What are the common emergency drugs and their doses for a general adult patient population with no specific medical history or allergies?

Common Emergency Drugs and Doses for Adults

The most critical emergency medications with standardized adult dosing are epinephrine 1 mg IV/IO every 3-5 minutes for cardiac arrest, naloxone 0.2-2 mg IV/IO/IM for opioid overdose, and atropine 0.5-1 mg IV every 3-5 minutes (up to 3 mg) for bradycardia or organophosphate poisoning. 1

Cardiac Arrest Medications

Epinephrine

• Initial dose: 1 mg IV/IO every 3-5 minutes during cardiac arrest 1
• For endotracheal administration (only when IV/IO access unavailable): 2-3 mg maximum due to depot effect risks, though this route is significantly less effective than IV 2, 3
• Continue dosing every 3-5 minutes throughout resuscitation efforts 1

Atropine

• Bradycardia/cardiac indications: 0.5-1.0 mg IV every 3-5 minutes up to 3 mg total 1
• Note: The 2015 guidelines removed routine atropine recommendation for cardiac arrest, though some evidence suggests benefit in non-shockable rhythms when combined with epinephrine 4

Amiodarone

• Antiarrhythmic for ventricular fibrillation/pulseless VT (specific dosing in cardiovascular protocols) 1

Adenosine

• Antiarrhythmic for supraventricular tachycardia (specific dosing in cardiovascular protocols) 1

Overdose/Toxicology Antidotes

Naloxone (Opioid Reversal)

• Initial dose: 0.2-2 mg IV/IO/IM 1
• Titrate to reversal of respiratory depression, not full consciousness 1, 5
• Maintenance infusion: Two-thirds of the waking dose per hour 1
• Critical: Administer naloxone first in suspected combined opioid-benzodiazepine overdose before considering other antidotes 5
• Can be given endotracheally if no IV access, though less effective 6

Flumazenil (Benzodiazepine Reversal)

• Initial dose: 0.2 mg IV, titrated up to 1 mg maximum 1
• Major contraindications: Benzodiazepine dependence, seizure disorders, suspected cyclic antidepressant co-ingestion (risk of seizures and dysrhythmias) 1, 5
• Use only in select patients with pure benzodiazepine poisoning without contraindications 5
• Does not fully reverse respiratory depression in mixed overdoses 1

Atropine (Organophosphate/Carbamate Poisoning)

• Initial dose: 1-2 mg IV, doubled every 5 minutes 1
• Maintenance infusion: 10-20% of total loading dose per hour up to 2 mg/h 1
• Titrate to reversal of bronchorrhea, bronchospasm, bradycardia, and hypotension 1
• Pediatric dose: 0.02 mg/kg, doubled every 5 minutes 5

Calcium (Calcium Channel Blocker/Beta-Blocker Overdose)

Calcium Chloride:

• Initial dose: 2000 mg (20 mL of 100 mg/mL solution) = 28 mEq Ca²⁺ 1
• Maintenance infusion: 20-40 mg/kg/h 1
• Administer through central line, especially in children 1
• Titrate to blood pressure; do not exceed ionized calcium 1.5-2× upper normal limit 1

Calcium Gluconate:

• Initial dose: 6000 mg (60 mL of 100 mg/mL solution) = 28 mEq Ca²⁺ 1
• Maintenance infusion: 60-120 mg/kg/h 1
• Can be given peripherally (less tissue damage than calcium chloride) 1

Glucagon (Beta-Blocker/Calcium Channel Blocker Overdose)

• Initial dose: 2-10 mg IV 1
• Maintenance infusion: 1-15 mg/h 1
• Anticipate vomiting as common side effect 1

High-Dose Insulin (Beta-Blocker/Calcium Channel Blocker Overdose)

• Initial dose: 1 unit/kg regular human insulin IV 1
• Maintenance infusion: 1-10 units/kg/h 1
• Monitor closely for hypoglycemia, hypokalemia, and volume overload 1

