Pyridostigmine
Brand Name(s): Mestinon®, Mestinon® Syrup, Mestinon® Timespan®; also available generically
WHY is this medicine prescribed?
Pyridostigmine is used to decrease muscle weakness resulting from myasthenia gravis.
HOW should this medicine be used?
Pyridostigmine comes as a regular tablet, an extended-release (long-acting) tablet, and a syrup to take by mouth. It usually is taken once, twice, or several times a day, depending on the type of tablet. Your doctor may change your dose, depending on how you respond to the drug. When you first start taking pyridostigmine, your doctor may want you to keep a daily record of the time you take each dose, how long you feel better after taking each dose, and if you have side effects. This record will help the doctor decide how much drug is best for you. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take pyridostigmine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Swallow the extended-release tablets whole; do not chew or crush them.
Continue to take pyridostigmine even if you feel well. Do not stop taking pyridostigmine without talking to your doctor.
Pyridostigmine overdose can cause severe illness, including muscle weakness. It is very hard to tell the difference between too little and too much pyridostigmine. Call your doctor immediately if your symptoms become worse.
Are there OTHER USES for this medicine?
This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.
What SPECIAL PRECAUTIONS should I follow?
Before taking pyridostigmine,
- tell your doctor and pharmacist if you are allergic to pyridostigmine, bromides, any other medications, or any of the ingredients in pyridostigmine preparations. Ask your pharmacist or check the patient information for a list of the ingredients.
- tell your doctor and pharmacist what prescription and nonprescription medications you are taking, especially allergy or cold medications, dexamethasone (Decadron), hydrocortisone (Hydrocortone), magnesium-containing products, medications for heart arrhythmias, sleeping pills, and vitamins.
- tell your doctor if you have or have ever had intestinal or bladder blockage, asthma, seizures, heart or kidney disease, thyroid problems, or stomach ulcers.
- tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking pyridostigmine, call your doctor.
- you should know that this drug may make you drowsy. Do not drive a car or operate machinery until you know how this drug affects you.
- remember that alcohol can add to the drowsiness caused by this drug.
What SPECIAL DIETARY instructions should I follow?
Pyridostigmine may cause an upset stomach. Take pyridostigmine with food or milk.
What should I do IF I FORGET to take a dose?
Take the missed dose as soon as you remember it. However, if you remember a missed dose near the time you are supposed to take the next dose, take only the regularly scheduled dose. Do not take a double dose to make up for a missed one.
What SIDE EFFECTS can this medicine cause?
Pyridostigmine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- upset stomach
- diarrhea
- vomiting
- drooling
- pale skin
- cold sweats
- blurred vision
- watery eyes
- increased urge to urinate
- anxiousness and feelings of panic
- muscle weakness
- severe itching, skin rash, or hives
- slurred speech
- confusion
- seizures
- difficulty breathing
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).
What should I know about STORAGE and DISPOSAL of this medication?
Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).
It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org
Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.
What should I do in case of OVERDOSE?
In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.
What OTHER INFORMATION should I know?
Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your response to pyridostigmine.
Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.
This report on medications is for your information only, and is not considered individual patient advice. Because of the changing nature of drug information, please consult your physician or pharmacist about specific clinical use.
The American Society of Health-System Pharmacists, Inc. represents that the information provided hereunder was formulated with a reasonable standard of care, and in conformity with professional standards in the field. The American Society of Health-System Pharmacists, Inc. makes no representations or warranties, express or implied, including, but not limited to, any implied warranty of merchantability and/or fitness for a particular purpose, with respect to such information and specifically disclaims all such warranties. Users are advised that decisions regarding drug therapy are complex medical decisions requiring the independent, informed decision of an appropriate health care professional, and the information is provided for informational purposes only. The entire monograph for a drug should be reviewed for a thorough understanding of the drug's actions, uses and side effects. The American Society of Health-System Pharmacists, Inc. does not endorse or recommend the use of any drug. The information is not a substitute for medical care.
AHFS® Patient Medication Information™. © Copyright, 2024. The American Society of Health-System Pharmacists®, 4500 East-West Highway, Suite 900, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.
Selected Revisions: March 15, 2020.