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Plasma Pyridostigmine Levels in Patients with Myasthenis Gravis
Clinical Pharmacology and Therapeutics (1977)
  • Kelvin Chan

Plasma concentrations of pyridostigmine were measured in 7 patients with myasthenia gravis. Six subjects on oral pyridostigmine bromide were stabilized on widely different doses of the drug (60 to 660 mg/day). Nevertheless, the concentration of the quaternary amine in plasma was maintained within a relatively narrow range (usually between 20 and 60 ng/ml). In 3 myasthenic patients, the area under the plasma concentration-time curve was relatively constant for 4 hr after the same oral dose of pyridostigmine (60 mg). Despite this similarity, there were in general considerable interindividual differences in teh bioavailability of pyridostigmine in myasthenic patients. In 1 subject, the bioavailability of the quaternary amine was increased sixfold by doubling the oral dose from 30mg to 60 mg. After oral administration of pyridostigmine, the half-life of the drug in one subject (4.25 hr) was almost three times as great as after intramuscular administration in a different patient (1.49 hr).

  • Pyridostigmine,
  • plasma concentration,
  • plasma levels,
  • myasthenia gravis
Publication Date
Citation Information
Kelvin Chan. "Plasma Pyridostigmine Levels in Patients with Myasthenis Gravis" Clinical Pharmacology and Therapeutics Vol. 21 Iss. 2 (1977)
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