Scopolamine lethal dose

Based on pooled data, Goodman calculated that 450 mg is the average lethal dose (LD50), about forty-five times the dose that produces delirium. One report in the literature documents a case of recovery from an oral dose of 1,000 mg of atropine. Also, at least one individual has survived 500 mg (from 100 to 150 times the delirium-producing dose) of the related but more potent drug scopolamine... 

Goodman noted that the usual textbook estimates of the lethal dose of atropine (and scopolamine) are undoubtedly too low. With respect to scopolamine, for example, he found 9 cases that survived scopolamine doses of 225-267 mg, 3 cases that survived 324-384 mg and 2 who survived 500 mg.. (Abood also reported personal observation of two recoveries from large oral doses of scopolamine 350 mg and 500 mg, respectively.) These doses are close to the highest reported lethal range for atropine. Since scopolamine has about 7x the potency of atropine centrally, but roughly equal potency peripherally, one can infer that death from belladonnoid drugs is probably due to a peripheral effect - most likely cardiotoxicity. 

The naturally occurring drugs atropine and scopolamine have a different sort of antagonistic effect They block the muscarinic subtype of acetylcholine receptors. As a result, they impair our ability to form new memories and produce considerable mental confusion and drowsiness. At high doses, atropine and scopolamine can be lethal. 

Contraindications Extremely toxic. Even moderate doses could be fatal. Root contains apoatropine which can be lethal even in small amounts, especially when taken orally. Use not recommended. See ATROPINE and SCOPOLAMINE. 

Fatalities from intoxication with atropine and scopolamine are rare, but they sometimes occur in children, in whom 10 mg or less may be lethal. Idiosyncratic reactions are more common with scopolamine chan with atropine, and ordinary therapeutic doses sometimes cause alarming effects. Table 1 lists undesirable responses or symptoms of overdose associated with various doses of atropine. 

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