SURGERY: RESUS, CARDIOVASC, ICU PHARMACOLOGY

Adrenaline (epinephrine)

Drug class: Alpha- and beta-adrenergic agonist. | Uses: Cardiac arrest, anaphylaxis and selected severe hypotensive states. | Side effects: Tachycardia, arrhythmias, hypertension, myocardial ischaemia and tremor. | Contraindications: In life-threatening emergencies, indicated use generally takes priority; non-emergency use requires individual assessment. | Important cautions: Route and concentration errors can be fatal. Follow the appropriate UK resuscitation or anaphylaxis protocol.

Amiodarone

Drug class: Class III antiarrhythmic with additional electrophysiological effects. | Uses: Selected tachyarrhythmias and shock-refractory ventricular fibrillation/pulseless ventricular tachycardia under resuscitation protocols. | Side effects: Bradycardia, hypotension, QT prolongation, thyroid dysfunction, liver toxicity and pulmonary toxicity. | Contraindications: Depend on indication and route; check conduction disease, bradycardia and thyroid-related restrictions. | Important cautions: Review ECG, electrolytes, thyroid and liver function for ongoing treatment; interactions include warfarin and digoxin.

Noradrenaline (norepinephrine)

Drug class: Predominantly alpha-adrenergic vasopressor with beta-1 activity. | Uses: Severe hypotension and vasodilatory shock in critical care. | Side effects: Hypertension, arrhythmias, peripheral or visceral ischaemia and tissue necrosis after extravasation. | Contraindications: Depend on clinical context; check product-specific restrictions. | Important cautions: Requires close haemodynamic monitoring, infusion-site checks and appropriate management of hypovolaemia.

Vasopressin

Drug class: Vasopressor acting at V1 receptors with antidiuretic effects via V2 receptors. | Uses: Selected vasodilatory shock states as an adjunct to other vasopressors. | Side effects: Peripheral or visceral ischaemia, reduced cardiac output and hyponatraemia. | Contraindications: Depend on indication and formulation. | Important cautions: Use with critical-care monitoring; assess perfusion and sodium/water balance.

Clonidine

Drug class: Central alpha-2 adrenergic agonist; sympatholytic. | Uses: Selected hypertension indications and specialist-directed uses. | Side effects: Sedation, dry mouth, dizziness, bradycardia and hypotension. | Contraindications: Depend on formulation and indication; check significant bradyarrhythmia-related restrictions. | Important cautions: Abrupt withdrawal can cause rebound hypertension; monitor sedation and interactions with opioids.