What are the commonly used drugs and dosages for intravenous (IV) sedation?

Commonly Used Drugs for Intravenous Sedation

The most commonly used drugs for IV sedation are midazolam, propofol, lorazepam, and etomidate, with midazolam and propofol being the dominant agents in current practice. 1

Primary Sedative Agents

Midazolam (Most Common Benzodiazepine)

Midazolam is the most frequently used benzodiazepine for IV sedation due to its rapid onset and short duration. 2

Dosing for Procedural Sedation:

• Adults <55 years: Initial dose 0.5-2.5 mg IV over 2-3 minutes; titrate in 1 mg increments every 2+ minutes to effect (maximum typically 3.5 mg for conscious sedation) 3
• Adults ≥55 years or debilitated: Reduce initial dose by 20% or more; start with 1-1.5 mg IV 4, 3
• Pediatric 6 months-5 years: 0.05-0.1 mg/kg IV (maximum typically 6 mg) 3
• Pediatric 6-12 years: 0.025-0.05 mg/kg IV (maximum typically 10 mg) 3
• Pediatric 12-16 years: Dose as adults 3

Continuous Infusion:

• Adults: Loading dose 0.01-0.05 mg/kg, then 0.02-0.1 mg/kg/hr (1-7 mg/hr) 3
• Pediatric: Loading dose 0.05-0.2 mg/kg over 2-3 minutes, then 0.06-0.12 mg/kg/hr 3
• Neonates <32 weeks: 0.03 mg/kg/hr (no loading dose) 3
• Neonates >32 weeks: 0.06 mg/kg/hr (no loading dose) 3

Key Safety Points:

• Critical: Administer over 2-3 minutes minimum; wait an additional 2-3 minutes between doses to evaluate effect 3
• Respiratory depression risk increases significantly when combined with opioids—reduce both doses by at least 50% 3, 2
• Monitor oxygen saturation continuously 4
• Have flumazenil immediately available for reversal 2

Propofol (Preferred for Short Procedures)

Propofol provides more rapid onset (1-2 minutes) and faster recovery than midazolam, making it increasingly preferred despite requiring deeper sedation monitoring. 1, 5

Dosing:

• Adults: Loading dose 5 μg/kg/min over 5 minutes (avoid in hemodynamically unstable patients), then 5-50 μg/kg/min continuous infusion 1
• Pediatric: 0.5-1 mg/kg IV followed by titration 5

Advantages Over Midazolam:

• Shorter recovery time (median 36 minutes vs 52 minutes for midazolam) 5
• Less nursing monitoring time required 5
• Higher physician satisfaction scores 5

Critical Warnings:

• Causes hypotension and respiratory depression 1
• Risk of propofol-related infusion syndrome with prolonged high-dose use 1
• Pain on injection through peripheral veins 1
• Requires monitoring capability for deep sedation 6

Lorazepam (For Longer Procedures)

Lorazepam has a longer duration of action (1-24 hours) compared to midazolam (1-4 hours), making it suitable for prolonged sedation but less ideal for brief procedures. 4

Dosing:

• Adults: 0.02-0.04 mg/kg IV loading dose (maximum 2 mg), then 0.02-0.06 mg/kg every 2-6 hours PRN or 0.01-0.1 mg/kg/hr continuous infusion (maximum 10 mg/hr) 1
• Pediatric seizures: 0.05-0.1 mg/kg IV/IM (maximum 4 mg per dose), may repeat every 10-15 minutes 1

Safety Considerations:

• Reduce dose by 20% or more in elderly patients due to reduced clearance 4
• Risk of propylene glycol toxicity with prolonged infusion 1
• Increased apnea risk when combined with other sedatives 1, 4
• Onset slower than midazolam (15-20 minutes) 1

Etomidate (For Rapid Sequence Intubation)

Etomidate is the preferred sedative for RSI in hemodynamically unstable patients because it does not lower blood pressure and reduces intracranial pressure. 1, 7

Dosing:

• Pediatric and Adult: 0.2-0.4 mg/kg IV/IO bolus (maximum 20 mg) 1, 7

Advantages:

• Rapid onset with 10-15 minute duration 1
• Maintains blood pressure—ideal for trauma, head injury, or hypotension 7
• Lowers intracranial pressure 7

Limitations:

• No analgesic properties 1
• May cause brief myoclonic activity (hiccups, cough, twitching) 1, 7
• Causes transient adrenal suppression (not clinically significant for single dose) 7

Alternative Agents

Dexmedetomidine (Emerging Role)

Dexmedetomidine is increasingly used for sedation requiring less frequent dose adjustments compared to midazolam. 8

Dosing:

• Adults: Loading dose 1 μg/kg IV over 10 minutes (avoid in hemodynamically unstable patients), then 0.2-0.7 μg/kg/hr maintenance infusion (may increase to 1.5 μg/kg/hr) 1

Advantages:

• Required fewer dosing adjustments than midazolam in comparative studies 8
• Maintains respiratory drive better than benzodiazepines 6

Warnings:

• Bradycardia and hypotension common 1
• Hypertension can occur with loading dose 1
• Longer onset (5-10 minutes) 1

Ketamine (For Painful Procedures)

Ketamine provides both sedation and analgesia, making it particularly useful for painful procedures in pediatrics. 1

Dosing:

• Pediatric IV: 1.5 mg/kg with atropine 0.01 mg/kg (minimum 0.1 mg, maximum 0.5 mg) 1
• Pediatric IM: 4 mg/kg initial dose, may repeat 2-4 mg/kg in 5-10 minutes 1

Key Points:

• Does not cause respiratory depression like benzodiazepines 1
• Recovery agitation more common in younger children and higher ASA status 1
• Emesis increases with age 1
• Adding midazolam 0.05 mg/kg does not reduce recovery agitation 1

Critical Safety Principles Across All Agents

Universal Monitoring Requirements:

• Continuous oxygen saturation monitoring mandatory 4, 2
• Respiratory rate and effort assessment 4
• Be prepared to provide ventilatory support 4, 3
• Titrate slowly to effect—never rush administration 3

Common Pitfalls to Avoid:

• Failure to wait adequate time between doses (2-3 minutes for midazolam) leads to oversedation 3
• Combining sedatives with opioids without dose reduction—reduce each by at least 50% 3, 2
• Rapid IV administration precipitates respiratory depression and hypotension 1
• Inadequate monitoring in elderly or debilitated patients who require 20%+ dose reduction 4, 3

Reversal Agents:

• Flumazenil for benzodiazepines: 0.01-0.02 mg/kg IV (maximum 0.2 mg), repeat at 1-minute intervals to maximum cumulative dose of 0.05 mg/kg or 1 mg 7
• Warning: Flumazenil reverses anticonvulsant effects and may precipitate seizures or withdrawal in benzodiazepine-dependent patients 1, 7