Bacterial endocarditis in a patient with idiopathic hypertrophic subaortic stenosis

A rare case of subacute bacterial endocarditis, due to a streptococcus viridans organism, is reported in a patient with idiopathic hypertrophic subaortic stenosis (IHSS). Subacute bacterial endocarditis prophylaxis is recommended for patients with IHSS.

Poisoning with organophosphorus insecticides

Because of an increasing incidence of poisoning with the newer organophosphorus anticholinesterase insecticides, these compounds have been reviewed in terms of their history and pharmacology, relationship with other drugs, factors affecting toxicity, mechanism of action, toxic signs and treatment. The modern organophosphorus pesticide requires metabolic conversion before toxicity develops. Insects have a greater propensity for this conversion than humans. Nevertheless, this conversion does occur in humans and can be potentiated by other drugs. Toxicity also varies with age, sex, route and frequency of administration, and previous exposure. The mechanism of toxicity is inhibition of acetylcholinesterase, causing an intoxicating build-up of acetylcholine. Signs and symptoms consist of the clinical manifestations of unopposed parasympathetic and central activity. Treatment must be initiated early. Respiration must be maintained and the effects of acetylcholine must be counteracted by massive doses of atropine. Metaraminol enhances the antagonistic action of atropine against acetylcholine and may also be given. Once acetylcholinesterase is inactivated, restoration is slow. Recovery can be accelerated by enzyme reactivators like the oxime compounds. Pyridine aldoxime (Pralidoxime, Protopam, P(2)S and 2-PAM) can be given in combination with atropine and metaraminol (AMP therapy) and may be the treatment of choice.

Effects of a combination of atropine, metaraminol and pyridine aldoxime methanesulfonate (AMP therapy) on normal human subjects

Four hundred and seventeen medical students at the University of Toronto were used as both subjects and observers in a series of double-blind experiments to determine possible toxic effects following oral ingestion of various combinations of 2 mg. atropine, 10 mg. metaraminol and 1 g. pyridine aldoxime methanesulfonate (P(2)S). Heart rate, blood pressure, pupil diameter, and visual accommodation were measured before and at 20-minute intervals after drug administration for 100 minutes. A visual and memory perceptual test (Mackworth) was performed before and 100 minutes after drug ingestion.No toxic effects were observed following administration of the triple combination of atropine, metaraminol and P(2)S (AMP therapy). The AMP combination might be useful prophylactically for persons facing exposure to organophosphorus anticholinesterase compounds. It must not be considered an adequate substitute for treatment should poisoning occur.