Emergency Drugs Collection

🧲 Activated charcoal

• MOA: Adsorbs many toxins in GI tract → reduces absorption (best early).
• Dose (PO): 50 g PO adult (timing depends on toxin; commonly within ~1–2 hours, but may be later for modified-release or anticholinergic slow gastric emptying).
• Dose (IV): N/A
• Indication: Selected recent ingestions of adsorbable drugs (NPIS/local guidance).
• Not useful for: Alcohols, acids/alkalis, metals (iron, lithium), most solvents.
• Key practical: Consider airway protection if reduced GCS; give with antiemetic only if safe.
• Caution: Aspiration risk (major); bowel obstruction/ileus; avoid if corrosive ingestion or high aspiration risk without protected airway.

🧪 Acetylcysteine (NAC)

• MOA: Replenishes glutathione → detoxifies NAPQI; improves microcirculation and may be beneficial in established liver injury.
• Dose (IV): 150 mg/kg (1 h) → 50 mg/kg (4 h) → 100 mg/kg (16 h) (21 h regimen). Extend/continue if ALT/INR/paracetamol remain abnormal.
• Dose (PO): 140 mg/kg load → 70 mg/kg every 4 h × 17 doses (72 h total).
• Indication: Paracetamol overdose (nomogram-guided, staggered ingestion, or high-risk features). Also used in some non-paracetamol acute liver failure (specialist).
• Monitoring: Paracetamol level(s), ALT/AST, INR, creatinine, pH/lactate, glucose; repeat at end of regimen to decide on extension.
• Timing pearl: Greatest benefit early, but still treat late presenters if evidence of liver injury or significant risk.
• Caution: Anaphylactoid reactions (flushing, wheeze, hypotension) → pause/slow infusion, antihistamine if needed; fluid volume may need adjustment in HF/CKD (protocol-led).

🫀 Adenosine

• MOA: A1 receptor activation → transient AV nodal block (very short half-life).
• Dose (IV): 6 mg rapid push → 12 mg after 1–2 min (may repeat 12 mg once). Give via large-bore cannula with immediate flush.
• Dose (PO): N/A
• Indication: Stable regular narrow-complex SVT; diagnostic for regular monomorphic wide-complex tachy if stable and regular (specialist/Resus Council style protocols).
• Onset/duration: Seconds; expected brief AV block/asystole.
• ECG pearl: Do not use for irregular wide-complex tachycardia (e.g., AF with WPW) → risk VF.
• Interactions: Dipyridamole potentiates (reduce dose); methylxanthines/caffeine antagonise (may need higher dose); transplanted heart is very sensitive (lower dose).
• Caution: Bronchospasm in asthma/COPD; high-grade AV block/sick sinus without pacing; warn patient about chest tightness/flushing.

🚑 Adrenaline (Epinephrine)

• MOA: α1 vasoconstriction (↑ SVR), β1 inotropy/chronotropy (↑ CO), β2 bronchodilation + mast cell stabilisation.
• Dose (IM/IV): Arrest: 1 mg (1:10,000) IV q3–5 min (ALS). Anaphylaxis: 0.5 mg IM (1:1,000) adults (anterolateral thigh) and repeat as needed per protocol. Infusions are protocol-led (critical care).
• Dose (PO): N/A
• Indication: Cardiac arrest; anaphylaxis; refractory shock/hypotension (specialist infusion).
• Monitoring: Continuous ECG, BP, SpO2; consider arterial line for infusion; lactate/perfusion endpoints in shock.
• Practical pearls: Concentration errors are common—separate “IM 1:1,000” from “IV 1:10,000” mentally and physically.
• Extravasation: Risk of local ischaemia—central line preferred for infusions; manage per local extravasation protocol.
• Caution: Arrhythmias, myocardial ischaemia (especially older patients); hypertension/tremor/anxiety; use correctly in pregnancy when indicated (maternal resus takes priority).

🩸 Anti-D (Rho(D) immune globulin)

• MOA: Passive anti-D antibodies clear fetal RhD-positive red cells → prevents maternal sensitisation.
• Dose (IM): Protocol-led (often 500 IU IM within 72 h postpartum or sensitising event; adjust if large fetomaternal haemorrhage per Kleihauer).
• Dose (PO/IV): N/A
• Indication: RhD-negative mother after potential exposure to RhD-positive fetal blood (delivery, APH, procedures, trauma, etc.).
• Key practical: Ensure maternal group/antibody screen; check baby’s RhD where relevant; consider FMH quantification for dosing.
• Caution: Not for RhD-positive mother or already-sensitised mothers (manage via fetal medicine); hypersensitivity rare.

🫀 Amiodarone

• MOA: Predominantly Class III (K+ channel block → prolongs repolarisation); also Na+ block, β-blocking, Ca2+ block effects.
• Dose (IV): VF/VT arrest: 300 mg IV, then 150 mg if refractory. Stable VT: 150 mg over 10 min then infusion per protocol.
• Dose (PO): Not for acute emergency dosing here (chronic regimens are specialist).
• Indication: VF/VT; stable monomorphic VT; some atrial arrhythmias where rate control fails (specialist).
• Monitoring: ECG/QT, BP during infusion; watch for bradycardia and hypotension (solvent-related).
• Interactions: Potentiates warfarin (↑ INR) and digoxin; CYP interactions—check before discharge.
• Caution: Bradycardia, hypotension; chronic toxicity (thyroid, lung fibrosis, hepatitis, corneal deposits). Avoid combining with other QT-prolongers if possible.

🧬 Apixaban

• MOA: Direct factor Xa inhibitor → reduces thrombin generation.
• Dose (PO): AF: 5 mg BD (dose reduction criteria per BNF). VTE: 10 mg BD ×7 days then 5 mg BD.
• Dose (IV): N/A
• Indication: Stroke prevention in non-valvular AF; treatment/secondary prevention of VTE.
• Monitoring: No routine INR; check baseline and periodic renal function, LFTs, haemoglobin; adherence is critical due to short half-life.
• Peri-procedure: Holding intervals depend on renal function and bleeding risk—follow local peri-op anticoag guidance.
• Caution: Bleeding; severe hepatic impairment; interactions with strong CYP3A4/P-gp inhibitors/inducers; generally avoid in pregnancy unless specialist.

