SURGERY: Cross topic pharmacology

Antibiotics

Drug class: Medicines used to treat susceptible bacterial infections. | Uses: Treatment of bacterial infection and selected surgical prophylaxis. | Side effects: Allergy, gastrointestinal upset, antibiotic-associated diarrhoea and agent-specific toxicity. | Contraindications: Depend on the antibiotic and allergy history. | Important cautions: Choose according to infection site, likely organisms, cultures, renal function and local antimicrobial policy; review duration.

Laxatives

Drug class: Bulk-forming, osmotic, stimulant and stool-softening medicines. | Uses: Constipation and selected bowel preparation regimens. | Side effects: Cramps, bloating, diarrhoea, dehydration and electrolyte disturbances. | Contraindications: Suspected obstruction, ileus or acute unexplained abdominal pain require assessment. | Important cautions: Select the type according to symptoms and clinical context; persistent constipation or red flags need investigation.

Proton pump inhibitors

Drug class: Gastric acid suppressants that inhibit the H+/K+ ATPase proton pump. | Uses: Reflux disease, peptic ulcer disease and selected gastroprotection. | Side effects: Headache, gastrointestinal upset and, with prolonged use, possible hypomagnesaemia or vitamin B12 deficiency. | Contraindications: Depend on agent and product-specific restrictions. | Important cautions: Review ongoing indication, duration and interactions, particularly omeprazole/esomeprazole with clopidogrel.

Antiemetics

Drug class: Medicines acting on serotonin, dopamine, histamine or muscarinic pathways. | Uses: Prevention and treatment of nausea and vomiting. | Side effects: Depend on agent and may include QT prolongation, sedation, anticholinergic effects or extrapyramidal reactions. | Contraindications: Depend on agent; consider obstruction, Parkinson disease, prolonged QT, glaucoma and urinary retention where relevant. | Important cautions: Select according to cause and patient comorbidities; review sedation, ECG risk and interactions.

Anticoagulants

Drug class: Medicines that inhibit coagulation, including heparins, vitamin K antagonists and DOACs. | Uses: Treatment and prevention of VTE and prevention of embolic stroke in appropriate patients. | Side effects: Bleeding, anaemia and agent-specific adverse effects such as HIT. | Contraindications: Active major bleeding and agent-specific conditions. | Important cautions: Check renal function, indication, dose, interactions and bleeding risk. Perioperative interruption and reversal depend on the agent and patient.

NSAIDs

Drug class: Cyclo-oxygenase inhibitors with analgesic and anti-inflammatory effects. | Uses: Pain and inflammatory conditions. | Side effects: GI ulceration/bleeding, renal impairment, fluid retention, hypertension and cardiovascular events. | Contraindications: Depend on the agent and include important GI, renal, cardiac and hypersensitivity restrictions. | Important cautions: Use the lowest effective dose for the shortest duration; avoid duplicate NSAIDs and assess pregnancy and anticoagulant use.

Local anaesthetics

Drug class: Usually sodium-channel blockers that prevent nerve impulse conduction. | Uses: Local infiltration, nerve blocks and regional anaesthesia. | Side effects: Local irritation; systemic toxicity can cause seizures, arrhythmias and cardiovascular collapse. | Contraindications: Depend on agent, route, site and formulation. | Important cautions: Calculate appropriate dosing, prevent intravascular injection and know the local anaesthetic systemic toxicity protocol.

Muscle relaxants

Drug class: Neuromuscular blocking agents, including depolarising suxamethonium and non-depolarising atracurium. | Uses: Facilitate intubation, surgery and selected mechanical ventilation. | Side effects: Apnoea, prolonged paralysis, haemodynamic effects and agent-specific risks. | Contraindications: Depend on agent; malignant hyperthermia susceptibility and hyperkalaemia risk are particularly important for suxamethonium. | Important cautions: These agents do not cause unconsciousness or analgesia; ensure anaesthesia, ventilation and neuromuscular monitoring.

Intravenous anaesthetic agents

Drug class: Intravenous hypnotics such as propofol. | Uses: Induction/maintenance of anaesthesia or selected procedural sedation. | Side effects: Respiratory depression, apnoea and hypotension. | Contraindications: Depend on the agent and formulation. | Important cautions: Require appropriate monitoring and staff able to support airway and circulation.

Inhalational anaesthetic agents

Drug class: Volatile general anaesthetics such as sevoflurane. | Uses: Induction or maintenance of general anaesthesia. | Side effects: Respiratory depression, hypotension, postoperative nausea/vomiting and malignant hyperthermia risk with susceptible agents. | Contraindications: Malignant hyperthermia susceptibility is a key restriction for volatile agents. | Important cautions: Require trained anaesthetic supervision and monitoring.

Resuscitation medicines

Drug class: Emergency medicines including adrenaline and amiodarone. | Uses: Protocol-defined management of cardiac arrest and selected arrhythmias. | Side effects: Arrhythmias, blood-pressure changes and ischaemic effects. | Contraindications: In life-threatening emergencies, use depends on the resuscitation algorithm and clinical context. | Important cautions: Follow the current Resuscitation Council UK algorithm for route, concentration, timing and indication.

Cardiovascular drugs in ICU

Drug class: Vasoactive medicines such as adrenaline, noradrenaline and vasopressin. | Uses: Selected shock states and haemodynamic instability. | Side effects: Arrhythmias, vasoconstriction, ischaemia and blood-pressure disturbances. | Contraindications: Agent- and situation-specific. | Important cautions: Require specialist titration and close haemodynamic monitoring; assess tissue perfusion and reversible causes.