Physostigmine respiratory effects

Physostigmine (eserine sulfate) causes miosis and spasm of accommodation it also lowers intraocular pressure and hence can be used in the treatment of wide-angle glaucoma. As it is lipid soluble, it penetrates into the brain rapidly, raises the acetylcholine concentration and, in toxic amounts, may cause cholinergic CNS toxicity, which is characterized by restlessness, insomnia, tremors, confusion, ataxia, convulsions, respiratory depression, and circulatory collapse. These effects are reversed by atropine. 

The administration of morphine is followed by a series of complex events. Analgesia, euphoria, addiction, and respiratory depression are stressed in the literature, but if morphine had only its effect on carbohydrate metabolism it would rank wdth insulin and phloridzin in interest if it had only its effect on smooth muscle it would rank with pilocarpine and physostigmine and if it had only its effect on gastric secretion and salivation it wmuld rank with histamine. But consideration of some effects is lost in the importance of analgesia and only possible counter indications to its use as an analgesic remain continuously on the experimental horizon. 

Kim, Y.-B., Cheon, K.-C., Hu, G.-H., et al., 2002. Effects of combinational prophylactics composed of physostigmine and procyclidine on soman-induced lethality, seizures and brain injuries. Env. Toxicol. Pharmacol. 11, 15-21. Kubin, L., Fenik, V., 2004. Pontine cholinergic mechanisms and their impact on respiratory regulation. Resp. Physiol. Neurobiol. 143, 235-249. 

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