Pyridostigmine: uses, dosing, side effects & brands
Pyridostigmine is a cholinesterase inhibitor sold in the U.S. under 3 brand and generic names, for drug-induced abnormalities and myasthenia gravis. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.
Key facts
- Drug class
- Cholinesterase Inhibitor
- Treats (across its forms)
- Drug-Induced Abnormalities and Myasthenia Gravis
- Available as
- Solution · Tablet · Tablet, extended release · Injectable
- Sold as
- 3 products — Pyridostigmine Bromide, Regonol and Mestinon
- Prescription?
- Prescription only
- Generic available?
- Yes
- What the pharmacy pays
- about $0.60 per ml — not your price
How Regonol is dosed
From the FDA label for Regonol (application NDA017398). Other pyridostigmine products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.
REGONOL ® (pyridostigmine bromide injection, USP) 2 mL single-dose ampule is for intravenous use only. This drug should be administered by or under the supervision of experienced clinicians familiar with the use of agents which reverse or antagonize the effects of neuromuscular blocking agents. Dosage must be individualized in each case. The dosage information which follows is derived from studies based upon units of drug per unit of body weight and is intended to serve as a guide only. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit. NOTE: CONTAINS BENZYL ALCOHOL (see PRECAUTIONS ) Reversal doses of REGONOL ® range from 0.1 to 0.25 mg/kg. 5,10,11,12,13 The onset time to peak effect is dose-dependent; return of twitch height to 90% of control occurs within approximately 6 minutes following administration of a 0.25 mg/kg dose of REGONOL ® . 5,12 At lower doses, full recovery usually occurs within 15 minutes in most patients, although others may require a half-hour or more. When REGONOL ® is given intravenously to reverse the action of muscle relaxant drugs, it is recommended that atropine sulfate (0.6 to 1.2 mg) or an equipotent dose of glycopyrrolate be given immediately prior to or simultaneously with the administration of REGONOL ® . Side effects, notably excessive…
Everything below is the FDA label for Regonol (injectable). Pyridostigmine is also sold as solution, tablet and tablet, extended release, and those are different medicines to take — follow the label for the one you were prescribed.
Regonol side effects
The side effects of pyridostigmine bromide are most commonly related to overdosage and generally are of two varieties, muscarinic and nicotinic. Among those in the former group are nausea, vomiting, diarrhea, abdominal cramps, increased peristalsis, increased salivation, increased bronchial secretions, miosis, and diaphoresis. Nicotinic side effects are comprised chiefly of muscle cramps, fasciculation, and weakness. Muscarinic side effects can usually be counteracted by atropine. As with any compound containing the bromide radical, a skin rash may be seen in an occasional patient. Such reactions usually subside promptly upon discontinuance of the medication. Thrombophlebitis has been reported subsequent to intravenous administration.
Who shouldn’t take Regonol
Known hypersensitivity to anticholinesterase agents; intestinal and urinary obstructions of mechanical type.
Regonol drug interactions
Concomitant administration of REGONOL ® (pyridostigmine bromide injection, USP) and 4-aminopyridine has been reported to delay the onset of action of REGONOL ® . 9 Antibiotics Parenteral administration of high doses of certain antibiotics may intensify or produce neuromuscular block through their own pharmacologic actions. The following antibiotics have been associated with various degrees of paralysis: aminoglycosides (such as neomycin, streptomycin, kanamycin, gentamicin, and dihydrostreptomycin); tetracyclines; bacitracin; polymyxin B; colistin; and sodium colistimethate. If these or other newly introduced antibiotics are used in conjunction with nondepolarizing neuromuscular blocking drugs during surgery, unexpected prolongation of neuromuscular block or resistance to its reversal should be considered a possibility. Other Experience concerning injection of quinidine during recovery from use of nondepolarizing muscle relaxants suggest that recurrent paralysis may occur. This possibility must be considered when administering anticholinesterase agents to antagonize neuromuscular blockade induced by nondepolarizing muscle relaxants. Electrolyte imbalance and diseases which lead to electrolyte imbalance, such as adrenal cortical insufficiency, have been shown to alter neuromuscular blockade. Depending on the nature of the imbalance, either enhancement or inhibition may be expected. Magnesium salts, administered for the management of toxemia of pregnancy, may enhance the neuromuscular blockade. The possibility that such circumstances may interfere with the restoration of neuromuscular function should be considered when administering REGONOL ® .
