Toxidromes and Drug Ingestions

Toxidromes and

Drug Ingestions

Toxidromes What is a Toxidrome?

A constellation of clinical signs that may suggest a particular type of ingestion

Toxidromes may indicate what type of drugs a patient has taken if they are unable or unwilling to tell you

Toxidromes The most common toxidromes seen

are: Anticholingeric Cholinergic Sympathomimetic Sedative Hallucinogenic Serotonergic

Anticholinergic Toxidromes

Anticholinergic Toxidrome Due to drugs that block muscarinic

and nicotine acetylcholine receptor Antihistamines (1st generation) Tricyclic antidepressants Antitussives (cough mixtures) Antipsychotics Anticonvulsants Antimuscularinic drugs

Atropine Scopolamine Ipatroprium bromide

Plants Mushrooms Datura

Anticholinergic Toxidrome The anticholinergic toxidrome

consists of: Delirium + peripheral antimuscarinic effects

Mad as a hatter Confusion/hallucinations/seizure/coma

Red as a beet Flushed skin

Blind as a bat Mydriasis

Hot as a hare Hyperthermia

Dry as a bone Dry skin, urinary retention, ileus

Cholinergic Toxidromes

Cholinergic Toxidrome

Due to drugs that activate acetylcholine receptor ie the opposite of anticholinegric

toxidromes

Cholinergic Toxidrome Caused by:

Organophosphate insecticides Carbamate insecticides Chemical warfare agents eg Ricin, Tabun,

Soman, VX Alzheimer's medication eg donepezil Agents used for myasthenia gravis

Neostigmin Edrophonium Pilocarpine Phyostigmine

Cholinergic Toxidrome The cholinergic toxidrome =“DUMBELS”: D

Diaphoresis Diarrhoea (and abdo cramps)

U urination

M Miosis (or mydriasis)

B Bronchospasm Bronchorrhoea Bradycardia

E Emesis

L Lacrimation

S Salivation

Sympathomimetic Toxidromes

Sympathomimetic Toxidrome

Act via stimulation of sympathetic nervous system

Toxidrome – everything stimulated Hypertension Tachycardia Tachypnoea Hyperthermia Agitation Dilated pupils (usually) Diaphoresis/flushing

c.f: anticholinergic – dry

Sympathomimetic Toxidrome

In New Zealand the most commonly seen sympathomimetic ingestion is methamphetamine

Can also be seen with Alpha receptor agonists

Phenylephrine eg OTC cold preparations eg - coldrex Beta receptor agonist

Salbutamol Theophylline Caffeine

Alpha and beta agonists Amphetamine Cocaine Pseudo/ephedrine MDMA (ecstasy)

Sedative or Hypnotic

Toxidromes

Sedative or Hypnotic Toxidrome

Caused by any medication that causes CNS depression, such as: Benzodiazepines Barbiturates Alcohols Opioids Anticonvulsants Antipsychotics

Sedative or Hypnotic Toxidrome

Toxidrome Decreased Level of consciousness Hypoventilation Hypotension Bradycardia

Opioids + barbiturates also cause Miosis Hypothermia

Hallucinogenic Toxidromes

Hallucinogenic Toxidrome As it sounds, this is caused by drugs

and agents that cause hallucinations Amphetamine Cannaboids Cocaine LSD PCP Magic mushrooms (Psilocybin spp.)

Hallucinogenic Toxidrome Primarily presents with hallucination

Also can present with: Frank psychosis Panic attacks and anxiety Sympathomimetic symptoms esp.

tachycardia, hypertension and fever

Serotonergic Toxidromes

Serotonergic Toxidrome

A collection of signs and symptoms produced by excess serotonin in the central, peripheral and autonomic nervous systems

Serotonergic Toxidrome

Multiple medications can cause serotonergic toxidrome (or serotonin syndrome) Most commonly occurs when ≥ 2

medications which affect either serotonin reuptake or metabolism are given, but can also occur with a single agent

Serotonergic Toxidrome Associated with:

Selective serotonin reuptake inhibitors (SSRI -antidepressants) Eg paroxtetine, fluoxetine

Serotonin noradrenalin reuptake inhibitors (SNRI –antidressants)

Eg venlafaxine, citaloprma Tricyclic antidepressants Monoamine oxidase iunhibitors (Block serotonin break down –

used as antidepressants) Eg moclobmide

Analgesic Eg pethidine, tramadol, fentanyl

Antiemetics Eg metoclopramide, ondansteron

Anticonvulsants Eg valproaic acid

Dietary supplements Eg St johns wort, ginseng

Serotonergic Toxidrome Produces wide variety of signs and

symptoms due to CNS, peripheral and autonomic dysfunction Most commonly produces

Tremor Hyperreflexia and muscle rigidity esp in the

legs Clonus Fever Tachycardia and hypertension