TheraRadar
Data updated: May 26, 2026

MESTINON (pyridostigmine bromide)

Trial Activity: Stable 2 active trials
CNS Approved 1955-04-06

Mestinon treats myasthenia gravis, a condition that affects the communication between nerves and muscles. It helps patients with this disorder by providing a longer duration of action compared to similar medications like neostigmine. This drug is often used because it tends to cause fewer gastrointestinal side effects while managing symptoms.

Source: FDA Label • BAUSCH

How MESTINON Works

This medication works by stopping the enzyme cholinesterase from breaking down acetylcholine. By preserving this chemical messenger, the drug allows nerve impulses to pass more freely across the neuromuscular junction. This improved transmission helps strengthen the connection between the nervous system and the muscles.

Development Insights

James J. Peters Veterans Affairs Medical Center conducting 2 trials (20%)
31 indications explored (Broad Platform)
parkinson disease (1 trials)
constipation (1 trials)
postoperative ileus (1 trials)
4
Indications
--
Phase 3 Trials
71
Years on Market

Details

Status
Prescription
First Approved
1955-04-06
Routes
ORAL, INJECTION
Dosage Forms
SYRUP, INJECTABLE, TABLET, EXTENDED RELEASE, TABLET

Companies

Active Ingredient: PYRIDOSTIGMINE BROMIDE

MESTINON Approval History

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Original
New Indication
New Form
Label Update
48 FDA actions from 1955 to 2019
Oct 2019 SUPPL
Label · Labeling
Feb 2015 SUPPL
Mfg · Manufacturing (CMC)
Sep 2014 SUPPL
Mfg · Manufacturing (CMC)

What MESTINON Treats

1 indications

MESTINON is approved for 1 conditions since its original approval in 1955. These indications span multiple therapeutic areas including oncology, immunology, and more.

  • Myasthenia Gravis
Source: FDA Label

MESTINON Competitive Set

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Filters applied: drops same-active-ingredient (505(b)(2) reformulations), route-mismatch (topical vs systemic), and cross-therapeutic-area matches in same-indication rings.

Drugs Similar to MESTINON

3 of 5

FDA-approved drugs for similar conditions. Compare mechanisms and indications to understand treatment alternatives.

IMAAVY
NIPOCALIMAB-AAHU
1 shared
Johnson & Johnson
Shared indications:
Myasthenia Gravis
PROTOPAM CHLORIDE
PRALIDOXIME CHLORIDE
1 shared
Baxter
Shared indications:
Myasthenia Gravis
RYSTIGGO
ROZANOLIXIZUMAB-NOLI
1 shared
UCB INC
Shared indications:
Myasthenia Gravis
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Clinical Trial Registry

10 trials
Trial Sponsor ID Phase Status Title
NCT05603715 STUDY00001877 Ph 2 recruiting Pyridostigmine for the Treatment of Constipation in Parkinson Disease
NCT05334485 PESTI 21-915 Ph 2, Ph 3 recruiting Pyridostigmine Efficacy and Safety for Treatment of Ileus After Colorectal Surgery
NCT02893553 results posted WEC-16-015 Ph 2 completed The Effects of Normalizing Blood Pressure on Cerebral Blood Flow in Hypotensive Individuals With Spinal Cord Injury
NCT02227823 EMOTAS 1376 Ph 2 completed Safety and Efficacy Study of Pyridostigmine on Patients With Spinal Muscular Atrophy Type 3
NCT03674541 results posted 2018P001871 Ph 2 completed The Exercise Response to Pharmacologic Cholinergic Stimulation in Myalgic Encephalomyelitis / Chronic Fatigue Syndrome
NCT02308124 results posted 1409066609 Ph 4 completed Treatment and Prognosis of Neurogenic Orthostatic Hypotension : A Prospective Randomized Study
NCT01993680 KEK-ZH-NR. 2011-0358 Ph 2 completed Orthostatic Dysregulation and Associated Gastrointestinal Dysfunction in Parkinson's Disease -Treatment
NCT03312244 Ref. 1873 Ph 2 suspended Pyridostigmine as Immunomodulator in People Living With HIV
NCT01415921 APP-HF results posted 10-02167 10-02167, 1R01HL103988 Ph 2 completed Safety Study of Pyridostigmine in Heart Failure
NCT02307526 results posted WEC-11-04 Ph 2 completed Acetylcholinesterase Inhibition and Orthostatic Hypotension in SCI
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Active Pipeline

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Ongoing clinical trials by development phase

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Key Completed Trials

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Completed studies with published results, ranked by significance

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Trial Timeline

Full development history with FDA approval milestones

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Understanding FDA Approval Types
Count Type What it means
- ORIG Original approval - drug first enters market
- SUPPL - Efficacy New indication (new disease/condition approved)
- SUPPL - Labeling Label text changes (warnings, dosing updates)
- SUPPL - Manufacturing Production changes (new facility)
- SUPPL - Chemistry Formulation changes (new dosage strength)

Green lines in the timeline show ORIG and Efficacy approvals - the clinically meaningful milestones.

MESTINON FDA Label Details

Indications & Usage

FDA Label (PDF)

MESTINON is indicated for the treatment of Myasthenia Gravis.

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Data Sources

Data sourced from official FDA and NIH databases. Click links to verify on original sources.

How We Calculate These Metrics

Trial Activity Stage

Measures the current development activity pattern based on trial phases, status, and trends. Important: This measures R&D activity, not commercial lifecycle.

Trial statuses: "Active" means recruiting or ongoing. "Completed" means reached planned endpoint. "Terminated" means stopped early—often due to safety, efficacy, or business reasons.

  • Growth: High proportion of early-phase trials (Phase 1/2), active development
  • Expansion: Significant Phase 3 activity, approaching or pursuing approvals
  • Mature: Substantial Phase 4 post-marketing studies
  • Stable: Mixed phase distribution, steady development
  • Declining: Low active trial ratio, reduced R&D investment