Pyridostigmine (Mestinon) is a cholinesterase inhibitor that's commonly used for treating muscle weakness due to myasthenia gravis in adults. It works by improving the communication between the muscles and nerves. This medication is available as a tablet and liquid that are taken by mouth multiple times per day. Side effects aren't common, but taking too much can cause stomach upset, too much saliva, and muscle problems.
Pyridostigmine (Mestinon) is a cholinesterase inhibitor. It blocks a protein called cholinesterase from breaking down acetylcholine, a chemical in your body that's important for communication between your nerve cells and muscles. As a result, pyridostigmine (Mestinon) helps more acetylcholine stay in your body to activate your muscles. This helps lessen muscle weakness.
Source:Â DailyMed
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
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
slow heartbeat
slurred speech
stomach cramps or pain (severe)
unusual irritability, nervousness, restlessness, or fear
unusual tiredness or weakness
Check with your doctor as soon as possible if any of the following side effects occur:
Rare
Redness, swelling, or pain at place of injection (for pyridostigmine injection only)
skin rash (does not apply to ambenonium)
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
Less common
Frequent urge to urinate
increase in bronchial secretions
unusually small pupils
unusual watering of eyes
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
First-choice treatment for myasthenia gravis
Available as an oral solution if you need small dose changes or have trouble swallowing pills
Available as a lower-cost generic form
Doesn't cure myasthenia gravis
Might need to take multiple times a day (especially for immediate-release tablets and oral solution)
Can't use if you have urinary or intestinal blockage
You can take pyridostigmine (Mestinon) with or without food. If it upsets your stomach, try taking it with food to help.
For the extended-release tablet: Swallow the extended-release tablet whole. Don't chew, break, or crush the medication. You might also need to take the faster-acting, immediate-release tablet or oral solution to help provide enough symptom relief throughout the day.
Contact your provider if you can't take your usual dose of pyridostigmine (Mestinon) because of any vomiting or because you're having trouble swallowing. Also, seek medical help right away if you become severely weak, especially if it starts getting hard to breathe.
Don't stop taking pyridostigmine (Mestinon) unless your provider told you to do so. Pyridostigmine (Mestinon) is usually a much-needed medication for people with myasthenia gravis. You can have serious muscle weakness if you stop taking it or skip too many doses.
Talk to your provider if you become pregnant during treatment with pyridostigmine (Mestinon). There isn't enough information to know whether this medication is safe during pregnancy or while you're breastfeeding.
More tips for pyridostigmine (Mestinon) liquid:
Store the medication bottle at room temperature.
Make sure to only use a medication dose cup or oral syringe from the pharmacy to measure out your dose. Don't use household spoons because they aren't accurate and might cause you to take the wrong dose.
The pyridostigmine (Mestinon) liquid contains 5% alcohol. Talk to your provider if this concerns you.
Pyridostigmine (Mestinon) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Taking too much pyridostigmine (Mestinon) can cause muscle weakness. However, muscle weakness is also a sign of worsening myasthenia gravis. It can be hard to tell whether you're taking too much or too little pyridostigmine (Mestinon). Yet, both situations are potentially life-threatening if your lungs become too weak to breathe. Keep in mind that myasthenic crisis can happen when your muscles feel severely weak, even though you've been taking pyridostigmine (Mestinon) as prescribed.
Call your provider right away if you have any muscle weakness to figure out whether you need to take less or more of pyridostigmine (Mestinon). Your provider can help identify the cause of your muscle weakness and treat the symptoms. Seek medical attention right away if you become severely weak or have trouble breathing.
Muscle weakness can be a sign of worsening myasthenia gravis or a sign that you've taken too much pyridostigmine (Mestinon). Muscle weakness can be dangerous if it makes your lungs too weak to breathe. For this reason, pyridostigmine (Mestinon) should be used with caution in people with asthma. Tell your provider if you have any lung or breathing problems before you start pyridostigmine (Mestinon). Get medical help right away if you have trouble breathing while you're taking this medication.
Immediate-release tablets and 60 mg/5 mL oral solution (liquid): The typical dose is 600 mg by mouth per day. People with mild myasthenia gravis might only need 60 mg to 360 mg per day. But those with more severe myasthenia gravis might need up to 1,500 mg per day. Your provider will help you space out your total dose throughout the day.
Extended-release tablets: The typical dose is 180 mg to 540 mg by mouth once or twice daily. The doses should be separated by at least 6 hours.
Your provider will adjust your dose based on how well it's helping your condition, whether you have kidney problems, and whether you're having side effects.
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking any of these medicines, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using medicines in this class with any of the following medicines is not recommended. Your doctor may decide not to treat you with a medication in this class or change some of the other medicines you take.
Using medicines in this class with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Intestinal or urinary blockage
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