Pyridostigmine, Oral/Injection

What are other names for this medicine?

Type of medicine: cholinergic agonist; antimyasthenic

Generic and brand names: pyridostigmine, injection; pyridostigmine, oral; Mestinon; Mestinon; Mestinon Time-span; Regonol

What is this medicine used for?

This medicine is taken by mouth to treat myasthenia gravis, a disease that causes muscle weakness. It may be used for other conditions as determined by your healthcare provider.

This medicine may also be given by injection (shots). Your healthcare provider may give the injections to diagnose your condition or to evaluate treatment.

What should my healthcare provider know before I take this medicine?

Before taking this medicine, tell your healthcare provider if you have ever had:

• an allergic reaction to any medicine
• asthma
• heart problems such as an irregular or slow heartbeat
• seizures
• thyroid problems
• intestinal obstruction
• kidney disease
• Parkinson's disease
• ulcers
• trouble urinating

Females of childbearing age: Talk with your healthcare provider if you are pregnant or plan to become pregnant. Do not breast-feed while taking this medicine without your healthcare provider's approval.

How do I use it?

This medicine may come in different forms. If you have extended-release tablets, do not break, crush, or chew them. Swallow them whole. Ask your pharmacist if you have the extended-release tablets.

Check the label on the medicine for directions about your specific dose. Take this medicine exactly as your healthcare provider prescribes. Do not take more or less or take it longer than prescribed. Do not stop taking this medicine without your healthcare provider's approval.

You may take this medicine with or without food. Taking it with meals may lessen the chance the drug will upset your stomach.

If you are taking this medicine by mouth, your healthcare provider may want you to keep a record of each dose you take and how it affects you. This information helps your healthcare provider adjust your dosage to get the best results. Follow your healthcare provider's instructions.

What if I miss a dose?

If you miss a dose, take it as soon as you remember unless it is almost time for the next scheduled dose. In that case, skip the missed dose and take the next one as directed. Do not take double doses. If you are not sure of what to do if you miss a dose, or if you miss more than one dose, contact your healthcare provider.

What if I overdose?

If you or anyone else has intentionally taken too much of this medicine, call 911 or go to the emergency room right away. If you pass out, have seizures, weakness or confusion, or have trouble breathing, call 911. If you think that you or anyone else may have taken too much of this medicine, call the poison control center. Do this even if there are no signs of discomfort or poisoning. The poison control center number is 800-222-1222.

Symptoms of an acute overdose may include: extreme muscle weakness, nausea, vomiting, diarrhea, sweating, muscle cramps, weakness.

What should I watch out for?

This medicine may cause blurred vision, dizziness, or drowsiness. Do not drive or operate machinery unless you are fully alert and can see clearly.

If you need emergency care, surgery, or dental work, tell the healthcare provider or dentist you are taking this medicine.

What are the possible side effects?

Along with its needed effects, your medicine may cause some unwanted side effects. Some side effects may be very serious. Some side effects may go away as your body adjusts to the medicine. Tell your healthcare provider if you have any side effects that continue or get worse.

Life-threatening (Report these to your healthcare provider right away. If you cannot reach your healthcare provider right away, get emergency medical care or call 911 for help): Allergic reaction (hives; itching; rash; trouble breathing; tightness in your chest; swelling of your lips, tongue, and throat).

Serious (report these to your healthcare provider right away): Severe nausea, vomiting, diarrhea, seizures, slow or irregular heartbeat, severe abdominal pain, slurred speech.

Other: Blurred vision, dizziness, drowsiness, increased sweating, increased urination, weakness, muscle twitches.

What products might interact with this medicine?

When you take this medicine with other medicines, it can change the way this or any of the other medicines work. Nonprescription medicines, vitamins, natural remedies, and certain foods may also interact. Using these products together might cause harmful side effects. Talk to your healthcare provider if you are taking:

• anesthetics
• antiarrhythmics (medicines to treat irregular heartbeat) such as digoxin (Digitek, Lanoxin, Lanoxicaps), procainamide (Procanbid, Pronestyl, Pronestyl-SR), and quinidine
• antibiotics such as amikacin (Amikin), gentamicin (Garamycin, Gentak), Kanamycin (Kantrex), streptomycin, tobramycin (Nebcin, Tobrex), demeclocycline (Declomycin), doxycycline (Doryx, Periostat, Vibramycin, Vibra-Tabs), minocycline (Minocin, Vectrin), oxytetracycline (Terramycin), tetracycline (Achromycin V, Sumycin, Panmycin, Tetracyn), cinoxacin (Cinobac), ciprofloxacin (Cipro, Cipro XR), levofloxacin (Levaquin), lomefloxacin (Maxaquin), nalidixic acid (NegGram), norfloxacin (Noroxin), ofloxacin (Floxin), and trovafloxacin (Trovan)
• anticholinergic medicines such as benztropine (Cogentin), dicyclomine (Bentyl), atropine sulfate, belladonna, propantheline (Pro-Banthine), methscopolamine (Pamine), hyoscyamine (Levsin, Levsinex), amantadine (Symmetrel), procyclidine (Kemadrin), and trihexyphenidyl (Artane)
• beta blockers such as atenolol (Tenormin), acebutolol (Sectral), pindolol, metoprolol (Lopressor, Toprol XL), sotalol (Betapace), nadolol (Corgard), propranolol (Inderal), labetalol (Normodyne, Trandate), and carvedilol (Coreg)
• corticosteroids such as cortisone (Cortone), betamethasone (Celestone), dexamethasone, fludrocortisone (Florinef), hydrocortisone (Cortef, Hydrocortone, A-HydroCort), methylprednisolone (Medrol), prednisone (Meticorten), prednisolone (Delta-Cortef), and triamcinolone (Aristocort, Kenacort)
• digoxin (Lanoxin)
• magnesium (an ingredient in many antacids)
• mecamylamine (Inversine)
• other medicines to treat myasthenia gravis

Keep a list of all your medicines with you. List all the prescription medicines, nonprescription medicines, supplements, natural remedies, and vitamins that you take. Be sure that you tell all healthcare providers who treat you about all the products you are taking.

How should I store this medicine?

Store this medicine at room temperature. Keep the container tightly closed. Protect it from heat, high humidity, and bright light.

This advisory includes selected information only and may not include all side effects of this medicine or interactions with other medicines. Ask your healthcare provider or pharmacist for more information or if you have any questions.

Ask your pharmacist for the best way to dispose of outdated medicine or medicine you have not used. Do not throw medicine in the trash.

Keep all medicines out of the reach of children.

Do not share medicines with other people.