The optimal dose and timing of administration of anticholinesterase drugs must be determined empirically for each individual. A beneficial affect is dose dependent.

Pyridostigmine Bromide (peer-id-oh-STIG-meen) [Mestinon, Regonol], given orally, is the most widely used anticholinesterase agent for the treatment of myasthenia gravis. It is given alone for mild muscle weakness, or in combination with corticosteroids for moderate to severe impairment. Dosage requirements vary among patients because of differences in absorption , metabolism, and excretion of the drug. Therefore, the dosage and timing of administration must be determined empirically.

Other anticholinesterase agents include ambenonium (am-be-NOE nee-um) chloride [Mytelase] and Neostigmine (nee-oh-STIG-meen) Bromide, Neostigmine Methylsulfate [Prostigmin].

All of the anticholinesterase agents are given by mouth or by injection. Before the myasthenic patient begins the use of any of these drugs, the risks of taking the medicine must be weighed against the good it will do. This decision is made by the patient and their doctor, prior to which the following must be considered:

Allergies- any previous unusual or allergic reaction to ambenonium, bromides, neostigmine, or pyridostigmine as well as allergies to other substances such as foods, preservatives or dyes must be brought to the doctorís attention.

Pregnancy- although these drugs have not been reported to cause birth defects muscle weakness has occurred temporarily in some newborn babies whose mothers took anticholinesterase agents during pregnancy, thus this factor must be taken into consideration.

Breast-feeding- thusfar anticholinesterase agents have not been reported to cause problems in nursing babies.

Age- these medicines are not expected to cause different side effects or problems in children than they do in adults, nor are they expected to cause different side effects or problems in older people than the do in younger people, however there is no specific information comparing the use of anticholinesterase agents among various age groups.

Concurrent use of Other Medications- inform your doctor if you are using any of the following:
1. Echothiophate
2. Demecarium
3. Isofluropohote
4. Malathion: combination of these medicines with anticholinesterase agents may result in SERIOUS side effects.
5. Guanadrel
6. Guanethidine
7. Mecamylamine
8. Procainamide
9. Trimethaphan: the effects of these medicines may interfere with the actions of the anticholinesterase agents.


Other medical problems- may affect the use of the anticholinesterase agent.
10. Intestinal blockage
11. Urinary tract blockage
12. Urinary tract infection


Side Effects- the most common adverse reactions to anticholinesterase agents are caused by excessive cholinergic stimulation and include both muscarinic and nicotinic effects.

Symptoms of overdose:
blurred vision; clumsiness or unsteadiness; confusion; convulsions (seizures); diarrhea (severe); increase in bronchial secretions or watering of mouth (excessive); increasing muscle weakness (especially in the arms, neck, shoulders, and tongue); muscle cramps or twitching, nausea or vomiting (severe); shortness of breath, troubled breathing, wheezing, or tightness in chest; unusual irritability, nervousness, restlessness, or fear; unusual tiredness or weakness.

Rare symptoms:
redness, swelling, or pain at place of injection (for pyridostigmine injections only); skin rash (does not apply to ambenonium)


Other side effects may occur that usually do not need medical attention because they usually subside further into the treatment as the body adjusts to the medicine. However, if the following symptoms are found to persist, the doctor must be informed.

More common symptoms:
diarrhea; increased sweating; increased watering of mouth; nausea or vomiting; stomach cramps or pain; frequent urge to urinate; increase of in bronchial secretions; unusually small pupils; unusual watering of eyes