Drug interactions
Hydrochlorothiazide-lisinopril + Sulfamethoxazole
Severity: Moderate
Hydrochlorothiazide-lisinopril and Sulfamethoxazole: 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
Thiazide diuretics can cause hyponatremia, and sulfamethoxazole-trimethoprim has also been associated with low sodium. Combined with an ACE inhibitor, the trimethoprim component additionally raises the risk of hyperkalemia and renal impairment, especially in older patients.
What this interaction means in plain words
Hydrochlorothiazide-lisinopril and Sulfamethoxazole 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.
Why it happens
Additive effects on sodium and potassium handling; trimethoprim blocks distal tubular epithelial sodium channels, adding to ACE inhibitor-related potassium retention.
What to do
Monitor serum sodium, potassium and creatinine within the first week of co-trimoxazole therapy. Consider an alternative antibiotic in patients with renal impairment or a high baseline hyperkalemia risk.
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 Hydrochlorothiazide-lisinopril
- Dofetilide + Hydrochlorothiazide-lisinopril Contraindicated
- Hydrochlorothiazide-lisinopril + Sacubitril / valsartan Contraindicated
- Amifostine + Hydrochlorothiazide-lisinopril Major
- Amiloride + Hydrochlorothiazide-lisinopril Major
- Benazepril + Hydrochlorothiazide-lisinopril Major
- Bendroflumethiazide + Hydrochlorothiazide-lisinopril Major
Frequently asked questions
Can I take Hydrochlorothiazide-lisinopril with Sulfamethoxazole?
MediHelp rates the interaction as moderate. Hydrochlorothiazide-lisinopril and Sulfamethoxazole 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. Thiazide diuretics can cause hyponatremia, and sulfamethoxazole-trimethoprim has also been associated with low sodium. Combined with an ACE inhibitor, the trimethoprim component additionally raises the risk of hyperkalemia and renal impairment, especially in older patients.
How serious is the interaction between Hydrochlorothiazide-lisinopril and Sulfamethoxazole?
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 sodium, potassium and creatinine within the first week of co-trimoxazole therapy. Consider an alternative antibiotic in patients with renal impairment or a high baseline hyperkalemia risk.
What other medicines interact with Hydrochlorothiazide-lisinopril?
MediHelp also lists interactions of Hydrochlorothiazide-lisinopril with, for example, Dofetilide, Sacubitril / valsartan, Amifostine. The full list is on the Hydrochlorothiazide-lisinopril page.
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