Drug Interaction Report

Pyridostigmine and Hydrocortisone Injection: Interaction Details

A pharmacist-reviewed analysis of the Pyridostigmine and Hydrocortisone Injection interaction: the documented clinical effects, severity rating, onset, mechanism, and management considerations, with cited references throughout.

AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Pyridostigmine

Mestinon Mestinon® Mestinon® Syrup Mestinon® Timespan® Regonol
+

Hydrocortisone Injection

A-Hydrocort® Ala-Cort Alkindi Alocane Anti-Itch Anucort-HC Anusol HC Aquanil HC Aquaphor Itch Relief
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Dr. Brian Staiger, PharmD, BCPS
Updated Aug 8, 2026
Editorial policy · Data sources
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Interaction severity
Moderate
Can be significant — usually manageable with monitoring.
How we grade severity & evidence

Severity levels

  • Contraindicated: These should generally not be used together.
  • Major: Potentially serious — often needs a change or close monitoring.
  • Moderate: Can be significant — usually manageable with monitoring.
  • Minor: Usually limited clinical impact.

Evidence grades

  • Established: Well documented — supported by controlled studies or strong clinical data.
  • Probable: Good supporting evidence, though not definitively proven.
  • Suspected: Some evidence suggests this interaction, but it is not well established.
  • Possible: Limited or conflicting evidence; the interaction may occur.
  • Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.

Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.

Onset
delayed
Evidence
theoretical
Severity
Moderate

What happens

Decreased pyridostigmine effectiveness

Interaction Deep Dive

In several case reports of patients with myasthenia gravis maintained on anticholinesterases, the addition of corticosteroids resulted in a worsening of the patients' condition (after 48 hours)123.

Why it happens (mechanism)

Unknown

Common questions

Can I take Pyridostigmine and Hydrocortisone Injection together?

Decreased pyridostigmine effectiveness Always confirm with your pharmacist or prescriber before making any change.

How serious is the Pyridostigmine and Hydrocortisone Injection interaction?

It is rated moderate. Can be significant — usually manageable with monitoring.

How quickly could this interaction happen?

The documented onset is "delayed". Effects tend to build up gradually over days to weeks.

How strong is the evidence for this interaction?

The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.

Questions for your pharmacist

  • Does my dose of Pyridostigmine or Hydrocortisone Injection need adjusting while I take them together?
  • What symptoms should prompt me to call you or my prescriber right away?
  • Does the timing of my doses matter for this combination?
  • Is there anything you'd monitor while I'm on both?

References (3)

  1. Namba T: Corticotropin therapy in patients with myasthenia gravis. Electrophysiologic, pharmacologic studies. Arch Neurol 1972; 26:144-150. PubMed
  2. Brunner NG, Namba T, & Grob D: Corticosteroids in management of severe, generalized myasthenia gravis. Effectiveness and comparison with corticotropin therapy. Neurology 1972; 22:603-610. DOI
  3. Warmolts JR, Engel WK, & Whitaker JN: Alternate-day prednisone in a patient with myasthenia gravis. Lancet 1970; 2:1198-1199. DOI
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Pyridostigmine

Keep reading about Pyridostigmine

All Pyridostigmine interactions (2) Pyridostigmine drug information
Hydrocortisone Injection

Keep reading about Hydrocortisone Injection

All Hydrocortisone Injection interactions (393) Hydrocortisone Injection drug information
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