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A WILSON

Publications and source records attributed to A WILSON.

At least 19 recordsLinked to original sources

Determination of neostigmine and pyridostigmine in the urine of patients with myasthenia gravis.

A method has been described for the estimation of neostigmine and pyridostigmine in urine by ion exchange treatment and colorimetric estimation of the blue complex produced when either of the drugs is made to react with bromophenol blue. Urine containing 2 mug/ml. or more of neostigmine or 3 mug/ml. or more of pyridostigmine can be quantitatively estimated. After intramuscular injection of neostigmine to patients with myasthenia gravis, up to 67% of the drug is excreted, whilst after oral administration less than 5% is excreted. When pyridostigmine is given by mouth, the amount of drug excreted in the urine varies between approximately 2 and 16%. It has been established by chromatographic analysis that the blue complexes formed under these conditions are due only to neostigmine and pyridostigmine respectively and that the quantitative estimation described is a true measure of the amount of these drugs excreted in the urine. The significance of these results is discussed in relation to the absorption and metabolism of the two drugs.

Administration, Oral↗

Hydrolysis of neostigmine by plasma cholinesterase.

Incubation of neostigmine with normal human plasma in vitro results in the formation of two quaternary nitrogen compounds, one of which has been identified as m-hydroxyphenyltrimethylammonium. This hydrolysis is prevented by prior addition of dyflos to plasma in concentrations sufficient to inhibit plasma cholinesterase activity. The significance of these findings is discussed in relation to the occurrence of the same metabolic products in the urine of patients with myasthenia gravis treated with oral neostigmine. No equivalent findings are available for normal subjects since it was not considered justifiable to treat them with neostigmine.

Ammonium Compounds↗