Executive Summary
N-Acetylcisteine (NAC) is a mucolytic, antioxidant and a glutathione-inducer. It is positioned as the cornerstone antidote for the prevention and treatment of liver toxicity secondary to acetaminophen (APAP) overdose, with US-FDA approval for IV, PO and effervescent tablets administration.

Adult and Pediatric dose for acetaminophen overdose: oral administration, 18 doses total. 

• Loading dose: 140mg/kg PO.

• Dose 2 to 17: repeated doses every 4 hours of 70mg/kg PO.

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Executive Summary
Acetylsalicylic acid (ASA), also known as aspirin, is an NSAID with analgesic and anti-inflammatory effects that inhibit platelet aggregation. It is frequently prescribed in EDs worldwide as part of the standard treatment for acute coronary syndromes and other acute vascular conditions.

• To date, ASA is not commonly utilized as an analgesic or anti-inflammatory agent. Other NSAID alternatives, such as ibuprofen, exhibit significantly lower effects on platelet anti-aggregation and pose a lower risk of bleeding. An exception is observed in patients with coronary artery disease experiencing acute pericarditis.

• ⚠ Cautions: increased risk of bleeding, kidney injury and peptic ulcer disease. Adverse effects usually manifest at analgesic doses (300-600 mg every 4-6 hours), and rarely at lower antiaggregatory doses (≈100 mg/day).

Adult dose for acute coronary syndromes

• Loading dose: 162 to 325 mg PO.

• Maintenance dose (beginning on the next day): 75 to 100 mg/day PO.

Adult dose for acute ischemic stroke, transient ischemic attack
⚠ Delay antiplatelet therapy for at least 24 hours in patients who have undergone IV fibrinolysis (alteplase or tenecteplase) and have had a control CT scan to rule out hemorrhagic conversion. Standard of care should involve consulting a vascular neurologist to guide treatment.

When hemorrhagic stroke has been ruled out in patients not eligible for fibrinolytic therapy, initiate aspirin therapy as soon as possible.

• First dose: 160 to 300 mg PO.

• Maintenance dose: 75-100 mg/day PO.

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Executive Summary
Activated charcoal is a nonspecific adsorbent extensively used in EDs to reduce the absorption and prevent the enterohepatic recirculation of various toxic substances and drug overdoses.

• There is a tendency to use it in a more rational fashion, balancing potential benefits with risks. Ideally, it should be administered within 1 hour of ingestion; however, this limit may vary in cases involving extended-release forms of ingested xenobiotics and other exceptions. 

  • AC is indicated for toxic doses of acetaminophen, aspirin, antidepressants, antipsychotics, antiepileptic drugs, calcium channel blockers, beta-blockers, etc. 

• ⚠ Cautions: evaluate the level of consciousness and airway to prevent aspiration; secure the airway before administration if necessary. Activated charcoal is contraindicated in cases of gastrointestinal obstruction or perforation.

  • Not useful in acids, alkali, alcohols, hydrocarbons, heavy metals, pesticides, etc. 

Adult single dose of AC for acute poisoning / drug overdose

• 1 gr/kg PO. 

• Dilute in water or flavored juice.

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Executive Summary
Adenosine is an endogenous nucleoside present in all human cells. It is categorized as a “class V” or “miscellaneous” antiarrhythmic agent, as it does not meet the criteria for inclusion in antiarrhythmic classes I, II, III, or IV.

• Adenosine is the first-line medication for stable paroxysmal supraventricular tachycardia (PSVT) unresponsive to vagal maneuvers, commonly used in EDs worldwide.

• It decreases conduction through the AV node, thereby terminating the PSVT in 90% of cases.

• Always administer adenosine in the resuscitation room with continuous monitoring and a defibrillator at hand. 

• ⚠ Cautions: 

  • Contraindications: 2nd or 3rd AV block, sinus node disease and symptomatic bradycardia, and irregular wide-complex tachycardia as it may trigger ventricular fibrillation.

  • Interactions: use with extreme caution if the patient has received other antiarrhythmics or AV blocking agents. 

  • Adverse effects: flushing, dizziness, shortness of breath, chest pain or discomfort, transient hypotension, etc. Various self-limited arrhythmias, AV blocks, or prolonged sinus pause  at the time of sinus conversion. It may cause bronchoconstriction. 

Adult dose for paroxysmal supraventricular tachycardia

“6-12-12 mg”

• Initial dose: 6 mg IV given as a rapid bolus, immediately followed by a vigorous flush of normal saline.

• If a second dose is needed: 12 mg IV as a rapid bolus.

• If a third dose is needed: 12 mg IV as a rapid bolus.

• Consider other cardioversion strategies and alternative diagnoses  if 3 doses of adenosine do not work.

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Executive Summary
Alteplase, a fibrin-specific Tissue Plasminogen Activator (fibrinolytic) is widely accepted for emergency revascularization in acute myocardial infarction (MI),  high risk acute pulmonary embolism (PE), and acute ischemic stroke (AIS). 

• In emergency medicine it is also used in  intermediate-high risk PE and cardiac arrest when there is a high suspicion of MI or PE as the cause, in both scenarios the decision should be taken cautiously and in very selected cases.

