Læknaneminn - 01.10.1996, Page 92

Overdoses and poisonings: physiological responses
• An anticholinergic agent causes dry skin and a prof-
ound decrease in bowel motility perceived as a qui-
eting of bowel sounds.
B. Cholinergic Toxidromes
1. Muscarinic toxidrome
There are two toxidromes associated with cholinerg-
ic poisoning, one caused by muscarinic and the other
by nicotinic agonists.
Symptoms of muscarinic poisoning are easily rem-
embered by the mnemonic DUMB BELS:
D - Diarrhoea: frequent discharge of more or less
liquid faeces
U - Urination discharge of urine from the bladder
M - Miosis excessive contraction of the pupil
B - Bradycardia abnormal siowness of the pulse
B - Bronchorrhea bronchitis with profuse
expectoration
E - Emesis the act of vomiting
L - Lacrimation secretion of tears
S - Salivation secretion of saliva
Among the potential toxins causing this syndrome
are the following:
• Organophosphates
• Certain species of mushroom
• Betel nut
• Carbachol
• Pilocarpine
• Acetylcholine
2. Nicotinic toxidrome
The symptoms of the nicotinic toxidrome include:
• Tachycardia
• Hypertension
• Muscle fasciculations
• Weakness or paralysis
Toxins responsible for this include:
• Insecticides (nicotinic)
• Tobacco
• Indian tobacco
• Black widow spider venom
C. Anticholinergic Toxidrome
A large number of drugs and toxins have ant-
icholinergic properties. They cause a variety of symp-
toms which may include:
• Dry skin
• Hyperthermia
• Thirst
• Dysphagia (difficulty in swallowing)
• Dilated pupils
• Tachycardia
• Delirium
• Urinary urgency and retention
• Hallucinations
• Respiratory failure
• Hypertension (less marked than with sympathomi-
metic)
1. A mnemonic exists to help remember these symp-
toms in the form of a frase: red as a beet, dry as a bone,
mad as a hatter, hot as stone, bowel and bladder lose
their tone, and the heart runs alone.
A list of toxins which can cause this toxidrome inclu-
des:
• Belladonna alkaloids
• Certain species of mushrooms
• Jimson weed
• Scopolamine
• Antihistamines
• Tricyclic antidepressants
• Phenothiazines
• Over-the-counter sleep medications
D. Narcotic Toxidrome
The Narcotic Toxidrome is characterised by the foll-
owing:
• CNS depression
• Hypoventilation
• Hypotension
• Miosis (constricted pupils)
Causes include:
• Codeine
• Diphenoxylate (Lomotil)
• Heroin
• Propoxyphene (Darvon)
• Pentazocine (Talwin)
LÆKNANEMINN
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2. tbl. 1996, 49. árg.