Drug interactions
Fosinopril-hydrochlorothiazide + Lithium
Severity: Major
Fosinopril-hydrochlorothiazide and Lithium: major interaction.
Last updated Sources: US FDA label
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
Thiazide diuretics and ACE inhibitors both reduce renal lithium clearance, and serum lithium concentrations can rise to toxic levels. Toxicity may present with tremor, confusion, ataxia, vomiting and, in severe cases, seizures or renal injury. The combination of both agents in one tablet increases the risk.
What this interaction means in plain words
Fosinopril-hydrochlorothiazide and Lithium can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Fosinopril-hydrochlorothiazide belongs to Cardiovascular; Lithium belongs to Central Nervous System.
Why it happens
Sodium depletion from the thiazide and ACE inhibition increases proximal tubular lithium reabsorption and reduces lithium excretion.
What to do
Avoid if possible; otherwise reduce the lithium dose and check serum lithium within about a week of starting and after dose changes. Educate the patient about toxicity symptoms and maintain hydration and sodium intake.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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References
Other interactions of Fosinopril-hydrochlorothiazide
- Aliskiren + Fosinopril-hydrochlorothiazide Contraindicated
- Dofetilide + Fosinopril-hydrochlorothiazide Contraindicated
- Fosinopril-hydrochlorothiazide + Protein a column Contraindicated
- Fosinopril-hydrochlorothiazide + Sacubitril / valsartan Contraindicated
- Aldesleukin + Fosinopril-hydrochlorothiazide Major
- Amifostine + Fosinopril-hydrochlorothiazide Major
Other interactions of Lithium
- Lithium + Thioridazine Contraindicated
- Lithium + Vandetanib Contraindicated
- Aceclofenac + Lithium Major
- Acemetacin + Lithium Major
- Amisulpride + Lithium Major
- Amlodipine-benazepril + Lithium Major
Frequently asked questions
Can I take Fosinopril-hydrochlorothiazide with Lithium?
MediHelp rates the interaction as major. Fosinopril-hydrochlorothiazide and Lithium can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Thiazide diuretics and ACE inhibitors both reduce renal lithium clearance, and serum lithium concentrations can rise to toxic levels. Toxicity may present with tremor, confusion, ataxia, vomiting and, in severe cases, seizures or renal injury. The combination of both agents in one tablet increases the risk.
How serious is the interaction between Fosinopril-hydrochlorothiazide and Lithium?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid if possible; otherwise reduce the lithium dose and check serum lithium within about a week of starting and after dose changes. Educate the patient about toxicity symptoms and maintain hydration and sodium intake.
What other medicines interact with Fosinopril-hydrochlorothiazide?
MediHelp also lists interactions of Fosinopril-hydrochlorothiazide with, for example, Aliskiren, Dofetilide, Protein a column. The full list is on the Fosinopril-hydrochlorothiazide page.
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