Applied Pharmacology — Vasoactives, Sedatives and Paralysers

Also known as Vasoactive drugs · Inotropes · Vasopressors · Pharmacokinetics · Pharmacodynamics · Drug interactions · Receptor pharmacology

The applied pharmacology of the ICU drugs — the vasoactives (the noradrenaline, the vasopressin, the dobutamine, the milrinone, the adrenaline), the sedatives (the propofol, the midazolam, the dexmedetomidine, the ketamine), the analgesics (the fentanyl, the morphine), the paralysers (the rocuronium, the cisatracurium) — with their receptor pharmacology, the PK/PD, the doses, the adverse effects, and the evidence for the choice in each clinical scenario.

high29 referencesUpdated 18 Aug 202633 min readSource-verified · Sept 2026

Checked against its sources on 3 Sept 2026

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16 MCQs

The one-line answer

Noradrenaline is the first-line vasopressor for every shock type — SOAP II found no 28-day mortality difference with dopamine but significantly more arrhythmic events (24.1% vs 12.4%), so dopamine is retired except for bradycardic shock. Vasopressin is a low-dose adjunct in septic shock — VASST compared 0.01-0.03 U/min against norepinephrine with no mortality benefit and no excess of serious adverse events; VANISH titrated up to 0.06 U/min without improving kidney-failure-free days. For sedation, the evidence favours non-benzodiazepine infusions — MENDS gave dexmedetomidine more days alive without delirium or coma than lorazepam (7 vs 3), and SPICE III found early dexmedetomidine gave a 90-day mortality rate identical to usual care (29.1% vs 29.1%) with more bradycardia. For antibiotics, critical illness shifts fluid balance, albumin, and organ function, so individualise the dose: load in full, then reason from hydrophilic versus lipophilic, ARC versus CRRT, and time-above-MIC versus AUC.^[1]^[2]^[3]^[4]^[5]^[23]

Meet the patient

A 68-year-old with pneumonia and septic shock has had his crystalloid boluses. His MAP is 58, lactate 4.2, oliguric — and now he is in new atrial fibrillation at 140 a minute. The registrar asks which vasoactive to start, and at what dose.^[1]

The two questions that decide his next hour are the two that decide every ICU drug choice: which receptor matches this phenotype? and what has his physiology done to the dose? Hold those two questions and the four classes below line up neatly.^[1]

References29Show

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