ICU 360

Antidote, indication and adult dose for the agents an Indian ICU should be able to access.

Definition

Antidotes are few but time-critical. Each ICU should know which antidotes are stocked on site, in the hospital, and regionally.

At the bedside

1
Know your stock
Keep an antidote list with location, quantity and alternative suppliers; review annually.
2
Dose for the whole course
Many antidotes need large total quantities (e.g. glucagon, NAC, hydroxocobalamin); order more early.
3
Hypoglycaemic agents
Sulfonylurea overdose: dextrose for immediate correction, then octreotide 50 mcg q6h to prevent recurrence; observe 24 h.
4
Methaemoglobinaemia
Dapsone, nitrites, aniline dyes, local anaesthetics: methylene blue 1-2 mg/kg if MetHb > 20-30% or symptomatic (not in G6PD deficiency).
5
Cyanide
Smoke inhalation with lactate > 8 mmol/L, coma, shock: hydroxocobalamin 5 g IV; thiosulfate alternative.
6
Isoniazid
Refractory seizures (common with TB drugs in India): pyridoxine 1 g per g ingested (5 g if unknown) plus benzodiazepines.

Sulfonylurea hypoglycaemia

SC/IV

Methaemoglobinaemia

Cyanide

Isoniazid seizures

Poison	Antidote	Adult dose (summary)
Opioids	Naloxone	0.04-0.4 mg IV titrated; infusion 2/3 effective dose/h
Paracetamol	Acetylcysteine	200 mg/kg over 4 h, then 100 mg/kg over 16 h
Methanol / ethylene glycol	Fomepizole or ethanol	Fomepizole 15 mg/kg then 10 mg/kg q12h; ethanol to 100-150 mg/dL
Sodium-channel blockers (TCA)	Sodium bicarbonate	1-2 mEq/kg bolus, repeat
Calcium-channel blockers	Calcium, high-dose insulin	CaCl2 10% 10-20 mL; insulin 1 units/kg bolus then 1-10 units/kg/h
Beta-blockers	Glucagon, high-dose insulin	Glucagon 5-10 mg IV then 3-5 mg/h
Digoxin / oleander	Digoxin Fab	Acute 2-5 vials titrated; arrest 10 vials
Local anaesthetics	Lipid emulsion 20%	1.5 mL/kg then 0.25 mL/kg/min
Benzodiazepines	Flumazenil (rarely)	0.2 mg IV increments; avoid in mixed overdose/seizure risk
Organophosphates	Atropine (± oxime)	See agrochemical module
Cyanide	Hydroxocobalamin	5 g IV
Methaemoglobinaemia	Methylene blue	1-2 mg/kg IV
Isoniazid	Pyridoxine	1 g per g ingested (5 g empirical)
Sulfonylureas	Octreotide	50 mcg SC q6h
Heparin	Protamine	1 mg per 100 units (see haematology)
Warfarin	Vitamin K + PCC	See haematology module

Red flag · call your senior now

Recurrent hypoglycaemia after sulfonylurea ingestion: may last > 24 h (especially glibenclamide and in renal failure).

Pitfall

Flumazenil in an unknown overdose: may precipitate seizures (TCA co-ingestion, benzodiazepine dependence).

Pearl

In methylene blue-refractory methaemoglobinaemia think G6PD deficiency or sulfhaemoglobinaemia; consider exchange transfusion.

Test yourself

Module quiz · score 70% to complete the module

Methanol and other toxic alcohols

Educational reference for trained clinicians. Check doses against your hospital protocol and the patient in front of you.