🫀 Atropine

• MOA: Antimuscarinic → decreases parasympathetic tone to SA/AV node; dries secretions.
• Dose (IV): Adult bradycardia: 0.5 mg q3–5 min (max 3 mg). OP poisoning: 1–6 mg q3–5 min until secretions/bronchospasm controlled (large cumulative doses may be needed).
• Dose (PO): N/A
• Indication: Symptomatic bradycardia (ALS); organophosphate/carbamate poisoning.
• Bradycardia pearl: Often ineffective in high-grade infranodal block—prepare pacing.
• OP pearl: Titrate to endpoints (“dry chest”, HR, BP, oxygenation) rather than fixed total dose.
• Caution: Tachyarrhythmias, ischaemia; hyperthermia/urinary retention; transplanted hearts may respond unpredictably.

⚡ Calcium gluconate / calcium chloride

• MOA: Stabilises myocardial membrane; counters hyperkalaemia ECG toxicity; supports contractility in CCB overdose.
• Dose (IV): Calcium gluconate 10 mL of 10% IV; repeat if ECG changes persist. Calcium chloride is more concentrated (central line preferred).
• Dose (PO): N/A
• Indication: Hyperkalaemia with ECG changes; symptomatic hypocalcaemia; calcium channel blocker overdose.
• Monitoring: ECG response is the endpoint (peaked T waves/QRS widening); check potassium and calcium; consider repeat dosing in ongoing ECG toxicity.
• Practical: Use a patent cannula; flush well; avoid mixing in same line with bicarbonate (precipitation risk).
• Caution: Extravasation (especially CaCl); caution in digoxin toxicity (specialist advice—risk of arrhythmias); hypercalcaemia if repeated without monitoring.

🩸 Carboprost (Hemabate)

• MOA: Prostaglandin F2α analogue → strong uterine contraction and reduced bleeding.
• Dose (IM): 250 microg IM, repeat every 15–90 min (max 2 mg) per protocol.
• Dose (PO/IV): N/A
• Indication: Refractory postpartum haemorrhage due to uterine atony when first-line uterotonics fail.
• Common adverse effects: Bronchospasm, diarrhoea, vomiting, fever, hypertension.
• Caution: Contraindicated in asthma; caution in significant cardiac/renal/hepatic disease—obstetric senior involvement.

💊 Codeine

• MOA: Weak opioid; prodrug partly converted to morphine (CYP2D6) → variable analgesia.
• Dose (PO): 15–60 mg PO q4–6h PRN (check maximums and combination products in BNF).
• Dose (IV): N/A
• Indication: Mild–moderate pain (often with paracetamol); cough suppression (limited).
• Practical: Constipation prophylaxis if ongoing; avoid “stacking” with other opioids unknowingly (combination analgesics).
• Caution: CYP2D6 ultra-rapid metabolisers (toxicity) vs poor metabolisers (no effect); follow BNF/BNFc restrictions in children and breastfeeding.

🧬 Dabigatran

• MOA: Direct thrombin (factor IIa) inhibitor.
• Dose (PO): AF commonly 150 mg BD (adjust for renal function/age per BNF). VTE regimens pathway-dependent.
• Dose (IV): N/A
• Indication: Stroke prevention in non-valvular AF; VTE treatment/secondary prevention (per pathway).
• Monitoring: No INR; check baseline/periodic renal function (renally cleared) and haemoglobin.
• Reversal: Idarucizumab for major bleeding/urgent surgery (see I section).
• Caution: Contraindicated in mechanical heart valves; renal impairment increases bleeding risk; dyspepsia common; interactions via P-gp.

⚡ Diazepam

• MOA: Benzodiazepine → enhances GABA-A activity (anticonvulsant, anxiolytic, muscle relaxant).
• Dose (IV/IM): 2–10 mg PRN (protocol dependent; titrate slowly IV).
• Dose (PO): 2–10 mg PO PRN (short course).
• Indication: Acute seizures/status (some pathways); alcohol withdrawal; acute agitation; muscle spasm.
• Monitoring: RR, SpO2, BP, sedation score; be ready for airway support especially if co-ingestions.
• Caution: Respiratory depression/hypotension—risk increased with opioids/alcohol; prolonged sedation in elderly/hepatic impairment.

💔 Digoxin immune Fab

• MOA: Antibody fragments bind free digoxin → neutralises toxicity and promotes renal elimination.
• Dose (IV): Specialist-guided (based on ingested amount/level and severity).
• Dose (PO): N/A
• Indication: Life-threatening digoxin toxicity (ventricular arrhythmias, severe bradyarrhythmia, hyperkalaemia, haemodynamic instability).
• Monitoring pearl: Digoxin levels become unreliable after Fab (assays measure bound + unbound). Treat clinically (rhythm, K+).
• Caution: Hypokalaemia can follow reversal—monitor K+ closely; involve NPIS/cardiology.

🫀 Diltiazem

• MOA: Non-dihydropyridine CCB → slows AV nodal conduction and decreases contractility.
• Dose (IV): 0.25 mg/kg bolus, may repeat 0.35 mg/kg; infusion 5–15 mg/h (protocol).
• Dose (PO): N/A (acute here)
• Indication: Rate control in stable AF with RVR (selected); stable SVT (selected).
• Monitoring: BP, HR, ECG; watch PR prolongation/bradycardia.
• Caution: Avoid in HFrEF, hypotension, pre-excitation syndromes (AF with WPW); interactions (CYP3A4).

💔 Dobutamine

• MOA: Predominantly β1 agonist (some β2) → ↑ inotropy, mild vasodilation.
• Dose (IV infusion): 2–20 microg/kg/min (titrate to perfusion; ICU/CCU protocol).
• Dose (PO): N/A
• Indication: Cardiogenic shock/low-output HF with adequate preload (specialist setting).
• Physiology pearl: Improves cardiac output; may reduce SVR—BP can fall if vasodilated (may need vasopressor).
• Caution: Tachyarrhythmias/ischaemia; requires close monitoring (often arterial line/central access).

💔 Dopamine

• MOA: Dose-dependent dopaminergic/β/α agonist effects (arrhythmogenic at higher doses).
• Dose (IV infusion): 5–20 microg/kg/min (titrate; local critical care protocol).
• Dose (PO): N/A
• Indication: Selected shock/hypotension states (less favoured than noradrenaline in sepsis).
• Practical: Central line preferred; treat extravasation promptly per protocol.
• Caution: High arrhythmia burden; avoid “renal-dose dopamine” as routine.

💊 Dihydrocodeine

• MOA: Opioid agonist → analgesia with sedation.
• Dose (PO): 30 mg PO q4–6h PRN (check max daily dose per BNF).
• Dose (IV): N/A
• Indication: Moderate pain (step-up from non-opioids).
• Practical: Add laxative if ongoing; consider antiemetic for nausea; assess driving/falls risk.
• Caution: Respiratory depression and delirium risk in frailty; renal/hepatic impairment; avoid with other sedatives where possible.

🧠 Droperidol

• MOA: Dopamine receptor antagonist with α-blockade → antiemetic/sedative effects.
• Dose (IV): 1.25–2.5 mg IV q4h PRN (local policies vary; ECG considerations).
• Dose (PO): N/A
• Indication: Antiemetic (including migraine-associated nausea); sometimes acute agitation (protocol dependent).
• Monitoring: Consider baseline QTc and electrolytes (K/Mg); recheck if repeated doses.
• Caution: QT prolongation/torsades risk; EPS/NMS; avoid with multiple QT-prolongers and in marked QTc prolongation.

🩸 Enoxaparin (Clexane)

• MOA: LMWH → potentiates antithrombin → inhibits factor Xa > IIa.
• Dose (SC): Treatment: 1 mg/kg q12h or 1.5 mg/kg OD (indication-dependent). Prophylaxis regimens differ—follow local policy.
• Dose (PO/IV): N/A
• Indication: VTE treatment/prevention; ACS pathways (e.g., NSTEMI/UA) per local guidance.
• Monitoring: Baseline FBC/platelets, renal function; anti-Xa only in selected cases (pregnancy, extremes of weight, renal impairment).
• Caution: Bleeding; renal impairment (accumulation); neuraxial/spinal procedures timing; HIT risk (lower than UFH but not zero). Protamine partially reverses.

🧠 Esmolol

• MOA: Ultra-short acting β1 blocker → rate control with rapid offset.
• Dose (IV): 500 microg/kg loading → 50–300 microg/kg/min infusion (titrate).
• Dose (PO): N/A
• Indication: Aortic dissection rate control; peri-arrest tachyarrhythmias (selected).
• Monitoring: BP/HR/ECG continuously; stop quickly if hypotension/bradycardia.
• Caution: Acute HF, hypotension, bradycardia; bronchospasm risk (less than nonselective but still possible).

🔥 Esomeprazole (Nexium)

• MOA: Proton pump inhibitor → suppresses gastric acid secretion.
• Dose (IV): 80 mg bolus → 8 mg/hour infusion (protocol-dependent; many trusts vary around endoscopy timing).
• Dose (PO): N/A (acute here)
• Indication: Non-variceal upper GI bleed (high-risk lesions; protocol-led).
• Practical: Does not replace urgent endoscopy/resuscitation; use alongside transfusion thresholds and haemostasis pathway.
• Caution: Generally well tolerated acutely; consider infection risk with prolonged use; check interactions in chronic use.

🧠 Etomidate

• MOA: GABA-A modulation → rapid hypnosis (induction agent), haemodynamically stable compared with propofol.
• Dose (IV): RSI induction commonly 0.3 mg/kg IV single bolus (follow local RSI protocol).
• Dose (PO): N/A
• Indication: RSI induction (selected settings where haemodynamic stability desired).
• Adverse effects: Myoclonus, nausea; transient adrenal suppression via 11β-hydroxylase inhibition.
• Caution: Avoid repeated dosing/infusion; consider alternatives in septic shock depending on local policy.

💉 Fentanyl

• MOA: Potent μ-opioid agonist → rapid analgesia (shorter duration than morphine).
• Dose (IV): 25–100 microg IV titrated; ~1 microg/kg often used (protocol dependent).
• Dose (PO): N/A (acute here)
• Indication: Severe pain; procedural analgesia/sedation adjunct; haemodynamic-friendly in many settings.
• Monitoring: RR, SpO2, BP, sedation score; consider capnography in procedural sedation.
• Reversal: Naloxone if opioid-induced respiratory depression.
• Caution: Respiratory depression; hypotension (less histamine release than morphine); rapid high-dose bolus can cause chest wall rigidity (rare).

🧠 Flumazenil

• MOA: Competitive antagonist at benzodiazepine binding site (GABA-A).
• Dose (IV): 0.2 mg increments up to 1 mg (titrate to ventilation/airway, not full wakefulness).
• Dose (PO): N/A
• Indication: Reversal of iatrogenic benzodiazepine over-sedation (selected cases).
• Monitoring: Re-sedation can occur (short half-life vs long-acting benzos) → observe and repeat if needed per protocol.
• Caution: 🚫 Avoid in chronic benzodiazepine use, seizure disorders, mixed overdoses (especially TCA) → seizures/arrhythmias.

🍸 Fomepizole

• MOA: Alcohol dehydrogenase inhibitor → prevents toxic metabolites (formate/oxalate).
• Dose (IV): 15 mg/kg load → 10 mg/kg q12h ×4 → then 15 mg/kg q12h until toxin cleared and pH normal.
• Dose (PO): N/A
• Indication: Methanol/ethylene glycol poisoning.
• Adjuncts: Folinic/folic acid for methanol; thiamine/pyridoxine for ethylene glycol (protocol-dependent); haemodialysis often required.
• Caution: Time-critical—contact NPIS early; monitor anion gap, osmol gap, pH, electrolytes, renal function.

🧠 Fosphenytoin

• MOA: Prodrug of phenytoin; stabilises neuronal Na+ channels (PE = phenytoin equivalents).
• Dose (IV): 15–20 mg PE/kg IV load at ≤150 mg PE/min (monitor ECG/BP).
• Dose (PO): N/A
• Indication: Status epilepticus (second-line per protocol).
• Advantages vs phenytoin: Can infuse faster; less local tissue injury; still requires cardiac monitoring.
• Caution: Hypotension/arrhythmias with rapid infusion; avoid in severe bradycardia/SA/AV block unless specialist-directed.

💧 Furosemide (Frusemide)

• MOA: Loop diuretic → inhibits Na-K-2Cl transporter in ascending loop; venodilation early may reduce preload.
• Dose (IV): 20–40 mg IV initially; titrate higher depending on diuretic exposure and renal function (protocol dependent).
• Dose (PO): N/A (acute use here)
• Indication: Acute pulmonary oedema; fluid overload.
• Monitoring: Urine output, weight, BP, electrolytes (K/Mg/Na), renal function.
• Caution: Hypovolaemia, electrolyte depletion, ototoxicity at high doses; may worsen AKI if intravascularly depleted.

💥 Glyceryl trinitrate (GTN)

• MOA: NO donor → ↑ cGMP → venodilation (↓ preload), some arterial dilation (↓ afterload), coronary vasodilation.
• Dose (IV): 5–200 microg/min infusion titrated to symptoms and BP (protocol dependent).
• Dose (PO): N/A (acute here)
• Indication: ACS/angina; acute pulmonary oedema (if BP allows).
• Monitoring: BP closely (risk hypotension); headache common; consider continuous monitoring in acute settings.
• Caution: Avoid in RV infarction, severe aortic stenosis, hypotension; contraindicated with PDE5 inhibitors (sildenafil/tadalafil) within relevant window.

📈 Glucagon

• MOA: Increases cAMP independently of β-receptors → improves inotropy/chronotropy; increases glucose via glycogenolysis.
• Dose (IV/IM/SC): β-blocker/CCB overdose: 3–10 mg IV bolus → 1–10 mg/h infusion if responsive. Hypoglycaemia: 1 mg IM/IV/SC (paeds: check BNF).
• Dose (PO): N/A
• Indication: β-blocker/CCB overdose; severe hypoglycaemia.
• Monitoring: HR/BP, glucose; response may be transient—plan definitive therapy (vasopressors/high-dose insulin for CCB).
• Caution: Vomiting (aspiration risk), hypotension, rare anaphylactoid reaction; less effective if glycogen depleted (malnutrition/alcohol).

🧠 Haloperidol

• MOA: Dopamine receptor antagonism (D2) → antipsychotic/sedative effects.
• Dose (IM/PO/IV): Use local delirium/agitation protocol (doses and routes vary; IV use is policy-dependent).
• Indication: Acute agitation/delirium (selected); psychosis.
• Monitoring: QTc, electrolytes (K/Mg), sedation score, EWS; consider ECG pre/post if risk factors.
• Caution: QT prolongation/torsades, EPS, NMS; increased stroke/mortality risk in dementia—use lowest dose and review frequently.

🩸 Heparin (Unfractionated)

• MOA: Potentiates antithrombin → inhibits thrombin (IIa) and factor Xa; rapid on/off; APTT-guided.
• Dose (IV): Bolus + infusion per local VTE/ACS protocol (APTT targets differ).
• Dose (PO): N/A
• Indication: VTE; ACS; bridging in selected patients; situations requiring rapid reversibility.
• Monitoring: APTT, platelets (HIT), Hb; assess bleeding risk regularly.
• Reversal: Protamine (see P) for significant bleeding/procedures.
• Caution: Bleeding; HIT; osteoporosis with prolonged use; ensure correct pump settings and line safety.

🩺 Hydralazine

• MOA: Direct arteriolar vasodilator → ↓ afterload.
• Dose (IV): 5–10 mg IV q20–40 min titrated to BP (protocol dependent).
• Dose (PO): N/A (acute here)
• Indication: Acute severe hypertension (including obstetric pathways where used).
• Monitoring: BP frequently; watch for reflex tachycardia and fetal monitoring in pregnancy.
• Caution: Reflex tachycardia, headache, hypotension; avoid precipitous BP drops (reduce uteroplacental perfusion).

🧠 Hydrocortisone

• MOA: Glucocorticoid with mineralocorticoid activity → supports vascular responsiveness to catecholamines; anti-inflammatory.
• Dose (IV): Adrenal crisis: 100 mg IV bolus → 50 mg IV q6h (then taper). Refractory septic shock: 50 mg IV q6h (ICU protocol).
• Dose (PO): N/A (acute)
• Indication: Acute adrenal insufficiency; vasopressor-refractory septic shock; severe asthma (protocol).
• Practical: In adrenal crisis also give IV fluids + treat precipitant; consider fludrocortisone long-term (endocrine).
• Caution: Hyperglycaemia, infection risk, delirium; GI protection may be needed if critically ill.

🔥 Hydroxocobalamin

• MOA: Binds cyanide → cyanocobalamin (non-toxic).
• Dose (IV): 5 g IV over ~15 min; repeat if needed (protocol).
• Dose (PO): N/A
• Indication: Suspected cyanide poisoning (e.g., smoke inhalation + severe lactic acidosis/collapse).
• Practical: Treat empirically if high suspicion—do not wait for cyanide level; coordinate with fire smoke inhalation pathway.
• Caution: Turns skin/urine red; can interfere with lab assays and dialysis sensors—warn teams early.

💉 Hydromorphone

• MOA: μ-opioid agonist → potent analgesia.
• Dose (IV): 1–2 mg IV every 3–6 h (titrate carefully; local UK availability varies).
• Dose (PO): N/A (acute here)
• Indication: Severe pain (often when morphine unsuitable/ineffective).
• Equivalence pearl: Approx ~1 mg IV hydromorphone ≈ ~7 mg IV morphine (rule-of-thumb; use local equivalence tables).
• Caution: Respiratory depression, hypotension; higher delirium/falls risk in frail/elderly; renal/hepatic impairment—start low.

