Chlorthalidone and Fosinopril interaction

Chlorthalidone and Fosinopril: both prescribing labels describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.

Moderate

Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.

What the FDA labels say

From the Chlorthalidone (Thalitone) label · effective 2026-06-25

Moderate

Effect of chlorthalidone on other drugs Chlorthalidone may add to or potentiate the action of other antihypertensive drugs.

Drug interactionsby drug classView label on DailyMed

From the Fosinopril (Fosinopril Sodium) label · effective 2024-05-16

Moderate

In separate single or multiple dose pharmacokinetic interaction studies with chlorthalidone, nifedipine, propranolol, hydrochlorothiazide, cimetidine, metoclopramide, propantheline, digoxin, and warfarin, the bioavailability of fosinoprilat was not altered by coadministration of fosinopril with any one of these drugs.

Drug interactionsnames ChlorthalidoneView label on DailyMed
Moderate

Symptomatic hypotension is most likely to occur in patients who have been volume- and/or salt-depleted as a result of prolonged diuretic therapy, dietary salt restriction, dialysis, diarrhea, or vomiting.

Warningsby drug classView label on DailyMed
Moderate

In such patients, fosinopril sodium therapy should be started under close medical supervision; they should be followed closely for the first 2 weeks of treatment and whenever the dose of fosinopril or diuretic is increased.

Warningsby drug classView label on DailyMed
Moderate

Consideration should be given to reducing the diuretic dose in patients with normal or low blood pressure who have been treated vigorously with diuretics or who are hyponatremic.

Warningsby drug classView label on DailyMed
Moderate

Drug Interactions Diuretics Patients on diuretics, especially those with intravascular volume depletion, may occasionally experience an excessive reduction of blood pressure after initiation of therapy with fosinopril sodium tablets.

Drug interactionsby drug classView label on DailyMed

Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.

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Not medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.