• Always seriously consider the contraindications and balance the risk of intracranial and other major bleeding events versus the benefit of the therapy. Fibrinolysis is an intervention that should be decided -or at least supported- by a specialist (emergency medicine, neurologist, cardiologist, intensivist). 

Acute Coronary Syndrome with ST elevation (<12 hours)

US-FDA approved

Adult dose:

• ≤67kg: 15mg bolus + 0.75mg/kg in next 30 min

• >67kg: 15 mg bolus + 50 mg in 30 min + 35 mg in 60 min

Acute Ischemic Stroke (<4.5 hours)

US-FDA approved for <3 hours after symptom onset (1996), Universally accepted use in <4.5 hours.
Adult dose:

• <100kg:  0.9mg/kg total (max 90mg)

  • 10% bolus over 1 min

  • 90% infusion over 60 min

• ≥100kg: 9mg bolus + 81mg 60min

Pulmonary Embolism

US-FDA approved. 

Adult dose: 

• Intermediate risk: 50mg in 2 hrs

• High risk: 100mg in 2 hrs

• Cardiac arrest: 50mg bolus + 50mg if no ROSC in 15 min

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Executive Summary

Amiodarone is classified as a class III antiarrhythmic, affecting all phases of the action potential by inhibiting K+ efflux channels, Na+ channels, and L-type Ca2+ channels. Furthermore, it exhibits a non-competitive blockade action on beta receptors, resulting in a potent antiarrhythmic effect.

• Most ED use involves the treatment of ventricular and supraventricular arrhythmias. In-depth knowledge of these conditions and alternative effective treatments beyond amiodarone is necessary:

  • Cardiac arrest (VF and pulseless VT)

  • Ventricular tachycardia (VT)

  • Atrial fibrillation/flutter

  • Electrical storm

• ⚠ Cautions summary: 

  • Hypotension, bradydysrhythmias, and QT interval prolongation are the most common and relevant adverse reactions associated with acute use. Additionally, it has several long-term and chronic complications, including pulmonary, hepatic, thyroid and ocular issues.

  • It should not be used in patients with atrial fibrillation who have not been previously anticoagulated and in whom atrial thrombi have not been ruled out due to the risk of periprocedural cardioversion embolization and stroke, with a risk as high as 3-6%.  

Adult dose for cardiac arrest with shockable rhythms (VF and Pulseless VT (pVT))

It is only recommended in cases of persistent VF/pVT despite defibrillation attempts and the administration of epinephrine (see ACLS algorithm):

• Initial dose: 300 mg of amiodarone IV or IO for patients who remain in VF or pVT after three defibrillation attempts.

• Additional dose: 150 mg IV or IO if persistent VF/pVT after a total of five shocks.

Adult dose for stable ventricular tachycardia

• Loading dose: 150 mg IV diluted in 100 ml 5% dextrose over 30 min.

• Continuous infusion: after loading dose, initiate infusion of 1 mg/min for 6 hr, then 0.5 mg/min for 18 hr.

• After initial IV administration, consider initiation of 400 mg every 8-12 hours for 1-2 weeks, then 300–400 mg daily; reduce dose to 200 mg daily if possible.

• Consider procainamide as the first-line antiarrhythmic for monomorphic VT.

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Executive Summary

Calcium gluconate is the calcium salt of gluconic acid. It is used intravenously to rapidly increase the blood calcium levels, as it plays a crucial role in various physiological processes such as heart function and nerve impulse conduction.

• In the ED, calcium gluconate is mainly used for the acute management of symptomatic severe hypocalcemia and in patients with severe hyperkalemia, as both of these conditions carry a high risk of arrhythmias. 

• ⚠ Cautions: contraindicated in hypercalcemia. Caution in hyperphosphatemia. May increase digoxin toxicity.
   

Adult dose for acute severe hypocalcemia

1-2 gr IV over 10 min, may be repeated every 10-60 min if necessary.

Adult dose for severe/emergent hyperkalemia

1-2 gr IV over 2-5 min, may be repeated every 15-30 min if needed (persistent EKG signs of hyperkalemia, AV blockade, etc).

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Executive Summary
Ciclobenzaprine is a centrally acting skeletal muscle relaxant widely prescribed to relieve acute painful musculoskeletal conditions as an adjunct treatment to physical therapy  and rest. It is also used as a temporary adjuvant medication along with non-steroidal anti-inflammatory drugs (NSAIDs) or acetaminophen. 

• Limited data supports its use in the short term for treating  acute muscle spasm, acute low back pain, fibromyalgia  and temporomandibular disorder.

• Muscle relaxants including cyclobenzaprine have significant adverse effects on the central nervous system (sedation, drowsiness, dizziness), therefore, they should be prescribed with caution and their benefits need to be balanced with their risks; experts differ on whether they should be used or not.

• It has a similar structure to tricyclic antidepressants such as amitriptyline, thus  it can cause serious anticholinergic effects, but no direct cardiotoxicity has been reported in cases of overdose (eg. sodium channel blockade and QRS complex widening).

