A fixed-dose combination (FDC) antihypertensive medication containing an ACE inhibitor (Lisinopril) and a thiazide diuretic (Hydrochlorothiazide). It provides synergistic blood pressure lowering by reducing peripheral vascular resistance and decreasing plasma volume. This combination is widely used in the Indian market for essential hypertension, especially in patients requiring more than one drug for adequate control.
Adult: One tablet (Lisinopril 5mg + HCTZ 12.5mg) orally once daily, preferably in the morning. Dose may be titrated up to a maximum of Lisinopril 20mg + HCTZ 25mg after 2-3 weeks based on response.
Note: Take orally with or without food. Swallow whole with a glass of water. Maintain adequate fluid intake unless contraindicated. Best taken in the morning to avoid nocturia. Do not skip doses.
Lisinopril competitively inhibits Angiotensin Converting Enzyme (ACE), preventing the conversion of angiotensin I to angiotensin II, a potent vasoconstrictor. This leads to vasodilation, decreased aldosterone secretion (reducing sodium and water retention), and reduced bradykinin degradation. Hydrochlorothiazide inhibits sodium-chloride symport in the distal convoluted tubule of the nephron, promoting excretion of sodium, chloride, and water, thereby reducing plasma volume and extracellular fluid volume. The combination results in additive reduction of blood pressure through complementary mechanisms.
Pregnancy: CONTRANDICATED in second and third trimesters (ACE inhibitors can cause injury and death to the developing fetus, including oligohydramnios, fetal hypocalvaria, renal failure, and death). Discontinue as soon as pregnancy is detected. Category D (US FDA).
Driving: Dizziness, lightheadedness, or syncope may occur, especially during initiation of therapy. Patients should be cautioned about driving or operating machinery until their response is known.
| Potassium supplements / Potassium-sparing diuretics (e.g., Spironolactone, Amiloride) | Increased risk of severe hyperkalemia | Major |
| NSAIDs (e.g., Ibuprofen, Diclofenac) | Reduced antihypertensive effect; increased risk of renal impairment | Major |
| Lithium | Increased lithium levels and toxicity (reduced renal clearance) | Major |
| Antidiabetic drugs (Insulin, Sulfonylureas) | HCTZ may decrease glucose tolerance, requiring dose adjustment | Moderate |
| Other antihypertensives / Vasodilators | Additive hypotensive effect | Moderate |
| Allopurinol | Increased risk of hypersensitivity reactions | Moderate |
| Cholestyramine / Colestipol | Reduced absorption of HCTZ | Moderate |
| Alcohol, Barbiturates, Narcotics | Potentiation of orthostatic hypotension | Moderate |
Same composition (Lisinopril (5mg) + Hydrochlorothiazide (12.5mg)), different brands: