Mestinon is a brand-name drug that’s prescribed for myasthenia gravis. The medication is available in the following forms: oral solution, oral tablet, and extended-release oral tablet.
You’ll find key information about Mestinon below.
- Drug class: cholinesterase inhibitor
- Drug forms: oral solution, oral tablet, and an extended-release* oral tablet
- Generic available? yes
- Prescription required? yes
- Controlled substance? no
- Year of FDA approval: 1955
Note: Unless the drug form is noted, “Mestinon” in this article refers to any of the drug forms.
* Extended release means the drug is slowly released into your body over a period of time.
Mestinon is a brand-name drug that contains the active drug pyridostigmine. This active drug is also available as a generic medication. A generic drug is an exact copy of the active drug in a brand-name medication.
The generic is considered to be as safe and effective as the original drug. Generics tend to cost less than brand-name drugs.
If you’re interested in taking the generic form of Mestinon, talk with your doctor. They can tell you whether it comes in forms and strengths that can be prescribed for your condition.
Mestinon can cause mild or serious side effects. The following lists contain some of the key side effects that may occur while taking Mestinon. These lists do not include all possible side effects.
For more information about the possible side effects of Mestinon, talk with your doctor or pharmacist. They can give you tips on how to manage any side effects that may be concerning or bothersome.
Note: The Food and Drug Administration (FDA) tracks side effects of drugs it has approved. If you would like to notify the FDA about a side effect you’ve had with Mestinon, you can do so through MedWatch.
Mild side effects
Below is a partial list of mild side effects of Mestinon. To learn about other mild side effects, talk with your doctor or pharmacist, or view Mestinon’s prescribing information.
Mild side effects of Mestinon can include:
- digestive side effects, such as:
- nausea, vomiting, and diarrhea
- abdominal cramps
- increased saliva and mucus
- symptoms of increased peristalsis (wave-like muscle contractions that move food through your digestive system), such as:
- sweating more than is typical
- pinpoint pupils
- muscle cramping or twitching
- muscle weakness
- blurred vision
- needing to urinate more often than is typical
- skin rash
- mild allergic reaction*
Most of these side effects may go away within a few days to a couple of weeks. However, if they become more severe or don’t go away, talk with your doctor or pharmacist.
* For more information about allergic reaction and Mestinon, see “Allergic reaction” below.
Serious side effects
Serious side effects from Mestinon aren’t common, but they can occur. Call your doctor right away if you have serious side effects. Call 911 or your local emergency number if your symptoms feel life threatening or if you think you’re having a medical emergency.
Serious side effects and their symptoms can include:
- Cholinergic crisis (a condition caused by too much Mestinon in the body). Symptoms can include:*
- worsening muscle weakness
- difficulty breathing due to weakening of muscles involved in breathing
- Slowed heart rate or heart block. Symptoms may include:
- Syncope (fainting).
- Changes in mood or behavior, such as:
- hallucinations (perceiving the presence of people or objects that aren’t real)
- Severe allergic reaction.†
* Symptoms of cholinergic crisis may be difficult to distinguish from worsening myasthenia gravis. For more information, talk with your doctor.
† For details about allergic reaction and Mestinon, see “Allergic reaction” below.
As with most drugs, some people can have an allergic reaction after taking Mestinon. It isn’t known whether allergic reactions occurred clinical trials of this drug or how often they may have happened.
Symptoms of a mild allergic reaction can include:
A more severe allergic reaction is rare but possible. Symptoms of a severe allergic reaction can include:
- swelling under your skin, typically in your eyelids, lips, hands, or feet
- swelling of your tongue, mouth, or throat
- trouble breathing
Call your doctor right away if you have an allergic reaction to Mestinon, as the reaction could become severe. Call 911 or your local emergency number if your symptoms feel life threatening or if you think you’re having a medical emergency.
Here are answers to some frequently asked questions about Mestinon.
Can Mestinon be taken for POTS, orthostatic hypotension, or gastroparesis?
It’s possible. Doctors may prescribe Mestinon off-label* for conditions such as:
- postural orthostatic tachycardia syndrome (POTS), a sudden increase in heart rate when you stand up that often causes dizziness
- orthostatic hypotension, a drop in blood pressure when you stand or sit up that may cause dizziness
- gastroparesis, a slower-than-typical emptying of stomach contents into your intestines
Talk with your doctor for more information about off-label uses of Mestinon.