Adult dose for acute painful musculoskeletal spasms

Immediate release formulation*

• 5mg TID with one dose at night.

• Maximum 30mg/day, up to 2-3 weeks.

*Many clinicians start at a low dose at night (5mg) and then titrate up if it is strictly necessary.

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Executive Summary

Dobutamine, a synthetic catecholamine, is one of the most studied and used inotropic agents in cardiovascular critical care for the treatment of cardiogenic shock (CS), with approval of the US-FDA for that condition. 

• USA and European guidelines recommend norepinephrine as first-line vasopressor to manage hypotension in CS (3, 6). Subsequently, if needed, an inotrope and/or mechanical cardiovascular support (MCS) may be added to improve perfusion and facilitate definitive intervention. 

• It has inodilator properties as a beta-receptors agonist (𝛽1 and 𝛽2), with subsequent positive chronotropism, inotropism and mild peripheral vasodilation. This may provoke myocardial ischemia, arrhythmias and severe cardiovascular events. Use with extreme caution. 

• Dobutamine is preferred over epinephrine for CS, as the latter is associated with an increased risk of refractory shock, lactic acidosis and mortality.

Adult dose for cardiogenic shock

2-20 ug/kg/min

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Executive Summary

Droperidol is a first generation antipsychotic (so-called typical antipsychotics, same class as haloperidol) that acts as a D2 dopamine receptor antagonist. Droperidol also has some histamine and serotonin antagonist properties. 

• It has a significant potential role in the ED because of its efficacy to treat a variety of clinical conditions, including undifferentiated agitation, migraine, vertigo, nausea, vomiting, cannabinoid hyperemesis, and pain.

• The US-FDA issued a Black Box Warning in 2001, but has been deeply questioned. This is why the drug has been regaining popularity and its use has been increasing over the last decade. Nonetheless it should not be used on patients with long QT syndrome or at an increased risk of QT prolongation. 

Adult dose for undifferentiated agitation in the ED

5-10mg IM

Adult dose for migraine, acute vertigo, nausea or vomiting and cannabinoid hyperemesis

1.25-2.5mg IV or IM

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Executive Summary
Etomidate is an ultrashort-acting, non-barbiturate hypnotic intravenous anesthetic agent. Is one of the most used and preferred hypnotic agents in the ED for Rapid Sequence Intubation. 

• Etomidate acts on GABA receptors moderating the activity of chloride channels; it makes  neurons less excitable without any major cardiovascular impact.

• It causes an adrenal inhibition of corticosteroid synthesis, therefore only a single  bolus dose is recommended for induction to minimize adrenal suppression. 

Pharmacology for a single bolus administration:

• Onset: 15-45 seg

• Time to Peak Effect: 45 seg

• Duration of hypnotic effect: 3-12 min

Adult dose for rapid sequence intubation:  

0.3mg/kg IV (total body weight).

• Consider a lower dose of 0.2mg/kg in profound shock. 

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Executive Summary

Epinephrine is an endogenous catecholamine non-selective agonist of all adrenergic receptors with a major role in emergency medicine on a variety of different diagnoses. 

• Anaphylaxis
  Epinephrine acts on several pathophysiological pathways that cause anaphylaxis . It is the only established therapy to treat this condition.

• Cardiac arrest (CA)
  Current guidelines include epinephrine as part of standard treatment during CA in children and adults, being the only recommended drug regardless of initial rhythm mainly because it is associated with an increased rate of ROSC* and short-term survival. 

• Severe asthma crisis
  Consider IV or IM epinephrine in the crashing asthmatic patient to deliver a systemic Beta-2 agonist agent (when inhaled bronchodilators have trouble getting into the lower airway). Give as a push-dose if administered IV, and an equivalent anaphylaxis dose for IM administration.

*ROSC: Return of Spontaneous Circulation

Adult dose for anaphylaxis
0.01mg/kg (max 0.5mg per dose) IM into the anterolateral aspect of the thigh.

• Can be repeated every 5-15 min if necessary.

• If there is no response, consider a continuous IV infusion of epinephrine.

Adult dose for cardiac arrest
1mg every 3 to 5 minutes IV or IO

• In shockable rhythms early defibrillation should be performed as soon as possible, before any other resuscitation interventions

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Executive Summary

Racepinephrine is a mixture of epinephrine's L- and D- isomers. It is used nebulized as an effective and safe treatment for croup (acute laryngotracheitis) in pediatric patients, acting as a local vasoconstrictor to alleviate swelling and edema. 

• While L-epinephrine has been proven safe and effective when administered via nebulization for croup, racepinephrine is considered by many experts and institutions as the first-line inhaled vasoconstrictor agent for the treatment of moderate to severe croup. 

• Comparing racepinephrine with L-epinephrine, evidence has shown that there is no difference in croup score after 30 minutes of treatment. On the contrary, a better outcome has been observed after 120 minutes, favoring L-epinephrine.
  
  

Pediatric dose for moderate to severe croup (acute laryngotracheitis)

Nebulization of 0.05 ml/kg per dose (max 0.5 ml), diluted to 3 ml with normal saline.

