Central nervous system toxicity may be manifest by initial excitability, generalized and prolonged convulsions which may be followed by respiratory depression, circulatory collapse, and death within a few hours. Neurological symptoms appear rapidly (30minutes to 2hours after drug ingestion), suggesting that in gross overdosage pyrimethamine has a direct toxic effect on the central nervous system. The fatal dose is variable, with the smallest reported fatal single dose being 375mg. There are, however, reports of pediatric patients who have recovered after taking 375 to 625mg. There is no specific antidote to acute pyrimethamine poisoning. In the event of overdosage, symptomatic and supportive measures should be employed. no dataGastric lavage is recommended and is effective if carried out very soon after drug ingestion. http://www.chinadragontour.com/laylamitchellshare/2017/01/03/gop-occurs-in-some-infants-who-are-born-prematurely-or-at-a-low-birth-weight/Parenteral diazepam may be used to control convulsions. Folinic acid should be administered within 2hours of drug ingestion to be most effective in counteracting the effects on the hematopoietic system (see WARNINGS ). Due to the long half-life of pyrimethamine, daily monitoring of peripheral blood counts is recommended for up to several weeks after the overdose until normal hematologic values are restored. DOSAGE AND ADMINISTRATION For Treatment of Toxoplasmosis: The dosage of DARAPRIM for the treatment of toxoplasmosis must be carefully adjusted so as to provide maximum therapeutic effect and a minimum of side effects.
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