ICU Nursing - Pharmacology - Drug Reference 2026
ICU Medications Nurses Must Know 2026
Critical care pharmacology separates competent ICU nurses from exceptional ones. This reference covers the drug classes you manage daily — mechanisms, titration ranges, key monitoring parameters, and the pearls that prevent errors.
This article was created with AI assistance.
Clinical disclaimer: Always follow your facility's protocols, physician orders, and pharmacist guidance. Dosing ranges here reflect general clinical practice — your institution's guidelines take precedence.
Vasopressors
Norepinephrine (Levophed)
| Parameter | Detail |
|---|
| Mechanism | Alpha-1 (vasoconstriction) + Beta-1 (inotropy); increases SVR and MAP |
| Indication | Septic shock, distributive shock, vasodilatory states — first-line vasopressor in sepsis |
| Dose range | 0.01 - 3 mcg/kg/min (some protocols go higher) |
| Titrate to | MAP 65+ mmHg (or per orders) |
| Key monitoring | MAP, HR, extremity perfusion, IV site (vesicant — use central line) |
| Nursing pearl | Extravasation causes tissue necrosis; central access strongly preferred. If peripheral only, monitor site every hour minimum. Phentolamine antidote for extravasation. |
Vasopressin
| Parameter | Detail |
|---|
| Mechanism | V1 receptor agonist — direct vasoconstriction without adrenergic mechanism; also antidiuretic (ADH) |
| Indication | Add-on vasopressor in septic shock refractory to norepinephrine; vasodilatory shock; variceal hemorrhage |
| Dose | 0.03-0.04 units/min (fixed dose — NOT titrated in septic shock per Surviving Sepsis guidelines) |
| Key monitoring | MAP, UO (antidiuretic effect can cause fluid retention), mesenteric ischemia signs |
| Nursing pearl | Not titrated in most protocols — it is added at 0.03-0.04 units/min and stays there while norepinephrine is titrated around it. Can cause profound mesenteric ischemia at high doses. |
Phenylephrine
| Parameter | Detail |
|---|
| Mechanism | Pure alpha-1 agonist — vasoconstriction only, no inotropy |
| Indication | Hypotension with tachycardia (avoids the HR increase of norepi); neurogenic shock; intraoperative hypotension |
| Dose range | 0.5 - 5 mcg/kg/min |
| Key monitoring | MAP, HR — reflex bradycardia can occur; contraindicated in cardiogenic shock (increases afterload) |
| Nursing pearl | Do NOT use in cardiogenic shock — pure vasoconstriction increases afterload and worsens cardiac output in an already-failing heart. |
Sedation and Analgesia
Propofol
| Parameter | Detail |
|---|
| Mechanism | GABA-A potentiation; rapid onset/offset |
| Indication | Sedation in mechanically ventilated patients; procedural sedation |
| Dose range | 5 - 50 mcg/kg/min (titrate to RASS target) |
| Key monitoring | RASS score, triglycerides (q48-72h on prolonged infusions), BP (significant vasodilator), signs of propofol infusion syndrome |
| Propofol Infusion Syndrome (PRIS) | Rare but fatal: metabolic acidosis, rhabdomyolysis, cardiac arrhythmias, renal failure. Risk with doses greater than 83 mcg/kg/min for greater than 48 hours. Monitor triglycerides, CK, and ECG on prolonged high-dose infusions. |
| Nursing pearl | Contains soybean oil and egg phospholipid — consider allergies. Strict aseptic technique — propofol is a bacterial growth medium. Discard vials within 12 hours of opening. |
Dexmedetomidine (Precedex)
| Parameter | Detail |
|---|
| Mechanism | Alpha-2 agonist — sedation, analgesia, anxiolysis without respiratory depression |
| Indication | Light sedation in vented patients; agitated delirium; alcohol withdrawal adjunct; allows awakening trials without full wean |
| Dose range | 0.2 - 1.5 mcg/kg/hr (loading dose optional and controversial) |
| Key monitoring | HR (bradycardia common), BP (biphasic — initial hypertension then hypotension), respiratory rate (less suppression than opioids/benzos) |
| Nursing pearl | Patients on dex are often rousable and interactive — this is normal and is the goal. Does not cover pain independently — combine with fentanyl for analgesia. Very expensive; ensure indication is justified. |
Paralytics (Neuromuscular Blocking Agents)
Rocuronium
| Parameter | Detail |
|---|
| Mechanism | Non-depolarizing NMBA — blocks acetylcholine at neuromuscular junction |
| Indication | RSI (rapid sequence intubation), facilitation of mechanical ventilation, refractory ARDS |
| RSI dose | 1.2 mg/kg IV push (high-dose for RSI; onset ~60 seconds) |
| Reversal | Sugammadex (Bridion) — binds and inactivates rocuronium |
| Critical nursing rule | NEVER paralyze a patient who is not adequately sedated and analgesed. A paralyzed, awake patient experiences profound terror and pain with no ability to communicate. Always confirm deep sedation (RASS -4 to -5) before paralytic infusion. |
| Monitoring | Train-of-four (TOF) monitoring for continuous infusions; target 1-2 twitches out of 4 |
Anticoagulation
Unfractionated Heparin (UFH)
| Parameter | Detail |
|---|
| Indication | DVT treatment/prophylaxis, ACS, PE, CRRT anticoagulation, bridging |
| Therapeutic monitoring | aPTT (target typically 60-100 seconds) or anti-Xa (target 0.3-0.7 units/mL for therapeutic dosing) |
| Reversal | Protamine sulfate (1 mg per 100 units heparin administered in last 4 hours) |
| HIT (Heparin-Induced Thrombocytopenia) | Platelet drop greater than 50% from baseline OR below 100K after 5-10 days of heparin exposure. Paradoxically THROMBOTIC — do NOT stop anticoagulation; switch to direct thrombin inhibitor (argatroban). Order HIT antibody panel and 4Ts score. |
Cardiac Medications
| Drug | Class | Key Use | Nursing Note |
|---|
| Dobutamine | Inotrope (Beta-1) | Cardiogenic shock, low CO/CI | Increases HR and inotropy; can worsen ischemia; watch for tachyarrhythmias |
| Milrinone | PDE-3 inhibitor | Heart failure, pulmonary hypertension | Vasodilates as well as increases inotropy; dangerous in RV failure and hypovolemia — can crash BP |
| Amiodarone | Class III antiarrhythmic | Afib, VT, VF | Pulmonary toxicity with long-term use; thyroid effects; phlebitis with peripheral IV (use central); half-life up to 40-55 days |
| Lidocaine | Class IB antiarrhythmic | Ventricular arrhythmias | CNS toxicity (seizures, altered mental status) at toxic levels; monitor for AMS |
| Adenosine | Endogenous nucleoside | SVT termination | Must give rapid IV push followed immediately by saline flush; causes transient asystole (warn the patient); half-life less than 10 seconds |
This reference is for educational purposes only. Always verify orders with your pharmacist, follow facility protocols, and use current references for
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