• Same dose may be repeated every 15 to 20 minutes as needed. 

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Executive Summary
Fentanyl is a potent opioid pain medication that is extensively used in the ED to manage severe acute pain and as premedication to intubation preparation.

• In the ED is usually preferred over other opioids (eg. morphine) due to its higher potency,  faster onset of action, and shorter duration of action. This makes it useful to precisely titrate dosing in the acute setting. Additionally, it has a safer hemodynamic profile than morphine, causing less hypotension or cardiac instability.

• ⚠ Cautions summary: 

  • High risk of respiratory depression (black box warning) and other adverse effects; it should be used with caution, monitoring closely for respiratory depression, hypotension, sedation and other adverse effects. 

  • High risk of addiction and overdose (black box warning): Its use should be limited to the management of short-term acute pain and critical care support.
    
    

Adult dose for moderate to severe pain:

1 mcg/kg/dose (usually 50-100 mcg) IV.

• Repeat in 1 to 2 hours as needed (label recommendation).

• Consider repeat doses in 5-10 min in cases of excruciating pain (emergency medicine practice).

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Executive Summary

Flavoxate is a synthetic anticholinergic with urinary tract spasmolytic activity that is used for symptomatic alleviation in genitourinary conditions such as lower urinary tract infection, prostatitis, and urethritis.

• It does not have antibiotic properties, and should never be used as a replacement for appropriate antimicrobials.

• It should not be prescribed to patients with an increased risk of intestinal obstruction, ileus, or urinary retention, or any other conditions that may be aggravated by anticholinergic agents.
  
  

Adult dose for symptomatic relief of urinary urgency, suprapubic pain secondary to UTIs 

100-200mg every 6 to 8 hours PO

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Executive Summary

Unfractionated heparin (UFH) is an endogenous anticoagulant that enhances antithrombin, ultimately preventing the conversion of fibrinogen to fibrin. It can be reversed by protamine.

• UFH and other anticoagulants are extensively used in the ED for many thrombotic-related events, such as venous thromboembolism (VTE) – including acute pulmonary embolism (PE) and deep venous thrombosis (DVT) – acute coronary syndrome, acute limb ischemia, mesenteric thrombosis, etc.

• There has been a clear tendency to replace UFH with low molecular weight heparins (LMWH) due to their predictable effects, easier administration, and monitoring advantages. 

• Preference of UFH over LMWH:

  • High-risk pulmonary embolism.

  • Myocardial infarction with ST segment elevation.

  • Severely impaired renal function.

• ⚠ Always evaluate the hemorrhagic risk before initiating anticoagulant therapy.
  
  

Adult dose for pulmonary embolism

• 80 IU/kg bolus IV followed by a 18 IU/kg/hr infusion.

• UFH is preferred over LMWH for high-risk PE. For low and intermediate-risk PE, consider LMWH or oral anticoagulation alternatives.

Adult dose for ST-segment elevation myocardial infarction (STEMI)

• Primary PCI*:
  70 IU/kg bolus IV (max 5000 IU).

• Fibrinolysis:
  60 IU/kg bolus IV (max 4000 IU) followed by 12 IU/kg/hr infusion (max 1000 IU/hr), continue until PCI. 

*Percutaneous coronary intervention

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Executive Summary

Hypertonic saline solutions (HTS) are electrolyte concentrates of NaCl (over 0.9%) and  considered to be high alert medications that are cautiously used to treat symptomatic hyponatremia and acute intracranial hypertension (IH) secondary to multiple causes, but mainly to traumatic brain injury. 

• Recent reviews comparing mannitol versus HTS tend to favor the latter with a weak level of evidence. 

• Ideally HTS should be administered through a central venous access, but in emergency situations, peripheral infusions have been determined to be a safe short-term alternative, but a close monitoring of the clinical response and sodium levels is warranted to guide subsequent doses.  

Adult dose for acute intracranial hypertension caused by TBI

NaCl 3%, 2 ml/kg IV in 15 minutes bolus

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Ibuprofen is the most extensively studied NSAIDs for the treatment of acute pain and is prescribed worldwide in EDs for both pediatric and adult patients.

• It is the only intravenous NSAID approved by the US-FDA for the treatment of both fever and pain (while other IV NSAIDs are approved solely for pain management). IV ibuprofen has the disadvantage of requiring a slow 30-min infusion.

• Pediatrics: with acetaminophen, it is considered a first-line analgesic for this population.

  • The US-FDA has approved the use of intravenous ibuprofen starting at the age of 3 months and oral formulations starting from 6 months of age.

• ⚠ Cautions: 

  • Usual NSAIDS adverse effects: cardiovascular thrombotic events, gastrointestinal bleeding (ulceration, perforation), heart failure, renal toxicity, etc. 

  • Fetal toxicity: premature closure of fetal ductus arteriosus, neonatal renal impairment (avoid in pregnancy).

Adult dose for pain or fever

400-800 mg IV or PO over 30 min every 6-8 hours as needed (maximum 3200 mg/day).

• When given IV it should be infused over 30 min.

