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 (1 st 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         S L E B The cholinergic toxidrome =“DUMBELS”: D   Diaphoresis Diarrhoea (and abdo cramps) U  urination M  Miosis (or mydriasis)    Bronchospasm Bronchorrhoea Bradycardia  Emesis  Lacrimation  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