Antidotes physostigmine

This may call for maintenance of fluid intake, and if a marked increase in temperature occurs, cooling is indicated. If there is continued mental aberration then the antidote physostigmine can be given as 2-3 mg IM for alleviation, followed by repeat injections at 15-60 min intervals to prevent relapse, and if required a slow i.v. infusion. The dose should be determined by the clinical condition of the subject. Another antidote is 7-methoxytocrine (7-MEOTA). For mild intoxication an oral dose of 100 mg can be given. For more severe poisoning, IM dosing (50 mg) is more effective. 

The antidote, physostigmine, can be used and is safe and effective if used properly. It is most effective after 4 hours from time of exposure, although effects from a single intramuscular injection of physostigmine last only about 60 minutes, requiring frequent re-dosing. Corrective resuscitative measures should take place primarily and it should not be used in a patient with cardiorespiratory compromise, hypoxia, or acid-base imbalance with a history of seizure disorders or arrhythmias. 

Pilocarpine is being less used in medicine as a diaphoretic in dropsy and similar diseases because of its depressant action on the heart. It has also been employed as a substitute for physostigmine to contract the pupil and reduce intraocular pressure. It has been used as an antidote to atropine, but it does not antagonise the action of atropine in the central nervous system. 

EA 3167 proved to be as potent as the most potent glycolates we had studied and its duration was much longer than any. One subject required antidote treatment for more than two weeks to stave off delirium. During that period, he received a total of 231 mg of physostigmine (a single dose would be 2-4 mg). 

Since we were on the hunt, we did read a few such books, discovering that we were not the first, by a long shot, to observe the effectiveness of physostigmine as a belladonnoid antidote. We also found several relevant articles, published a decade earlier in the American Journal of Psychiatry and several other reputable journals. They came from a relatively little known group of psychiatrists who were investigating a new form of therapy in their hospital. The story is somewhat convoluted, but nonetheless interesting. 

I can almost hear some of the musings of the unbelievers After all, this study was done by psychiatrists. Who knows, maybe they absent-mindedly moved the decimal points. In any case, the new treatment method did not make it into mainstream American psychiatry, much less general medical practice. Nor did the good news that physostigmine was an effective antidote for atropine delirium. (Incidentally, I met Forrer s colleague. Dr. Miller, in 1981, 30 years after their first publications about atropine coma therapy. He was invited to... 

T s accident occurred before we had fully established the effectiveness of physostigmine as an antidote, but we did have tetrahydroaminoacridine (TELA) and used it over several days to minimize his delirious behavior. We housed him in our newly constmcted padded ward, and watched him closely for two weeks as he gradually returned to an ostensibly normal mental state. I discussed the problem with Dr. Rioch at Walter Reed, who advised me to provide supportive counseling for as long as necessary to ensure full recovery. 

Nurses gave physostigmine intermittently to the two most affected volunteers. Whenever they withheld the antidote for more than two hours, scores predictably fell to the untreated level. These observations furthered our knowledge about the effectiveness and duration of physostigmine s actions. We had reached all our goals for the first field test without a glitch and on Saturday, we could release both the volunteers and the medical staff for the weekend. But on Monday, we had to be ready try the test at a 1,000 yards test with a second group of volunteers. 

When a casualty is safely evacuated to the treatment area, the medical staff will provide diagnosis and treatment with physostigmine, if indicated. If the antidote restores him to normal or near-normal function, he will return to his unit... 

Were we, indeed, supposed to be able to terminate the experiment at any stage by having an effective antidote at hand If so, many of the studies we did at Edgewood technically violated this rule. Not only was there nothing that could reverse the effects of LSD (there is still no true antidote today) but in 1960 and 1961 we also had no antidote for BZ. We did not recognize physostigmine s effectiveness until 1962. 

Nor were there effective antidotes to the cognitive effects of major tranquilizers such as Prolixin, or sedatives such as Seconal. I m not sure why the IG did not apply their criticism about the lack of an LSD antidote to our much more extensive work with belladonnoids. Until THA and physostigmine came along, I always knew, after giving BZ that I would have to let it run its course. Fortunately, there were no major crises. 

When George Aghajanian and Fred Sidell decided to investigate the usefulness of antidotes other than physostigmine, scopolamine became the belladonnoid of choice, since its duration of action was short and both nursing and volunteer time required to conduct treatment studies were limited to a single day of observations. 

Karger S. Incapacitating dose of CAR 302668 in man and efficacy of physostigmine as an antidote. Edgewood Arsenal Technical Memorandum 114-20, 1968... 

A number of drugs in addition to atropine and scopolamine have antimuscarinic properties. Tbese include tricyclic antidepressants, phenothiazines, and antihistamines. Physostigmine has been used in the treatment of acute toxicity produced by these compounds. However, physostigmine can produce cardiac arrhythmias and other serious toxic effects of its own, and therefore, it should be considered as an antidote only in life-threatening cases of anticholinergic drug overdose. 

Acute belladonna poisoning can be treated by administering universal antidote before gastric lavage, physostigmine in the dose of 1-A mg SC can be administered after a interval... 

The correct answer = A. Scopolamine has effects similar to those of atropine. Trimethaphan is a ganglionic blocker affecting nicotinic receptors atropine affects primarily muscarinic receptors. Physostigmine, an anticholinesterase drug, is the antidote for an excess of atropine. Atropine blocks the effects of acetylcholine and direct-acting agonists, such as carbachol. 

Today, physostigmine is used only rarely in medicine, as a miotic, which helps to reduce intra-ocular pressure in the glaucomic eye, and as an antidote following the intake of anticholinergic drugs (e.g., atropine and scopolamine). 

Neostigmine (= 3-Dimethyl-carbamoxyphenyl) trimethylammonium] (quaternary amine aryl carbamate) Synthetic - cf. Physostigmine AChE (carbamoylates - forms carbamoyl ester with active site Serine) [cholinergic, myotic, toxic (curare antidote)]... 

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