• Individual doses of 400 mg and a cumulative daily dose of 1200-2400 may be the analgesic  ceiling for acute pain management.

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Executive Summary

Ketamine, a dissociative and analgesic agent, has seen a notable surge in its usage within the ED over the past decade. It is employed as an induction agent for endotracheal intubation, procedural analgosedation, management of agitation, and acute pain relief.

• Ketamine may be considered as an alternative to etomidate as an induction agent for hemodynamically unstable patients, but it is associated with a higher incidence of peri-intubation hypotension compared to etomidate.

• Low-dose ketamine (0.2-0.5 mg/kg IV) has been found to be equally effective as morphine in the management of acute pain within the ED, demonstrating comparable safety profiles.

• A thorough understanding of ketamine's pharmacological properties and potential adverse effects is essential for its appropriate usage. Continuous monitoring is imperative during its administration.

• ⚠ Cautions: respiratory depression, neuropsychiatric symptoms, hypertension and tachycardia, hypotension, laryngospasm, and potential dependence with prolonged use.

Adult dose for endotracheal intubation induction

1.5-2 mg/kg IV.

Adult dose for procedural sedation and analgesia

0.3-1 mg/kg IV.

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Executive Summary

Ketorolac is an NSAID with a potent analgesic effect that is very frequently indicated in the ED worldwide to treat moderate to severe acute pain. 

• The US-FDA labeling recommends usage only for moderate to severe pain (defined as requiring analgesia at the opioid level), and for a short period of time of no more than 5 days to reduce NSAIDs adverse effects.

• Ketorolac, as well as other NSAIDs, reduces opioid requirements for acute pain.

Adult dose for acute moderate to severe pain

• IV: 10 to 30mg every 6 hours IV (max 120mg/day)*

• PO: 10mg every 6 hours PO (max 40mg/day)

*adults ≥65 years: max 60mg/day

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Executive Summary

Levetiracetam (LEV) is a second generation antiepileptic drug (AED) that has gained popularity in the ED for the treatment of status epilepticus (with a conjunction of benzodiazepines, usually IV lorazepam or IM midazolam); 

• It modulates neuronal activity through GABA and high-voltage-dependent calcium channels, by unknown molecular mechanisms.

• In children and adults, compared with other AED, LEV has a similar efficacy treating SE, with an excellent safety profile (most studies comparing it with phenytoin).

• EMDrugs is currently reviewing evidence regarding LEV usage for seizure prophylaxis in subarachnoid hemorrhage. 

Adult dose for status epilepticus

• Loading dose of 60 mg/kg IV (max 4,500 mg) in 15 minutes.

• Maintenance dose of 1 gr every 12 hours IV or PO (up to a maximum of 3 gr/day).
  
  

Adult dose for post-traumatic seizure prophylaxis in severe TBI

• Loading dose of 1000 mg IV.

• Maintenance of 500 to 1000 mg every 12 hours (IV or PO).

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Executive Summary
Lidocaine is a synthetic local anesthetic, and one of the most frequently used drugs in the ED.  It has a reversible blocking effect on voltage-gated sodium channels, resulting in two main clinical usages: (i) interrupting nerve impulse propagation to achieve local or regional anesthesia, and (ii) inhibition of cardiac ion channels as a class IB antiarrhythmic drug. 

• Lidocaine has a wide variety of specific applications in the ED: 

• Antiarrhythmic for ventricular tachycardia

• Local and regional anesthesia for wound repair and fracture closed reductions

• Pain management for severe painful conditions such as renal colic and headache 

• Topical –spray or gel– anesthesia for awake intubation and other procedures such as bladder catheterization 

• Symptomatic treatment of cough

• Transdermal patches to alleviate post-herpetic neuralgia and rib fractures

Adult dose for local anesthesia

Up to 4.5 mg/kg (max 300mg per dose) subcutaneous infiltration within 2 hours.

• Dosing calculator: MDCalc®   - Local Anesthetic Dosing Calculator

Adult dose for ventricular tachycardia (8, 9)

1-1.5mg/kg IV.

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Executive Summary

Intravenous lipid emulsion (IVLE) is a nutritional supplement approved by the US-FDA for parenteral nutrition, that have promising results for the treatment of lipophilic agents toxicity, mostly for local anesthetic systemic toxicity (LAST).

• In conjunction with advance cardiovascular and neurocritic support, toxicologists and AHA guidelines consider IVLE as a valid therapeutic option to treat LAST, particularly in severe cases (eg. cardiovascular collapse / arrest).

Adult dose for Local Anesthetic Systemic Toxicity (LAST)

Intralipid® 20%, 1,5 ml/kg IV bolus over 1 minute (approximately 100ml in adults), followed by an infusion of 0.25ml/kg/min IV over the next 30-60 minutes.

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Executive Summary
Lorazepam is an intermediate acting benzodiazepine (BDZ) –a GABA receptor enhancer– with CNS depressant effects including sedative, hypnotic, skeletal muscle relaxing and anticonvulsant activity. It can be administered either by intravenous, intramuscular, sublingual or oral routes. Along with midazolam and clonazepam, lorazepam is one of the most frequently indicated BDZs in the ED. 