🧩 Idarucizumab (Praxbind)

• MOA: Monoclonal antibody fragment binds dabigatran with high affinity → immediate reversal.
• Dose (IV): 5 g IV total (2 × 2.5 g doses within 15 min).
• Dose (PO): N/A
• Indication: Dabigatran reversal for life-threatening bleeding or urgent surgery/procedure.
• Monitoring: Clinical haemostasis; repeat coagulation tests per protocol; consider rebound anticoagulation in prolonged absorption/renal failure.
• Caution: Thrombosis risk after reversal—restart anticoagulation when safe (specialist decision).

🍬 Insulin (Soluble / Regular)

• MOA: Facilitates glucose uptake; drives K+ intracellularly; metabolic support in CCB overdose.
• Dose (IV): Hyperkalaemia: 5–10 units IV + glucose (protocol). CCB overdose: 1 unit/kg bolus → infusion 0.1–1 unit/kg/h with glucose. DKA/HHS: per protocol (often 0.1 unit/kg/h).
• Dose (PO): N/A
• Indication: Hyperkalaemia; CCB overdose; DKA/HHS.
• Monitoring: Capillary glucose (frequent), K+ and phosphate, ECG, infusion line safety; adjust glucose infusion to maintain euglycaemia.
• Caution: Hypoglycaemia/hypokalaemia—common; ensure potassium replacement plan and close nursing monitoring.

🧠 Ketamine

• MOA: NMDA receptor antagonist → dissociative anaesthesia and analgesia; preserves airway reflexes more than many agents (not absolute).
• Dose (IV): Analgesia 0.1–0.5 mg/kg; procedural sedation 0.5–1 mg/kg; RSI induction ~1–2 mg/kg (protocol dependent).
• Dose (PO): N/A
• Indication: Analgesia, procedural sedation, RSI induction (selected cases), severe asthma (some pathways).
• Physiology: Sympathomimetic (↑ HR/BP); bronchodilation can help in severe asthma.
• Caution: Emergence phenomena, hypersalivation, rare laryngospasm; caution in severe hypertension/ischaemic heart disease and certain ocular/raised ICP scenarios (local policy).

🫀 Labetalol

• MOA: Combined α1 and β blockade → ↓ BP with less reflex tachycardia.
• Dose (IV): 20–80 mg bolus q10 min PRN; infusion per protocol (especially obstetric).
• Dose (PO): Chronic dosing per BNF/obstetric protocol.
• Indication: Hypertensive emergencies; severe hypertension in pre-eclampsia/eclampsia pathways.
• Monitoring: BP/HR; watch for fetal bradycardia in pregnancy (monitor as per obstetric protocol).
• Caution: Asthma/bronchospasm, bradycardia, heart block, decompensated HF; caution in cocaine intoxication (local guidance varies).

🧠 Levetiracetam

• MOA: SV2A modulation → reduces neurotransmitter release (broad-spectrum anticonvulsant).
• Dose (IV): Often 1–3 g load (weight-based options exist; protocol dependent).
• Dose (PO): Commonly 500–1500 mg BD (titrate; renal adjustment).
• Indication: Seizures; status epilepticus second-line (many UK pathways); seizure prophylaxis in selected neurosurgical contexts.
• Monitoring: Renal function; neuropsychiatric side effects (irritability, mood change) especially in younger patients.
• Caution: Sedation, agitation/irritability; dose adjust in renal impairment.

⚡ Lorazepam

• MOA: Benzodiazepine → enhances GABA-A inhibitory effect (first-line for convulsive status).
• Dose (IV): Status epilepticus dosing per local protocol (commonly 4 mg IV, repeat once if ongoing seizures).
• Dose (PO): N/A (acute)
• Indication: Convulsive status epilepticus; severe agitation (selected).
• Practical: Treat glucose/oxygen first; if seizures persist after benzo, move promptly to second-line (levetiracetam/phenytoin/valproate per policy).
• Caution: Respiratory depression and hypotension—prepare airway/ventilation support.

🌀 Magnesium sulfate

• MOA: Membrane stabiliser; suppresses early afterdepolarisations (torsades); anticonvulsant in eclampsia; bronchodilator adjunct in asthma.
• Dose (IV): Torsades: 2 g IV over 10–15 min. Severe asthma: 2 g IV over ~15 min. Eclampsia: loading + infusion per obstetric protocol.
• Dose (PO): N/A
• Indication: Torsades de pointes; pre-eclampsia/eclampsia seizure prophylaxis/treatment; severe asthma exacerbation.
• Monitoring: RR, reflexes, urine output, BP; ECG if arrhythmia.
• Caution: Renal impairment (accumulation), myasthenia gravis, heart block; toxicity → respiratory depression and loss of reflexes (treat with calcium in severe toxicity per protocol).

🧠 Mannitol

• MOA: Osmotic agent → draws water from brain into intravascular space; decreases ICP.
• Dose (IV): 0.25–1 g/kg bolus (protocol dependent).
• Dose (PO): N/A
• Indication: Raised ICP / impending herniation (specialist neuro/ICU protocol).
• Monitoring: Serum osmolality, Na+, creatinine, urine output; assess volume status and haemodynamics.
• Caution: Pulmonary oedema/volume overload risk; renal failure; avoid repeated dosing without monitoring osmolality.

🌀 Metoclopramide

• MOA: D2 antagonist in CTZ; prokinetic (↑ gastric emptying); weak 5-HT3 antagonist at higher doses.
• Dose (IV): 10 mg IV q6h PRN (use lowest effective dose; slow IV can reduce akathisia).
• Dose (PO): If used, short-term only per BNF.
• Indication: Nausea/vomiting; gastroparesis; migraine-associated nausea (selected).
• Adverse effects: Akathisia, dystonia, EPS, tardive dyskinesia (risk increases with duration).
• Caution: Parkinson’s disease, epilepsy; avoid long courses; caution in young adults (dystonia risk) and elderly (EPS/delirium).

🧬 Methylergometrine (Methylergonovine) *

• MOA: Ergot alkaloid → sustained uterine contraction + vasoconstriction.
• Dose (IM): 200 microg; may repeat q2–4h (protocol dependent).
• Dose (IV): Avoid if possible; if used, give very slowly under senior supervision.
• Dose (PO): N/A
• Indication: PPH due to uterine atony (where used).
• Caution: Contraindicated in hypertension/pre-eclampsia/CVD due to vasoconstriction and stroke risk. *Not licensed in UK—follow local guidance.

