Medication Summary
Activated charcoal is indicated for all tropane alkaloid poisonings, within an hour of ingestion, with the possible exception of poisoning from smoking leaves. Benzodiazepines are first-line agents for agitation and seizures. Physostigmine should be used only for life-threatening complications.
GI decontaminant
Class Summary
Activated charcoal is used after a drug or plant ingestion to limit adsorption of toxins. Traditionally given after the stomach has been emptied by emesis or lavage, recent evidence indicates that it may be used alone, without lavage.
Activated charcoal (Liqui-Char)
Emergency treatment in poisoning caused by drugs and chemicals. Network of pores present in activated charcoal adsorbs 100-1000 mg of drug per gram of charcoal. An extremely important component of tropane alkaloid poisoning. May decrease severity and duration of poisoning. Does not dissolve in water.
For maximum effect, administer within 30 min after ingesting poison.
Benzodiazepines
Class Summary
First-line agents for treatment of tropane-alkaloid-induced seizures. Lorazepam is thought to be most effective and has a longer seizure half-life than diazepam.
Lorazepam (Ativan)
Sedative hypnotic with short onset of effects and relatively long half-life. DOC if IV access is available.
Increasing the action of gamma-aminobutyric acid (GABA), which is a major inhibitory neurotransmitter in the brain, may depress all levels of CNS, including limbic and reticular formation.
Monitoring patient's blood pressure after administering dose is important. Adjust prn.
Midazolam (Versed)
Used as alternative in termination of refractory status epilepticus. Because midazolam is water soluble, it takes approximately 3 times longer than diazepam to peak EEG effects. Thus clinician must wait 2-3 min to fully evaluate sedative effects before initiating procedure or repeating dose. Published reports of IM and anecdotal reports of nasal use exist (when IV access is not possible).
Diazepam (Valium)
Depresses all levels of CNS (eg, limbic and reticular formation), possibly by increasing activity of GABA. Frequently used in prehospital systems since refrigeration is not required.
Cholinergic agents
Class Summary
Physostigmine is indicated only for reversal of life-threatening complications of tropane alkaloid poisoning (eg, tachydysrhythmias with hemodynamic compromise, seizures refractory to other therapeutic interventions, and severe agitation or hallucinations unresponsive to other therapy). The decision to use physostigmine ideally should be made in consultation with a toxicologist or poison control center.
Physostigmine (Antilirium)
Reversible anticholinesterase inhibitor that increases the concentration of acetylcholine at cholinergic synapses. The only reversible anticholinesterase inhibitor that readily crosses the blood-brain barrier to produce the desired CNS effects. Some recommend repeated slow IV pushes of 0.1-0.3 mg q3min to a maximum of 2 mg to decrease potential for life-threatening cardiovascular adverse effects.
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Datura stramonium (jimson weed). Note 4-5 inch long white flowers.© 2000 Richard Wagner
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Datura stramonium flower. Note the trumpetlike shape.© 2000 Richard Wagner
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Datura stramonium (close-up of unripe seed pods). Note spiny appearance of pods.© 2000 Richard Wagner
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Datura stramonium is the plant shown. © 2000 Richard Wagner
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The plant shown is foxglove (Digitalis purpura), which contains cardiac glycosides, not tropane alkaloids. © 2000 Richard Wagner