Drug Interaction Report

Montelukast and Prednisone: Interaction Details

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

Montelukast

Singulair Singulair®
+

Prednisone

Deltasone Rayos
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Updated Aug 8, 2026
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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.

Of 18 documented Montelukast interactions, 3 are rated moderate — including this one.
Onset
delayed
Evidence
probable
Severity
Moderate

What happens

Severe peripheral edema

Interaction Deep Dive

In drug interaction studies, montelukast at doses of greater than or equal to 100 mg daily at steady-state did not have a clinically significant effect on the pharmacokinetics of oral predniSONE2. The first case report of marked peripheral edema associated with the concomitant use of predniSONE and montelukast has been described. A 23-year-old patient with a history of asthma and allergies was treated with predniSONE and montelukast. He subsequently developed peripheral edema on day 10 of predniSONE therapy. When predniSONE was withdrawn from the treatment regimen, the edema resolved 1.

Why it happens (mechanism)

Corticosteroid-induced renal tubular sodium and fluid retention

Literature reports

1 report — tap to read

a) The first case report of an interaction between montelukast and predniSONE is described in a 23-year-old male. The man developed severe peripheral edema after being treated with both predniSONE and montelukast for asthma. The man presented with acute respiratory symptoms. He had a history of exercise-induced and perennial asthma, house dust mite allergy and rhinoconjunctivitis. The patient was treated with salmeterol, fluticasone propionate, cetirizine, and a predniSONE burst of 40 mg/day for one week, then tapering to 20 mg/day for another week. Severe asthma symptoms recurred after predniSONE therapy was discontinued. Additional bursts of predniSONE 60 mg/day for one week followed by 40 mg/day for another week was required. Oral montelukast 10 mg/ day, given at night was administered as well. The patient subsequently developed severe peripheral edema without dyspnea on the tenth day of predniSONE treatment. The patient gained 13 kg but laboratory tests (creatinine clearance, urinalysis, 24-hour urine protein determination, routine biochemistry, complete blood count, differential, and erythrocyte sedimentation rate) were all within normal limits. PredniSONE therapy was discontinued. The patient's asthma became controlled, and the edema and excess weight had resolved. The patient did not experience any relapses in the following three months. The patient tolerated predniSONE when used without montelukast. The patient also tolerated montelukast when used without predniSONE. The author suggests that corticosteroid-induced renal tubular sodium and fluid retention may have occurred when montelukast was added to the patient's therapy 1.

Common questions

Can I take Montelukast and Prednisone together?

Severe peripheral edema Always confirm with your pharmacist or prescriber before making any change.

How serious is the Montelukast and Prednisone 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 "probable". Good supporting evidence, though not definitively proven.

Questions for your pharmacist

  • Does my dose of Montelukast or Prednisone 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 (2)

  1. Geller M: Marked peripheral edema associated with montelukast and prednisone. Ann Intern Med 2000; 132(11):924. PubMed
  2. Product Information: Singulair(R), montelukast sodium. Merck & Co. Inc. Whitehouse Station, NJ, 2003. DailyMed
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This information is for education, not a substitute for professional medical advice. Do not start, stop, or change any medication without talking to your pharmacist or prescriber.