* Off-label use is when a drug is prescribed for a purpose other than its approved use. Mestinon is approved to treat myasthenia gravis in adults.
Does Mestinon cause long-term side effects?
Mestinon isn’t known to cause any long-term side effects. To learn about side effects of Mestinon, see the “Mestinon side effects” section above.
If you have questions about your risk of side effects with Mestinon, talk with your doctor.
Is withdrawal possible with Mestinon?
No, withdrawal symptoms haven’t been reported with Mestinon. These are uncomfortable side effects that can occur when you stop taking a drug your body is used to. However, stopping Mestinon may cause symptoms of myasthenia gravis to return or worsen.
You should not pause or stop Mestinon treatment unless you have discussed it with your doctor. Talk with your doctor or pharmacist if you have questions about stopping treatment with Mestinon.
The Food and Drug Administration (FDA) approves prescription drugs such as Mestinon to treat certain conditions. Mestinon may also be used off-label for other conditions. Off-label drug use is when an FDA-approved drug is prescribed for a purpose other than what it’s approved for.
Mestinon for myasthenia gravis
Mestinon is FDA-approved to treat myasthenia gravis in adults.
Myasthenia gravis is a neuromuscular condition (a disease affecting nerves and muscles). It causes muscle weakness in the arms, legs, face, and other body areas. This muscle weakness may also affect the muscles involved in breathing. This can lead to difficulty breathing or worsen existing breathing problems you may have.
Mestinon and children
Mestinon is FDA-approved to treat myasthenia gravis in adults. It isn’t approved for use in people younger than 18 years of age.
The Mestinon dosage your doctor prescribes will depend on several factors. These include:
- the severity of the condition you’re taking Mestinon to treat
- the form of Mestinon you take
- other medical conditions you may have, such as kidney disease
The following information describes dosages that are commonly prescribed or recommended. However, be sure to take the dosage your doctor prescribes for you. Your doctor will determine the best dosage to fit your needs.
Drug forms and strengths
Mestinon is available in three oral forms that you swallow. They come in the following strengths:
- solution: 60 milligrams in 5 milliliters (60 mg/5 mL) of solution
- tablet: 60 mg
- extended-release (ER)* tablet: 180 mg
* With extended release, the drug releases slowly into your body over a period of time.
Dosage for myasthenia gravis
The dosage of Mestinon for myasthenia gravis depends on your individual needs. Your doctor will adjust your dosage to determine the amount that relieves your symptoms.
Mestinon tablet and solution. The average dose for Mestinon tablet and solution is 600 mg. You’ll take your prescribed dose as several smaller doses throughout the day. Your doctor will prescribe a dosing schedule that will work best for you.
An example dosing schedule for a 600-mg daily dose is:
- one 60-mg tablet every 6 hours, or
- 5 mL (one teaspoon [tsp]) of 60 mg/5 mL solution every 3 hours
Mestinon ER tablet. The average dose for Mestinon ER tablet is 180–540 mg (one to three 180-mg ER tablets). Your doctor may have you take one to two doses per day based on the severity of your condition.
The maximum dosage of any form of Mestinon is 1,500 mg per day.
Note: In some cases, doctors prescribe more than one form of Mestinon. For example, some people have weakness of the muscles involved in swallowing. But they may only experience this symptom in the morning. In general, solutions are easier to swallow than tablets. Their doctor may prescribe Mestinon solution for the morning dose and a tablet form for later doses.
About taking Mestinon
Below you’ll find information about key dosage issues.
- When to take. You should take Mestinon according to your doctor’s directions. If you take Mestinon ER tablets, be sure to space your doses at least 6 hours apart.
- If you miss a dose. If you miss a dose, ask your doctor or pharmacist for advice. Mestinon’s manufacturer hasn’t provided guidance on what to do if you miss a dose.
- Taking Mestinon with food. Mestinon may be taken with or without food. For many drugs, taking your dose with food can help prevent or lessen digestive side effects. For a list of side effects, see the “Mestinon side effects” section above.