Digoxin Immune Fab

• Acute overdose: 1 vial for every 0.5 mg digoxin ingested 1
• Critically ill with unknown dose: 10-20 vials 1
• Each vial contains 40 mg Fab; lower doses may be equally effective 1

Methylene Blue (Methemoglobinemia)

• Initial dose: 1-2 mg/kg IV, repeated every hour if needed 1
• Maximum total dose: 5-7 mg/kg 1
• Also used for vasodilatory shock from calcium channel blockers: 1 mg/kg/h infusion 1

Intralipid Emulsion (Local Anesthetic Toxicity)

• Initial bolus: 1.5 mL/kg (up to 100 mL) of 20% lipid emulsion 1
• Maintenance infusion: 0.25 mL/kg/min for up to 30 minutes 1

Anaphylaxis

Epinephrine (First-Line)

• Dose: 0.3-0.5 mg IM (1:1000 concentration) into anterolateral thigh 7
• This is the absolute first-line treatment; never delay for antihistamines 7
• Repeat every 5-15 minutes as needed 7

Adjunctive Medications (After Epinephrine)

• Diphenhydramine: 25-50 mg IV/IM (H1-antihistamine) 7
• Famotidine: 20 mg IV (H2-antagonist; onset ~1 hour, does not relieve respiratory symptoms) 7
• Crystalloid fluid bolus: 1-2 liters IV for hypotension 7

Respiratory Emergency Medications

Albuterol (Bronchospasm)

• Nebulized: 2.5-5 mg in 3 mL normal saline 1
• Can repeat every 20 minutes for severe bronchospasm 1

Ipratropium Bromide

• Nebulized: 0.5 mg combined with albuterol 1

Seizure Management

Benzodiazepines (First-Line)

Midazolam:

• IM dose: 5 mg (faster onset than lorazepam: 18.3 min vs 32.2 min to sedation) 1
• Shorter duration of action (82 min to arousal vs 217 min for lorazepam) 1

Lorazepam:

• IV dose: 2-4 mg 1
• Longer duration of action, preferred for sustained seizure control 1

Diazepam:

• IV dose: 5-10 mg 1
• Should NOT be given endotracheally (ineffective absorption) 6

Agitation/Behavioral Emergency Medications

Combination Therapy (Most Effective)

• Haloperidol 5-10 mg IM + Promethazine 25-50 mg IM: Produces more rapid tranquilization (15-30 min) than monotherapy 1
• Haloperidol 5 mg IM + Lorazepam 2 mg IM: Superior to lorazepam alone 1

Monotherapy Options

• Haloperidol: 5-10 mg IM (mean time to sedation: 28.3 min) 1
• Midazolam: 5 mg IM (fastest onset: 18.3 min, but shortest duration) 1
• Lorazepam: 2-4 mg IM (mean time to sedation: 32.2 min) 1

Metabolic Emergencies

Dextrose (Hypoglycemia)

• 50% Dextrose: 25-50 mL (12.5-25 g) IV push 1
• For pediatrics: Dilute to 25% or use D10W at 2-4 mL/kg 1

Sodium Bicarbonate

• Dose: 1 mEq/kg IV for severe metabolic acidosis or tricyclic antidepressant overdose 1

Magnesium Sulfate

• Dose: 1-2 g IV over 5-15 minutes for torsades de pointes or severe asthma 1

Critical Pitfalls to Avoid

• Never use endotracheal drug administration as first choice—IV/IO routes are significantly more effective; ET epinephrine and atropine at currently recommended doses (2× IV dose) are rarely effective during cardiac arrest 3
• Never delay epinephrine for antihistamines in anaphylaxis—epinephrine is the only life-saving medication 7
• Never give flumazenil without screening for contraindications—can precipitate life-threatening seizures and dysrhythmias 1, 5
• Never give calcium through peripheral IV in children—use central access to avoid tissue necrosis 1
• Never assume benzodiazepine tolerance persists indefinitely—tolerance wanes with abstinence, converting patients back to opioid-naïve status 8
• Always give naloxone first in suspected combined opioid-benzodiazepine overdose—opioid reversal takes priority given current epidemic of fentanyl-adulterated drugs 1, 5