Sedation timing with single 2-4mg dose:

• Intravenous

Onset (IV): 5-10 minutes*

Peak Effect (IV): 30 minutes

Duration (IV): 2-6 hours

(*shorter to terminate seizures)

• Intramuscular

Onset (IM) 15 minutes

Peak Effect (IM) 60 minutes

Duration (IM) 6-8 hours

Adult dose for status epilepticus:
0.1mg/kg IV (max 4mg/dose).

• Repeat every 5-10 min until the crisis has ceased.

• Consider initiating an antiepileptic if a second lorazepam dose is required. 

Adult dose for undifferentiated agitation:
2-4mg sublingual, IV or IM as needed (if severely agitated, IM route is prefered).

• Repeat every 20-30 min if necessary.

• The BDZ of choice to treat severe undifferentiated agitation is considered to be midazolam IM for its faster onset of action.

Acute anxiety disorder:

• 0.5-2mg sublingual, PO or IV as needed.

• Repeat every 20-30 minutes if necessary.

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Nitroglycerin (NTG) is a nitrate prodrug of nitric oxide (NO), which primarily produces vasodilation as its main cardiovascular effect.

• It is used sublingually and intravenously to treat angina pectoris secondary to coronary artery disease. In the ED, it is commonly indicated in hypertensive emergencies, particularly acute cardiogenic pulmonary edema (ACPE) and acute coronary syndromes.

• NTG use in ACPE is associated with a shorter hospital length of stay, lower intubation rates, and decreased ICU admissions.

• Vasodilatory effects: venous > arterial. Arterial vasodilation and afterload reduction are correlated with higher doses.

• ⚠ Cautions: NTG may cause severe hypotension. Contraindicated if the patient has used PDE-5 inhibitors (eg. sildenafil) within the previous 48 hours.
  
  

Adult dose for acute cardiogenic pulmonary edema

• Only consider NTG in hypertensive acute heart failure. 

• Intravenous

  • Start IV infusion at 0.5-0.7 μg/kg/min (approx. 30-50 μg/min for an adult) and titrate every 3-5 min with increases of 20-50 μg/min. Max dose of 400 μg/min. 

  • In severely symptomatic and hypertensive patients, consider high-dose boluses of 500 - 1000 μg every 3-5 min, followed by a continuous infusion. 

• Sublingual and oral spray

  • 400 μg, repeat every 5 min if needed.
    
    

Adult dose for angina and hypertension in acute coronary syndrome
5-10 μg/min infusion, titrate as needed (max 400 μg/min).

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Executive Summary
Naloxone is an opioid receptor antagonist extensively used in prehospital settings and EDs to reverse respiratory depression and coma in opioid-intoxicated patients.

• An intranasal spray formulation is also available for domestic and bystander administration, aimed at reducing preventable deaths associated with the ongoing public health issue of opioid abuse.

• ⚠ Cautions: a 'standard dose' may induce severe withdrawal symptoms in opioid-dependent patients, especially during IV administration. A lower dosing approach is recommended if opioid-dependence is suspected. 

• In the ED, it is crucial to prioritize the effective evaluation, assessment, and treatment of patients with coma and/or respiratory depression. Critical, time-dependent differentials include shock states, neurological disorders, toxic-metabolic conditions, and more. Proficiency in airway management is indispensable.
  
  

Adult dose for opioid overdose

• Non-opioid-dependent patients
  0.4 mg IV every 2 to 3 minutes until adequate spontaneous ventilation is achieved, up to a maximum of 10 mg. 

  • If the patient requires more than one dose or is at risk of further episodes of respiratory depression, a continuous infusion should be considered, or repeat doses every 1 to 2 hours.
    
    

• Opioid-dependent patients
  0.04 mg IV every 3 to 5 minutes until adequate spontaneous ventilation is achieved, up to a maximum of 2mg. 

  • A  significantly lower dose of naloxone should be considered to reverse hypoventilation and avoid withdrawal syndrome.

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Executive Summary
Norepinephrine (NE) is used for hemodynamic support frequently as a first-line vasopressor with the exception of anaphylaxis (epinephrine) and post cardiac arrest care (epinephrine). Consider using norepinephrine in combination with inodilator drugs in cardiogenic shock. 

Adult dose for shock:
0.01-0.3 μg/kg/min IV

• Usually started at 0.05 μg/kg/min IV

• Calculate with total body weight

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Executive Summary
Olanzapine is a second generation (atypical) antipsychotic with a potent antagonism of serotonin, dopamine, histamine and alpha1-adrenergic receptors. 

• In the ED, olanzapine  is frequently indicated as a first-line antipsychotic for acute agitation associated with psychiatric disorders.

• Agitation in the ED is a very complex situation that includes a variety of dissimilar scenarios with a wide range of therapeutic options. It is of great importance to be familiarized with the available therapeutic arsenal for agitation, such as droperidol, benzodiazepines, ketamine, etc. 

Adult dose for severe agitation:
5 to 10mg IM, repeated every 20 min if necessary

• Maximum of 30mg/day for intramuscular administration. 