Every pyridostigmine product we track (3)
Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.
| # | Drug | Rating | Type | Form | Generic? | Pharmacy pays | |
|---|---|---|---|---|---|---|---|
| 1 | 70/100 | Prescription | Solution | Generic | $1 | View → | |
| 2 | 68/100 | Prescription | Injectable | Generic | $1 | View → | |
| 3 | Not yet rated | Prescription | Solution | Generic | $1 | View → |
What pyridostigmine pills look like
Imprint codes, colour and shape from the FDA’s labelling data. Match the imprint on your pill — or search any imprint.
How long pyridostigmine keeps
The date on a sealed pack is not the only one: some pyridostigmine labels start a second clock once the product is opened or mixed, as short as 3 months.
Does pyridostigmine expire? The in-use limits and storage rules from its labelsPyridostigmine and breastfeeding
From LactMed, the US National Library of Medicine’s Drugs and Lactation Database — quoted, not rewritten.
Full LactMed record for pyridostigmine: levels in milk, effects in breastfed infants, and the drugs it would consider insteadBecause of the low levels of pyridostigmine in breastmilk, amounts ingested by the infant are small and infant serum levels are very low. Pyridostigmine is not expected to cause any adverse effects in breastfed infants. Most mothers with myasthenia gravis are able to nurse successfully with pyridostigmine treatment, but occasionally breastfeeding must be discontinued to avoid excessive fatigue in the mother.
National Institute of Child Health and Human Development, record revised December 19, 2022. LactMed states its information is not a substitute for professional judgement.
What people report to the FDA about pyridostigmine
The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 1,873 reports naming pyridostigmine, and the FDA flagged 70% of those reports as serious. The effects reported most often — leaving out reports about overdose, misuse or the condition being treated, which dominate the raw list for common medicines:
- myasthenia gravis183 reports
- fatigue166 reports
- dyspnoea140 reports
- asthenia123 reports
- diarrhoea115 reports
- headache115 reports
- nausea99 reports
- malaise95 reports
Read these as a signal, not a rate. A report does not mean pyridostigmine caused the effect — anyone can file one, and many describe people taking several medicines for several conditions. Crucially there is no denominator: FAERS does not record how many people took the drug, so these counts cannot be turned into “X% of patients” — a bigger number often just means a more widely used or more talked-about drug. Duplicates exist, and publicity drives reporting. For what is actually established, read the FDA label section above.
Source: openFDA drug/event (FAERS), retrieved July 26, 2026.
Related calculators
Frequently asked questions
What is Regonol?
Regonol (Pyridostigmine Bromide) is a cholinesterase inhibitor used to treat Drug-Induced Abnormalities, Myasthenia Gravis.
What kind of drug is pyridostigmine?
The FDA classifies pyridostigmine as a cholinesterase inhibitor. Cholinesterase inhibitors block the enzyme that breaks down acetylcholine, a chemical messenger nerves use to communicate. By letting acetylcholine build up and act longer, they can help preserve memory and thinking in Alzheimer's disease, where this messenger runs low. If you are checking whether it is safe to combine with something else, the class is what matters — two drugs from the same class usually should not be stacked.
Can you take pyridostigmine with other medicines?
It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run pyridostigmine against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What brand names is pyridostigmine sold under?
We track 3 pyridostigmine-containing products in the U.S.: Pyridostigmine Bromide, Regonol and Mestinon. They are the same active ingredient; they differ in form, manufacturer, price and FDA recall record.
What forms does pyridostigmine come in?
Across the brands we track, pyridostigmine is currently marketed as solution, tablet, tablet, extended release and injectable, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.
Is there a generic pyridostigmine?
Yes. Our catalog lists 1 generic pyridostigmine product alongside the brand versions. A generic has the same active ingredient and must meet the FDA's bioequivalence standard; it usually costs less. Ask your pharmacist which one your plan covers.
Cite this page
- APA
- pharmaranks. (2026, July 24). Pyridostigmine: uses, dosing, side effects & brands. https://pharmaranks.com/drugs/pyridostigmine
- MLA
- “Pyridostigmine: uses, dosing, side effects & brands.” pharmaranks, 24 July 2026, https://pharmaranks.com/drugs/pyridostigmine.
We summarise public FDA and NIH sources — for a clinical claim, cite the primary source we link to as well.
Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.
Read the full FDA label for pyridostigmine on DailyMed (NIH) ↗.