Drug interactions
Fosinopril + Lithium
Severity: Major
Fosinopril 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
ACE inhibitors can raise serum lithium concentrations and have caused lithium toxicity, sometimes severe. Symptoms include tremor, confusion, ataxia and gastrointestinal upset, and the risk is higher in older patients and with dehydration or renal impairment.
What this interaction means in plain words
Fosinopril 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 belongs to Cardiovascular; Lithium belongs to Central Nervous System.
Why it happens
ACE inhibition reduces renal sodium and lithium clearance by promoting sodium loss and lowering glomerular filtration, increasing proximal lithium reabsorption.
What to do
Avoid the combination if possible; if used, measure lithium levels before and within the first week or two after starting, and after dose changes. Reduce the lithium dose as needed and counsel on toxicity symptoms and hydration.
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
- Aliskiren + Fosinopril Contraindicated
- Fosinopril + Protein a column Contraindicated
- Fosinopril + Sacubitril / valsartan Contraindicated
- Fosinopril + Sacubitril-valsartan Contraindicated
- Amifostine + Fosinopril Major
- Amiloride + Fosinopril 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 with Lithium?
MediHelp rates the interaction as major. Fosinopril 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. ACE inhibitors can raise serum lithium concentrations and have caused lithium toxicity, sometimes severe. Symptoms include tremor, confusion, ataxia and gastrointestinal upset, and the risk is higher in older patients and with dehydration or renal impairment.
How serious is the interaction between Fosinopril 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 the combination if possible; if used, measure lithium levels before and within the first week or two after starting, and after dose changes. Reduce the lithium dose as needed and counsel on toxicity symptoms and hydration.
What other medicines interact with Fosinopril?
MediHelp also lists interactions of Fosinopril with, for example, Aliskiren, Protein a column, Sacubitril / valsartan. The full list is on the Fosinopril page.
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