Displaying 2 results of Pyridostigmine Stable Isotopes Pyridostigmine is a medication used to treat myasthenia gravis, a neuromuscular disorder that causes muscle weakness and fatigue. Stable isotopes of pyridostigmine are used in medical research and drug development to study the pharmacokinetics and metabolism of the drug. These isotopes are chemically identical to the naturally occurring pyridostigmine, but have a different number of neutrons in the nucleus, making them useful for tracing the drug's movement through the body.