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Executive Summary
Omeprazole is the most prescribed proton pump inhibitor (PPI) worldwide. It reduces gastric acid secretion by irreversibly blocking the H+/K+ ATPase enzyme within the gastric parietal cells.

• Globally, PPIs are commonly prescribed and administered in the ED for a variety of conditions, but there is no need to initiate PPI therapy within the first hours of emergency care, and no benefit has been proven in providing acute symptomatic relief in the ED. 

• The acute management of upper gastrointestinal bleeding in the ED typically involves the empiric administration of an IV PPI bolus. However, the benefits of emergent administration are questionable, as it does not reduce mortality, rebleeding, use of hemoderivatives, or need for surgery. On the other hand, it has been associated with a reduced incidence of high-risk stigmata of hemorrhage.

• Resuscitation and bleeding control of hemorrhagic shock should be prioritized, and the administration of omeprazole should not delay upper endoscopy or standard management for severe hemorrhage (eg., administration of hemoderivatives). 

Adult dose for peptic ulcer bleeding

• 80 mg IV, followed by 40 mg every 6 hours IV.

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Executive Summary

Ondansetron is a selective serotonin receptor antagonist (5HT-3) with proven antiemetic properties, used in both children and adults to treat nausea and vomiting caused by a variety of conditions; such as chemotherapy, gastroenteritis, migraine, traumatic brain injury, etc.

• Its use in the ED has increased significantly in the past decade, due to its effectiveness and fewer adverse effects than other antiemetic drugs. 

• When using multiple doses of ondansetron, a major concern is the risk of QT interval prolongation and subsequent potential arrhythmia. Patients with a history of prolonged QT interval or those at risk for it should be closely monitored.

Adult dose for nausea and/or vomiting
4 to 8mg PO or IV.

• Repeat every 4-8 hours if necessary.

• A maximum cumulative daily dose of 24mg may be a conservative approach for ensuring safety.

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Executive Summary
Phentolamine is a vasodilator used to prevent tissue necrosis caused by extravasated catecholamine infusions (epinephrine, norepinephrine, dopamine, etc). Available in the US. Limited stock in Canada. Unavailable in Chile. 

Adult dose for vasopressor extravasation:
5-10 mg diluted in 10-20 ml of NaCl 0.9% subcutaneous immediately after extravasation (use within 12 hours). 

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(August 31 2023)

Propofol is a hypnotic agent that enhances the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) in the brain through NMDA and GABA-A receptors, resulting in sedation and unconsciousness. It is the third most commonly used induction agent in the ED, following etomidate and ketamine. 

• It has a  fast onset of action and an extremely short half-life, which makes it suitable for various situations in the ED, particularly for patients requiring short-term sedation (3). It may be considered a first-line induction agent for status epilepticus.

⚠ Cautions summary: 

• Circulatory, CNS and respiratory depression: reduction in blood pressure due to vasodilation and direct myocardial depression mandates extremely cautious use in unstable patients. Etomidate or ketamine are often preferred for hemodynamically unstable patients. High risk medication that should be used with extreme caution, especially when other CNS depressants are used concomitantly. 

• Allergies: the manufacturer’s label contraindicates propofol in patients allergic to soybean or eggs. This concern has been discredited by multiple studies, experts, and societies in the fields of anesthesia, emergency medicine and immunology.

• PRIS (Propofol-Related Infusion Syndrome): propofol is formulated in an oil-in-water emulsion that can potentially lead to PRIS –characterized by acidosis, rhabdomyolysis, refractory bradycardia and eventually organ failures and death–. Prolonged and high-dose infusions pose a major risk.

Adult dose for rapid sequence intubation (RSI) (25)

1.5 mg/kg IV bolus.

• Consider a reduced dose (0.5-1 mg/kg) in hemodynamically unstable or elderly patients. Other inductors agents may be more appropriate (eg. etomidate or ketamine).

• Onset of action: 15-45 sec.

• Duration of effect: 5-10 min.

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Executive Summary
Rabies is a zoonotic disease positioned as one of the most lethal viral infections; mortality approaches 100%. It is also preventable in nearly 100% of expositions when vaccination has been properly administered. 

Adult and pediatric vaccination regimen for post-exposure prophylaxis (PEP)

• Immunocompetent without prior rabies immunization:
  4 doses IM, days 0-3-7 and 14*

• Immunocompromised without prior rabies immunization:
  5 doses IM, days 0-3-7-14 and 28

• Prior rabies immunization**:
  2 doses IM, days 0 and 3

*Some regions and their local guidelines still  recommend a universal 5-dose regimen for PEP as previously was recommended by the US-CDC, and currently some manufacturers. 

**Complete 4 doses of PEP scheme or 3 doses of PrEP (pre-exposure prophylaxis).

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Executive Summary

Rocuronium is becoming the most commonly used non-depolarizing neuromuscular blocking agent (N-NMBA) in the emergency department due to its ability to create excellent intubating conditions compared to other NMBAs, and its superior safety profile over succinylcholine for a variety of clinical conditions when the latter is contraindicated (NMBA table). 

