Drug interactions
Metolazone + Salmeterol
Severity: Moderate
Metolazone and Salmeterol: moderate interaction.
Last updated
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Summary
Metolazone causes potassium loss through the kidney and beta-2 agonists such as salmeterol shift potassium into cells. Together they can lead to clinically relevant hypokalemia, raising the risk of arrhythmia, especially in patients with heart disease or on digoxin.
What this interaction means in plain words
Metolazone and Salmeterol can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Metolazone belongs to Cardiovascular; Salmeterol belongs to Respiratory.
Why it happens
Additive hypokalemia: renal potassium wasting from the thiazide-like diuretic plus beta-2 mediated intracellular potassium shift.
What to do
Monitor serum potassium and magnesium, replace as needed, and take particular care with high doses of salmeterol or other hypokalemia-causing drugs.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Salmeterol
- Ritonavir + Salmeterol Contraindicated
- Salmeterol + Saquinavir Contraindicated
- Amitriptyline + Salmeterol Major
- Arformoterol + Salmeterol Major
- Atazanavir + Salmeterol Major
- Budesonide-formoterol + Salmeterol Major
Other interactions of Metolazone
Frequently asked questions
Can I take Metolazone with Salmeterol?
MediHelp rates the interaction as moderate. Metolazone and Salmeterol can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Metolazone causes potassium loss through the kidney and beta-2 agonists such as salmeterol shift potassium into cells. Together they can lead to clinically relevant hypokalemia, raising the risk of arrhythmia, especially in patients with heart disease or on digoxin.
How serious is the interaction between Metolazone and Salmeterol?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor serum potassium and magnesium, replace as needed, and take particular care with high doses of salmeterol or other hypokalemia-causing drugs.
What other medicines interact with Salmeterol?
MediHelp also lists interactions of Salmeterol with, for example, Ritonavir, Saquinavir, Amitriptyline. The full list is on the Salmeterol page.
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