🧠 Methohexital

• MOA: Ultra-short acting barbiturate → sedation/hypnosis.
• Dose (IV): ~1 mg/kg IV then 0.5 mg/kg q2–5 min PRN (ED/anaesthetic protocol).
• Dose (PO): N/A
• Indication: Procedural sedation (specialist setting).
• Caution: Respiratory depression, hypotension, laryngospasm risk—airway-ready environment only.

🧠 Methylprednisolone (Solu-Medrone)

• MOA: Systemic corticosteroid → anti-inflammatory/immunosuppressive.
• Dose (IV): Severe asthma/allergy and other indications vary widely—use local pathway (often weight-based).
• Dose (PO): N/A (acute)
• Indication: Severe asthma exacerbation; acute hypersensitivity reactions; selected pneumonias (e.g., PCP with hypoxaemia—specialist).
• Monitoring: Glucose, mental state, infection; consider GI protection in high-risk.
• Caution: Hyperglycaemia, delirium, infection risk; avoid masking sepsis without treating cause.

🧠 Midazolam

• MOA: Benzodiazepine → enhances GABA-A; short-acting sedative.
• Dose (IV): Procedural sedation/ventilation sedation/RSI adjunct dosing per protocol; buccal/intranasal routes exist (BNFc/ambulance protocols).
• Dose (PO): N/A (acute)
• Indication: Procedural sedation; ventilated sedation; seizure rescue (route dependent).
• Monitoring: RR, SpO2, BP, sedation score; capnography recommended for procedural sedation.
• Caution: Respiratory depression, hypotension—risk increased with opioids/alcohol and in frailty/OSA.

🧡 Misoprostol

• MOA: PGE1 analogue → uterotonic + cervical ripening.
• Dose (PR/PO/SL): PPH commonly 600–1000 microg PR (protocol dependent). Induction/cervical ripening varies by trust protocol.
• Dose (IV): N/A
• Indication: Labour induction/cervical ripening; PPH adjunct.
• Adverse effects: Pyrexia, shivering, diarrhoea; uterine hyperstimulation possible.
• Caution: Prior uterine surgery (rupture risk); follow obstetric protocol and fetal monitoring standards.

💉 Morphine sulfate

• MOA: μ-opioid agonist → analgesia with sedation; histamine release can contribute to hypotension/itch.
• Dose (IV): 2–10 mg IV titrated (often ~0.05–0.1 mg/kg), reassess frequently.
• Dose (PO): Not for acute IV-focused use here (oral regimens follow BNF).
• Indication: Moderate–severe pain (e.g., trauma, ACS pain if appropriate).
• Monitoring: RR, SpO2, BP, sedation score; constipation prophylaxis if ongoing.
• Caution: Respiratory depression; hypotension; accumulation in renal impairment (active metabolites); delirium/falls risk in frail older adults.

💉 Naloxone

• MOA: Competitive opioid receptor antagonist → reverses respiratory depression.
• Dose (IV): 0.04–0.4 mg IV titrated to adequate respirations (not full wakefulness); repeat or infusion if needed. IM/IN routes exist (protocol).
• Dose (PO): N/A
• Indication: Opioid overdose with respiratory depression; iatrogenic opioid toxicity.
• Monitoring: Observe for re-sedation (naloxone shorter than many opioids); consider capnography; ensure airway protection.
• Caution: Precipitates acute withdrawal (agitation, vomiting, sympathetic surge); pulmonary oedema rare; use careful titration especially in chronic opioid users.

💊 Nifedipine

• MOA: Dihydropyridine CCB → smooth muscle relaxation; used as tocolytic.
• Dose (PO): 10–20 mg initially then 10–20 mg q4–6h (protocol dependent).
• Dose (IV): N/A
• Indication: Tocolysis in preterm labour (specialist obstetric pathway).
• Monitoring: Maternal BP/HR; fetal monitoring as per obstetric protocol.
• Caution: Hypotension; avoid combination with IV magnesium sulfate where contraindicated by protocol (risk hypotension/neuromuscular effects).

🧠 Nimodipine

• MOA: Cerebral artery-selective CCB → reduces risk of delayed cerebral ischaemia after SAH.
• Dose (PO): 60 mg PO every 4 h (standard SAH protocols; adjust if hypotension).
• Dose (IV): N/A
• Indication: Aneurysmal SAH to reduce vasospasm-related ischaemia.
• Monitoring: BP (hypotension is dose-limiting); neuro observations.
• Caution: Hypotension may worsen cerebral perfusion—coordinate with neurocritical care.

🧠 Noradrenaline (Norepinephrine)

• MOA: Potent α1 > β1 agonist → ↑ SVR and supports MAP; modest inotropy.
• Dose (IV infusion): Titrate to MAP/BP per local protocol (units vary by trust; often central-line infusion).
• Dose (PO): N/A
• Indication: Septic shock and other vasodilatory shock states after fluids; peri-arrest hypotension (critical care).
• Monitoring: Continuous BP (arterial line preferred), lactate/perfusion markers, urine output; central access and pump safety.
• Caution: Extravasation and limb ischaemia risk; arrhythmias; ensure adequate volume status to avoid excessive vasoconstriction.

📉 Sodium nitroprusside

• MOA: NO release → arterial and venous vasodilation; rapid onset/offset.
• Dose (IV infusion): Start ~0.3 microg/kg/min, titrate; max 10 microg/kg/min (specialist/ICU protocol).
• Dose (PO): N/A
• Indication: Hypertensive emergencies requiring rapid titration (specialist setting).
• Monitoring: Continuous BP (arterial line), acid–base status; duration and dose limits important.
• Caution: Cyanide/thiocyanate toxicity with prolonged/high-dose infusions; methemoglobinaemia; avoid without critical care monitoring.

