Mestinon is a common treatment for myasthenia gravis but 25% of all patients who take it discontinue it because of side effects, and many discontinue it because it does not make any difference to their symptoms. Because it is short-acting, it could theoretically be stopped without tapering it, but you should always talk to your doctor about stopping it before you do so.

Side effects such as diarrhea, flatulence, urinary urgency, muscle cramps, blurred vision, and increased sweating are the most common reason for stopping Mestinon. Some people stop it because it does not work for them, and this may be because their Myasthenia Gravis (MG) may be in remission or under control.

Because Mestinon only helps with symptom relief and does not change the course of the condition, it is not necessary to take it all the time if it does not appear to be providing benefit. Some people may benefit from an increase in dose, although this is likely to increase their risk of side effects, including muscle cramping, excessive saliva or secretions in the throat, runny eyes and nose, abdominal pain, or diarrhea.

The overall benefit and effectiveness of Mestinon have been described as moderate and it may be helpful to skip a dose to see if there is any effect. Usually, the effects of Mestinon take 30 to 40 minutes to be noticeable and it only lasts for 3 to 6 hours, which is why it needs to be taken 4 to 5 times a day for a lasting effect. Talk to your doctor if you do not feel that Mestinon is benefiting you.

Mestinon works by slowing the breakdown of the chemical messenger acetylcholine at the neuromuscular junction. This action helps to improve muscle strength by increasing the signals between nerves and muscles. Mestinon is a prescription medication used in the treatment of myasthenia gravis, a neuromuscular disease.

Mestinon has also been used to reduce a fast heart rate (tachycardia) in people with postural orthostatic tachycardia syndrome (POTS) (see here for more information) although it does not appear to offer any more benefit than beta-blockers alone.