C9 H13 N2 O2Br
3-hydroxy-1-methylpyridinium bromide dimethylcarbamate
Pyridostigmine is in Phase 2 development as an HIV treatment.
(Compound details obtained from ChemIDplus Advanced,1 Treatment Action Group Pipeline Report 2020,2 and Current Neuropharmacology article3)
What is pyridostigmine?
Pyridostigmine is a drug that has been approved by the Food and Drug Administration (FDA) to treat a condition called myasthenia gravis and to reverse the effects of muscle relaxants.4,5 In addition, pyridostigmine has been used in the military as a pretreatment for exposure to the chemical nerve agent Soman.6 It is also being studied as an to treat HIV 2
As an investigational HIV drug, pyridostigmine belongs to a group of drugs called.2 Immune modulators (also called immunomodulators) are substances that help to activate, boost, or restore normal immune function.
Researchers are currently studying whether pyridostigmine added to(ART) can help a person with HIV increase their .7
Which clinical trials are studying pyridostigmine?
Study Name: NCT00518154
Status: This study has been completed.
Purpose: The purpose of this study was to evaluate whether adding pyridostigmine to ART would increase the CD4 count in individuals who had low CD4 counts despite having on ART.8
Study Name: NCT03312244
Status: See the ClinicalTrials.gov record for this study’s status.
Purpose: The purpose of this study is to evaluate whether adding pyridostigmine to ART can increase CD4 counts in individuals who have viral suppression on ART.7
For more details on the studies listed above, see the Health Professional version of this drug summary.
An additional Phase 1/2 study (NCT04353778) is evaluating whether pyridostigmine can reduce bacterial overgrowth in the small intestines and signs of inflammation in adults with HIV.9
What side effects might pyridostigmine cause?
One goal of HIV research is to identify new drugs that have fewer side effects. In the NCT00518154 study discussed under the previous question, seven participants were enrolled to receive pyridostigmine in addition to ART. No side effects related to pyridostigmine were reported during the study.10
Because pyridostigmine is still being studied, information on possible side effects of the drug is not complete. As testing of pyridostigmine continues, additional information on possible side effects will be gathered.
Where can I get more information about clinical trials studying pyridostigmine?
More information about pyridostigmine-related research studies is available from ClinicalTrials.gov.
Some clinical trials may be looking for volunteer participants. Your health care provider can help you decide whether participating in a NIH Clinical Research Trials and You.is right for you. For more information, visit
- United States National Library of Medicine. ChemIDplus Advanced: Pyridostigmine bromide. https://chem.nlm.nih.gov/chemidplus/rn/101-26-8. Accessed March 12, 2021
- Jefferys R. Research toward a cure and immune-based therapies pipeline 2020. Treatment Action Group Pipeline Report 2020. https://www.treatmentactiongroup.org/wp-content/uploads/2020/07/pipeline_cure_2020.pdf. Accessed March 12, 2021
- Čolović MB, Krstić DZ, Lazarević-Pašti TD, Bondžić AM, Vasić VM. Acetylcholinesterase inhibitors: pharmacology and toxicology. Curr Neuropharmacol. 2013;11(3):315-335. doi:10.2174/1570159X11311030006
- Bausch Health US, LLC. Mestinon: full prescribing information, December 2, 2020. DailyMed. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=a851795e-b7a8-40c3-9922-5e79d3eb4d92. Accessed March 12, 2021
- Sandoz Inc. Regonol: full prescribing information, January 14, 2019. DailyMed. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=208af931-a44e-43bf-a265-8e08534dc55f. Accessed March 12, 2021
- Surgeon General-Department of the Army (TSG-DA). Pyridostigmine bromide: full prescribing information, January 14, 2021. DailyMed. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=0b296555-c32f-42db-b5f3-ea981a3dd2f8. Accessed March 12, 2021
- Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran. Study of the role of peripheral acetylcholinesterase inhibitor pyridostigmine as immunomodulators in a population of patients living with human immunodeficiency virus infection. In: ClinicalTrials.gov. Bethesda (MD): National Library of Medicine (US). Registered April 1, 2017. NLM Identifier: NCT03312244. https://clinicaltrials.gov/ct2/show/NCT03312244. Accessed March 12, 2021
- Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran. Pilot study of an ACh-E inhibitor upon immune activation markers in HIV-1 infected patients receiving highly active antiretroviral therapy (HAART) showing an incomplete immune response. In: ClinicalTrials.gov. Bethesda (MD): National Library of Medicine (US). Registered August 17, 2007. NLM Identifier: NCT00518154. https://clinicaltrials.gov/ct2/show/NCT00518154. Accessed March 12, 2021
- Icahn School of Medicine at Mount Sinai. Effects of vagal dysfunction on gastrointestinal and inflammatory pathways in HIV. In: ClinicalTrials.gov. Bethesda (MD): National Library of Medicine (US). Registered April 17, 2020. NLM Identifier: NCT04353778. https://clinicaltrials.gov/ct2/show/NCT04353778. Accessed March 12,2021
- Valdés-Ferrer SI, Crispín JC, Belaunzarán-Zamudio PF, et al. Add-on pyridostigmine enhances CD4+ T-cell recovery in HIV-1-infected immunological non-responders: a proof-of-concept study. Front Immunol. 2017;8. doi:10.3389/fimmu.2017.01301
Last Reviewed: March 12, 2021