (heart block, bradycardia). Monitor BP and ECG during infusion |
| Fosphenytoin advantage | Water-soluble prodrug - can be given IM; 3x faster infusion (50-75 mg phenytoin equivalents [PE]/min); less phlebitis |
| Post-load check | Check phenytoin level 2 h after load; target 20-25 mcg/mL |
B. VALPROATE (Sodium Valproate)
| Feature | Details |
|---|
| Indication | Second-line alternative to phenytoin; preferred in myoclonic or absence SE, and if phenytoin contraindicated |
| Mechanism | Blocks Na+ and T-type Ca2+ channels; enhances GABA synthesis |
| Contraindications | Liver disease, pancreatitis, urea cycle disorders, pregnancy (teratogenic - spina bifida), porphyria |
| Dose | 20-40 mg/kg IV at 3-6 mg/kg/min |
C. LEVETIRACETAM
| Feature | Details |
|---|
| Indication | Increasingly used as 2nd-line for SE; good safety profile, no hepatotoxicity, no significant drug interactions |
| Mechanism | Binds SV2A synaptic vesicle protein, modulates neurotransmitter release |
| Contraindications | Hypersensitivity. Dose-reduce in renal failure |
| Dose | 60 mg/kg IV over 10 min (max 4.5 g) |
STEP 3 (>60 MIN): REFRACTORY STATUS EPILEPTICUS - ICU with EEG monitoring
A. PROPOFOL
| Feature | Details |
|---|
| Indication | Refractory status epilepticus requiring anaesthetic induction |
| Mechanism | Potentiates GABA-A receptor; direct inhibitory effect |
| Dose | 2 mg/kg IV bolus, then 2-10 mg/kg/h infusion |
| Warning | Propofol infusion syndrome with high doses (>5 mg/kg/h) for >48h - metabolic acidosis, rhabdomyolysis, cardiac failure, death. Monitor lactate and CPK |
B. PENTOBARBITAL / THIOPENTONE
| Feature | Details |
|---|
| Indication | Last resort for super-refractory SE (>24h of refractory SE) |
| Mechanism | Barbiturate - activates GABA-A receptors AND directly inhibits glutamate receptors |
| Dose | Pentobarbital: 10 mg/kg/h; adjust to burst-suppression on EEG |
SPECIAL CASES WITHIN SE:
| Cause | Treatment |
|---|
| Eclamptic seizures | IV magnesium sulphate 4 g over 5-10 min loading dose; NOT standard anticonvulsants as first-line |
| Isoniazid (INH) overdose | IV pyridoxine (Vitamin B6) 1 g per gram of INH ingested - seizures refractory to benzodiazepines without pyridoxine |
| Hyponatraemia | Hypertonic saline 3% IV 100-150 mL bolus |
| Hypoglycaemia | Dextrose 50% 50 mL IV (+ thiamine 100 mg IV first if Wernicke's risk) |
QUICK REFERENCE SUMMARY TABLE
| Condition | 1st Drug | 2nd Drug | Key Pitfall |
|---|
| Cardiac arrest (VF/pVT) | Defibrillation + Epinephrine 1 mg IV | Amiodarone 300 mg IV | Don't stop CPR to give drugs |
| Cardiac arrest (PEA/Asystole) | Epinephrine 1 mg IV every 3-5 min | Treat reversible causes (4H/4T) | Atropine is no longer recommended |
| Anaphylaxis | Epinephrine 0.5 mg IM (1:1,000) in outer thigh | IV fluids, salbutamol nebuliser | Never delay epi for antihistamines |
| Hypertensive emergency | Nicardipine 5 mg/h IV OR Labetalol 20 mg IV bolus | Sodium nitroprusside | Never normalize BP acutely (>25% reduction is harmful) |
| Acute severe asthma | Salbutamol 5 mg nebulised continuously | Add ipratropium + IV hydrocortisone + MgSO4 2 g | Silent chest = near-fatal, intubate early |
| Status epilepticus | Lorazepam 0.1 mg/kg IV (max 4 mg) | Phenytoin 20 mg/kg IV in NS | Phenytoin in dextrose = precipitation |
CRITICAL ROUTE SUMMARY: "NEVER FORGET"
- Epinephrine in anaphylaxis = 1:1,000 IM (outer thigh). Never IV unless cardiac arrest
- Epinephrine in cardiac arrest = 1:10,000 IV push (1 mg)
- Phenytoin = NS ONLY, slow rate, ECG monitoring
- Amiodarone = D5W ONLY (precipitates in NS)
- Nitroprusside = foil-wrapped bag, cyanide monitoring
- MgSO4 = slow (20 min), antidote is calcium gluconate
Sources: Rosen's Emergency Medicine (9th Ed.), Tintinalli's Emergency Medicine (9th Ed.), Adams & Victor's Principles of Neurology (12th Ed.), Comprehensive Clinical Nephrology (7th Ed.), Katzung's Basic and Clinical Pharmacology (16th Ed.), Goodman & Gilman's Pharmacological Basis of Therapeutics