🧃 Octreotide

• MOA: Somatostatin analogue → ↓ splanchnic blood flow and portal pressure (variceal bleed); inhibits insulin secretion (sulfonylureas).
• Dose (IV): Variceal bleed: 50 microg bolus → 50 microg/hour infusion.
• Dose (SC): Sulfonylurea hypoglycaemia: 50–100 microg SC q6–12h (protocol dependent).
• Dose (PO): N/A
• Indication: Bleeding oesophageal varices; sulfonylurea-induced hypoglycaemia (prevents recurrence).
• Practical: In variceal bleed, use alongside antibiotics and urgent endoscopy pathway; resuscitate first.
• Caution: Bradycardia, glucose disturbances, biliary stasis/gallstones with prolonged use; monitor glucose and HR.

🧠 Olanzapine

• MOA: Atypical antipsychotic → dopamine and 5-HT2 antagonism (sedating).
• Dose (IM/PO/ODT): Use local agitation pathway (no IV form).
• Dose (IV): N/A
• Indication: Acute agitation/psychosis (selected cases) when de-escalation fails.
• Monitoring: Sedation score, BP, ECG if QT risk; watch airway if combined sedatives.
• Caution: Sedation/orthostatic hypotension; avoid rapid combination with benzodiazepines unless protocol supports; caution in elderly/dementia.

💉 Ondansetron

• MOA: 5-HT3 receptor antagonist → central and peripheral antiemetic.
• Dose (IV): 4–8 mg IV q4–6h PRN (check max daily dose per BNF).
• Dose (PO): If used, follow BNF.
• Indication: Nausea/vomiting (post-op, gastroenteritis, medication related); chemotherapy-related (specialist protocols).
• Monitoring: QTc if risk factors (electrolyte derangement, other QT drugs); correct K/Mg.
• Caution: QT prolongation (rare torsades), constipation; caution with other QT-prolongers and congenital long QT.

🤱 Oxytocin (Syntocinon)

• MOA: Oxytocin receptor activation → uterine smooth muscle contraction.
• Dose (IV/IM): PPH and induction/augmentation regimens are trust protocol-led (avoid fixed dosing here—BNF/obstetric guidance).
• Dose (PO): N/A
• Indication: Induction/augmentation of labour; prevention/treatment of postpartum haemorrhage.
• Monitoring: Uterine activity and fetal heart monitoring during induction; BP/HR and bleeding in PPH.
• Caution: Uterine hyperstimulation → fetal distress; water intoxication with prolonged high-dose infusion (rare); uterine rupture risk in scarred uterus.

💊 Paracetamol

• MOA: Analgesic/antipyretic via central mechanisms (prostaglandin modulation).
• Dose (IV): 1 g IV q6h (max usually 4 g/day; reduce max in low body weight, malnutrition, hepatic impairment—BNF).
• Dose (PO): 500–1000 mg PO q4–6h PRN (max per BNF; watch combination products).
• Indication: Mild–moderate pain, fever; opioid-sparing cornerstone.
• Practical: Always check total daily dose across combination products (cold/flu meds, co-codamol/co-dydramol).
• Caution: Hepatotoxic in overdose; reduce max dose in chronic alcohol excess/liver disease/low body weight; ensure safe dispensing to avoid duplicate therapy.

🧠 Phenobarbital

• MOA: Barbiturate → prolongs GABA-A chloride channel opening; anticonvulsant/sedative.
• Dose (IV): Weight-based loading per refractory status epilepticus protocol (ICU/ED).
• Dose (PO): N/A (acute here)
• Indication: Refractory status epilepticus (specialist/ICU).
• Monitoring: Airway/ventilation, BP, ECG; often requires intubation and ICU care.
• Caution: Profound respiratory depression and hypotension; drug interactions via enzyme induction.

🧠 Phenytoin

• MOA: Voltage-gated Na+ channel stabilisation → limits seizure propagation.
• Dose (IV): 15–20 mg/kg load at ≤50 mg/min (continuous ECG/BP monitoring). Maintenance per protocol.
• Dose (PO): Maintenance per BNF; therapeutic drug monitoring important.
• Indication: Status epilepticus (second-line); seizure prophylaxis (selected).
• Monitoring: ECG/BP during infusion; levels (free level if hypoalbuminaemia); watch for nystagmus/ataxia.
• Caution: Arrhythmias/hypotension if rapid; extravasation tissue injury (“purple glove”); extensive CYP interactions; teratogenic risk.

💊 Prednisolone (Prednisone is the US equivalent)

• MOA: Systemic glucocorticoid → reduces airway inflammation and immune activation.
• Dose (PO): Acute asthma commonly 30–50 mg daily (confirm local/BTS/BNF guidance; paeds dosing differs).
• Dose (IV): N/A (use IV hydrocortisone/methylpred if unable to take PO per protocol).
• Indication: Asthma exacerbation; allergic/inflammatory conditions; selected pneumonias (specialist guidance).
• Practical: Early steroids reduce relapse/admission in asthma; taper generally not needed for short courses but check if prolonged.
• Caution: Hyperglycaemia, mood change, infection risk, GI irritation; caution in uncontrolled diabetes and active infection (treat cause).

🧠 Propofol

• MOA: GABA-A agonist → hypnosis/sedation; antiemetic properties.
• Dose (IV): Induction/sedation infusions per ED/ICU protocol (varies widely; requires airway-ready setting).
• Dose (PO): N/A
• Indication: Induction of anaesthesia; sedation for ventilation; procedural sedation (specialist).
• Monitoring: Continuous BP/ECG/SpO2; capnography; often requires airway support.
• Caution: Hypotension/bradycardia; respiratory depression; propofol infusion syndrome with prolonged high-dose (ICU vigilance).

🧬 Protamine sulfate

• MOA: Positively charged peptide binds heparin → neutralises anticoagulant effect.
• Dose (IV): ~1 mg per 100 units heparin (max 50 mg); infuse slowly (≤5 mg/min). Dose depends on time since last heparin dose.
• Dose (PO): N/A
• Indication: UFH reversal (partial LMWH reversal).
• Monitoring: APTT/anti-Xa (protocol), bleeding control, BP during infusion.
• Caution: Anaphylaxis (fish allergy, prior protamine/vasectomy exposure), hypotension if rapid; rebound anticoagulation possible if under-dosed.

