Does Quinapril Hydrochloridehydrochlorothiazide Interact with Hydrochlorothiazide?
Quinapril Hydrochloridehydrochlorothiazide and Hydrochlorothiazide have a moderate drug interaction according to U.S. FDA drug labeling data. Drug Interactions Agents Increasing Serum Potassium Coadministration of quinapril and hydrochlorothiazide with other drugs that raise serum potassium levels may result in hyperkalemia. Because renal clearance of lithium is reduced by thiazides, the risk of lithium toxicity is presumably raised further when, as in therapy with quinapril and hydrochlorothiazide, a thiazide diuretic is coadministered with the ACE inhibitor. Quinapril and hydrochlorothiazide and lithium should be coadministered with caution, and frequent monitoring of serum lithium levels is recommended. Patients taking both medications should consult their healthcare provider before starting, stopping, or changing the dosage of either drug. This information is based on official FDA drug labeling sourced from OpenFDA and the NIH National Library of Medicine.
- Severity
- Moderate
- Quinapril Hydrochloridehydrochlorothiazide Class
- Thiazide Diuretic
- Hydrochlorothiazide Class
- Thiazide Diuretic
- Management
- Monitor for effects
- Data Source
- U.S. FDA via OpenFDA
What To Tell Your Doctor or Pharmacist
If you are taking Quinapril Hydrochloridehydrochlorothiazide and your doctor is considering prescribing Hydrochlorothiazide (or vice versa), make sure to:
- Inform your doctor and pharmacist of all current medications, including over-the-counter drugs and supplements
- Ask whether the benefits of combining these medications outweigh the risks for your specific situation
- Ask what symptoms to watch for that would indicate the interaction is causing problems
- Ask whether any dosage adjustments are needed
- Never stop or change either medication without first consulting your healthcare provider