- Crushing, splitting, or chewing Mestinon. Mestinon’s manufacturer hasn’t provided guidance on crushing, splitting, or chewing Mestinon tablets. However, Mestinon tablets and ER tablets are scored (have a line down the middle). Scored tablets are generally safe to cut or split. If you have trouble swallowing tablets, talk with your doctor. They may prescribe Mestinon solution instead.
- Length of treatment. Mestinon is meant to be a long-term treatment. If you and your doctor determine that Mestinon is safe and effective for you, you’ll likely take it long term.
- Length of time to work. Mestinon starts working within 15–30 minutes of taking a dose. However, it may take several days or weeks before you notice a difference in your symptoms. During this time, your doctor will determine the drug form and dosing schedule that’s effective for your condition.
Do not take more Mestinon than your doctor recommends. For some drugs, doing so may lead to unwanted side effects or overdose.
What to do in case you take too much Mestinon
If you think you’ve taken too much of this drug, call your doctor. You can also call America’s Poison Centers at 800-222-1222 or use its online tool. However, if your symptoms are severe, call 911 or your local emergency number, or go to the nearest emergency room right away.
As with all medications, the cost of Mestinon can vary. The actual price you’ll pay depends on your insurance plan, your location, and the pharmacy you use.
Drug coupons. You can visit Optum Perks* for price estimates of Mestinon. These estimates are based on the use of Optum Perks coupons. Note: Optum Perks coupons cannot be used with any insurance copays or benefits.
Financial and insurance assistance. If you need financial support to pay for Mestinon, or if you need help understanding your insurance coverage, help is available.
To learn more about saving money on prescriptions, check out this article.
Generic version. Mestinon is available in a generic form called pyridostigmine. A generic drug is an exact copy of the active drug in a brand-name medication. The generic is considered to be as safe and effective as the original drug. And generics tend to cost less than brand-name drugs. To find out how the costs of pyridostigmine and Mestinon compare, talk with your doctor or pharmacist.
* Optum Perks is a sister site of Medical News Today.
If you can become pregnant, consider the following information about pregnancy and breastfeeding.
Mestinon and pregnancy
It’s not known whether Mestinon is safe to take during pregnancy. If you’re planning a pregnancy or can become pregnant, talk with your doctor before taking this medication.
If you or your partner can become pregnant, talk with your doctor about your birth control needs during Mestinon treatment.
Mestinon and breastfeeding
It’s not known whether Mestinon is safe to take while breastfeeding. If you’re currently breastfeeding or planning to do so, talk with your doctor before taking this medication.
Mestinon may interact with other medications. It isn’t known whether Mestinon may interact with supplements or foods.
Before taking Mestinon, talk with your doctor and pharmacist. Tell them about all prescription, over-the-counter, and other drugs you take. Also, tell them about any vitamins, herbs, and supplements you use. Sharing this information can help you avoid potential interactions.
Interactions with medications
Below is a list of medications that can interact with Mestinon:
- atropine, an anticholinergic drug
- corticosteroids such as prednisone (Rayos) and methylprednisolone (Medrol)
Note: The list above does not contain all drugs that may interact with Mestinon. If you have questions about drug interactions that may affect you, ask your doctor or pharmacist.
Alcohol is not known to interact with Mestinon.
If you have questions about how much alcohol is safe to drink while taking Mestinon, talk with your doctor or pharmacist.
Other drugs are available that can treat your condition. Some may be a better fit for you than others. If you’re interested in finding an alternative to Mestinon, talk with your doctor. They can tell you about other medications that may work well for you.
The following drugs may be prescribed to treat myasthenia gravis:
This drug comes with several precautions.
Before taking Mestinon, discuss your health history with your doctor. Mestinon may not be right for you if you have certain medical conditions or other factors affecting your health. Be sure to talk with your doctor if any of the following apply to you:
- blockage of the intestine or bladder
- kidney problems such as chronic kidney disease
- past allergic reaction* to Mestinon or a similar drug
Note: For more information about the potential negative effects of Mestinon, see the “Mestinon side effects” section above.
* For details about this, see “Allergic reaction” in the “Mestinon side effects” section above.
† To learn more about pregnancy and breastfeeding, see the “Things to consider when taking Mestinon” section above.
Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.