• Studies have shown that there are no significant differences in intubation conditions when using rocuronium at a dose ≥1.2 mg/kg compared to succinylcholine 1.5 mg/kg for RSI.

• Non-depolarizing NMBAs can be reversed with sugammadex at any point, or with neostigmine when significant recovery has been achieved (40% approx). 

  • In the ED, NMBA reversal is not an option in the vast majority of cases and is not included in most Emergency Medicine difficult airway algorithms. 

• ⚠ The only contraindication is a prior anaphylaxis to rocuronium.

Adult dose for rapid sequence intubation

1.5mg/kg IV

• Time to intubation level paralysis: 60 sec

• Duration of paralysis: 40-60 min

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Executive Summary

Acute Myocardial Infarction with ST elevation (STEMI <12hrs)

FDA approved, 2000. Indicated when anticipated STEMI diagnosis to Percutaneous Coronary Intervention-mediated reperfusion time is >120min. 

Adult dose (IV ,bolus):

• <60 kg 30mg 

• 60 - 69 kg 35mg

• 70 - 79 kg 40mg

• 80 - 89 kg 45mg

• ≥90 kg 50mg

Acute Ischemic Stroke (AIS <4.5hrs)

Not FDA approved. 

Adult dose (IV ,bolus):

• AIS eligible for mechanical thrombectomy

  • 0.25mg/kg bolus (max 25mg)

• AIS with minor neurological impairment uneligible for a mechanical thrombectomy

  • Under revision due to NOR-TEST 2 trial results (2022)

Pulmonary Embolism (PE)

Not FDA approved. Prefer alteplase for PE fibrinolytic therapy. If unavailable, consider tenecteplase.

Adult dose (IV, bolus):

• <60 kg 30mg

• 60 - 69 kg 35mg

• 70 - 79 kg 40mg

• 80 - 89 kg 45mg

• ≥90 kg 50mg

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Executive Summary
Tetanus Immune Globulin (TIG) is indicated for tetanus disease treatment and prophylaxis (the latter in individuals without updated or an  unknown tetanus immunization who have suffered a contaminated or a  tetanus-prone wound).

Adult dose for tetanus treatment and prophylaxis

• Tetanus treatment
  500 units IM with part of the dose infiltrated close to the source wound. 

  • Up to 6000 units can be used. 

• Tetanus prophylaxis:
  250 units IM (single dose).

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Executive Summary
Thiamine (vitamin B1) is a water-soluble vitamin that is essential in the creation and utilization of cellular energy  related to aerobic glycolysis in the citric acid cycle. Its deficiency leads to cardiovascular (heart failure) and neurologic disease (Wernicke - Korsakoff syndrome, "WK"). In the ED thiamine is frequently indicated in the prevention and treatment of WK, mainly in patients with ethanol dependence and/or malnutrition. 

Adult dose for WK prevention and treatment

• WK prevention

  • 100-250mg IV daily for 3-5 days, then consider daily PO supplementation

• WK treatment

  • 500mg IV every 8 hours for 3-5 days, then 250mg IV daily for 3-5 days, then indefinitely daily PO supplementation 

  • Always supplement with magnesium (2gr MgSO4 daily)

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Executive Summary

The antifibrinolytic agent tranexamic acid (TXA) is a synthetic lysin derivative that binds plasminogen and plasmin, blocking their interaction with fibrin. It is indicated extensively in the ED for a variety of bleeding scenarios. 

• The most validated usage is in patients with acute trauma with a suspected severe hemorrhage. Currently it is an established component of “damage control resuscitation”. 

• All-cause mortality reduction was proven by the game-changer CRASH-2 trial –a strong double-blind RCT that compared TXA versus a placebo in trauma, based on the uncertainty principle (attending physician not being sure if TXA was beneficial or not)–. Afterwards other studies have documented improved survival rates.

Adult dose for trauma with risk of significant hemorrhage

1gr in 10 min IV + 1gr in 8 hrs IV.

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• ISMP - Institute for Safe Medication Practices
  https://www.ismp.org/ 

• WHO - World Health Organization Model List of Essential Medicines 2021
  https://www.who.int/(...) 

• US FDA - Approved Drugs Orange Book 2023
  https://www.fda.gov/(...)

• EMA - European Medicines Agency - Medicines Information
  https://www.ema.europa.eu/(...)

• ACEP - American College of Emergency Physicians - Clinical Policies
  https://www.acep.org/(...)

• AAEM - American Academy of Emergency Medicine - Clinical Practice Statements
  https://www.aaem.org/(...)

• CAEP - Canadian Association of Emergency Physicians - Clinical Practice Guidelines
  https://caep.ca/(...)

• EUSEM - European Society for Emergency Medicine - Guidelines for the management of acute pain in emergency situations 2020
  https://eusem.org/(...)

• RCEM - The Royal College of Emergency Medicine - Clinical Guidance
  https://www.rcem.ac.uk/(...)

• ASHP - American Society of Health-System Pharmacists - Guidelines on Emergency Medicine Pharmacist Services
  https://www.ashp.org/(...)