Adult Medical Emergency Handbook - Scottish Intensive Care Society

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Toxicity
Serious toxicity from pure benzodiazepines is uncommon
Management
• Consider need for gut decontamination if present within 1 hour of
ingestion
• If significantly reduced conscious level or respiratory depression,
then call 2222 for urgent endotracheal intubation and ventilatory
support in a critical care area
• Flumazenil (Anexate®), a benzodiazepine antagonist, may be used
if immediate access to critical care is not available. It has a short
half-life (around 1 hour) and can provoke seizures, especially in
patients with:
1. Pre-existing epilepsy
2. Benzodiazepine-dependence
3. Mixed overdose, particularly common after tricyclic
antidepressants
FLUMAZENIL should not be used as a ‘diagnostic test’.
SALICYLATES
Features
Vomiting, tinnitus, deafness. In severe cases confusion, seizures,
metabolic acidosis, pulmonary oedema and coma may occur.
Toxicity
Likely if >250 mg/kg ingested; >500 mg/kg can cause severe toxicity/
death.
Management
• Give activated charcoal if >120 mg/kg ingested less than 1 hour ago.
• It can take several hours to reach peak plasma concentrations.
Salicylate concentrations should be checked in patients who have
ingested >120 mg/kg.
• In symptomatic patients: check at 2 hours post-ingestion, then
repeat after further 2 hours in case of on-going drug absorption.
• In asymptomatic patients: check at 4 hours post-ingestion.
• In patients with features of toxicity, a repeat level should be
checked in case of prolonged drug absorption, and repeated until
levels are falling.
• Poisoning severity is indicated by plasma salicylate
concentrations taken together with clinical and biochemical
264 adult medical emergencies handbook | NHS LOTHIAN: UNIVERSITY HOSPITALS DIVISION | 2009/11