🧩 Rocuronium

• MOA: Non-depolarising neuromuscular blocker → paralysis for intubation.
• Dose (IV): RSI paralysis dose per protocol (commonly ~1 mg/kg).
• Dose (PO): N/A
• Indication: RSI paralysis; facilitation of ventilation/intubation.
• Practical: Paralysis ≠ sedation—ensure ongoing sedation/analgesia after intubation.
• Caution: Prolonged paralysis; difficult neuro assessment; hepatic impairment can prolong effect.

🧩 Rivaroxaban

• MOA: Direct factor Xa inhibitor.
• Dose (PO): AF: 20 mg OD with food (renal adjust). VTE: 15 mg BD ×21 days then 20 mg OD.
• Dose (IV): N/A
• Indication: Stroke prevention in non-valvular AF; VTE treatment/secondary prevention.
• Monitoring: Renal function, LFTs, Hb; adherence is crucial due to short half-life.
• Caution: Bleeding; severe hepatic impairment; interactions (CYP3A4/P-gp); take with food where indicated for absorption.

🫁 Salbutamol

• MOA: β2 agonist → bronchodilation; also shifts K+ intracellularly (adjunct in hyperkalaemia).
• Dose (Neb): 2.5–5 mg nebulised; severe asthma uses repeated/continuous nebulisation per protocol.
• Dose (IV): Specialist-guided (not routine).
• Dose (PO): N/A (acute)
• Indication: Acute bronchospasm/asthma; COPD exacerbation with bronchospasm; adjunct in hyperkalaemia.
• Monitoring: HR, tremor, K+ (high-dose can cause hypokalaemia), response to therapy and PEFR where appropriate.
• Caution: Tachycardia, hypokalaemia, lactic acidosis in high-dose continuous therapy; caution in severe arrhythmias/ischaemic heart disease.

🧂 Sodium bicarbonate

• MOA: Buffers metabolic acidosis; alkalinises serum/urine; increases sodium load helpful in sodium-channel blockade (e.g., TCA).
• Dose (IV): Hyperkalaemia/severe acidosis: commonly 50 mmol IV (protocol). TCA: 1–2 mmol/kg bolus to target pH ~7.45–7.55 and narrow QRS. Salicylate alkalinisation per NPIS.
• Dose (PO): N/A
• Indication: TCA toxicity with QRS widening; severe metabolic acidosis; selected hyperkalaemia management; salicylate poisoning alkalinisation (specialist).
• Monitoring: ABG/VBG, electrolytes (Na/K/Ca), ECG (QRS), fluid balance.
• Caution: Hypernatraemia, fluid overload, alkalosis, hypocalcaemia; avoid over-correction; HF/CKD need careful volume management.

💉 Suxamethonium (Succinylcholine)

• MOA: Depolarising neuromuscular blocker → rapid paralysis (short duration).
• Dose (IV): RSI paralysis dose per protocol (commonly 1–1.5 mg/kg; IM options exist if no IV access).
• Dose (PO): N/A
• Indication: RSI paralysis when rapid onset/short duration desired.
• Practical: Consider rocuronium if contraindications present; ensure post-intubation sedation.
• Caution: Hyperkalaemia risk states (burns/crush after 48–72 h, neuromuscular disease, massive rhabdo), malignant hyperthermia, bradyarrhythmias; raised IOP/ICP considerations per protocol.

🫁 Terbutaline

• MOA: β2 agonist → relaxes uterine smooth muscle (tocolysis) and bronchodilation.
• Dose (SC): 250 microg every 20–30 min up to 3 doses (tocolysis protocol dependent).
• Dose (PO/IV): N/A (here)
• Indication: Short-term tocolysis in preterm labour (specialist obstetric); sometimes uterine relaxation for hyperstimulation (protocol).
• Monitoring: Maternal HR/BP, glucose, K+ if repeated; fetal monitoring as per obstetric protocol.
• Caution: Tachycardia, hypertension, arrhythmias; caution in cardiac disease, hyperthyroidism, poorly controlled diabetes.

💊 Tramadol

• MOA: Weak μ-opioid agonist + inhibits serotonin/noradrenaline reuptake.
• Dose (PO): 25–100 mg PO q4–6h PRN (max often ~400 mg/day; lower in older adults/renal impairment—BNF).
• Dose (IV): N/A (here)
• Indication: Moderate pain when alternatives unsuitable.
• Practical: Consider delirium risk in frailty; constipation prophylaxis if ongoing.
• Caution: Seizure risk; serotonin syndrome with SSRIs/SNRIs/MAOIs; respiratory depression still possible; avoid in uncontrolled epilepsy.

🟩 Vitamin K (Phytomenadione)

• MOA: Cofactor for synthesis of factors II, VII, IX, X → reverses warfarin effect (with time).
• Dose (IV): Serious bleeding on warfarin: 5–10 mg IV slowly (often with PCC per protocol).
• Dose (PO): Raised INR without bleeding: low-dose PO per local guidance (BNF).
• Indication: Warfarin reversal; vitamin K deficiency.
• Practical: For life-threatening bleeding, vitamin K alone is too slow—use PCC/FFP per haemostasis pathway.
• Caution: Anaphylactoid reactions if IV too rapid; may cause warfarin resistance for days (plan re-anticoagulation).

🩸 Warfarin

• MOA: Vitamin K antagonist → inhibits vitamin K epoxide reductase → ↓ factors II, VII, IX, X (and proteins C/S).
• Dose (PO): Initiation commonly 5 mg daily then adjust to INR (local protocol varies; lower starts in frail/elderly).
• Dose (IV): Rare (usually oral).
• Indication: VTE treatment/prevention; AF (selected); mechanical heart valves (key indication).
• Monitoring: INR target depends on indication (valves often higher); frequent monitoring during initiation and with interacting drugs.
• Interactions: Many (antibiotics, amiodarone, antifungals, alcohol, diet changes); check INR after starting/stopping interacting meds.
• Reversal: Vitamin K ± PCC depending on bleeding severity/INR; follow local haemostasis guideline.
• Caution: Teratogenic (avoid pregnancy); bleeding risk; initial procoagulant phase (protein C/S drop)—bridging needed in some contexts.