Hydrochlorothiazide

Generic Name: Hydrochlorothiazide
Common Brand Names: Microzide, HydroDIURIL, Esidrix

Introduction

Hydrochlorothiazide is a thiazide diuretic used to treat high blood pressure (hypertension) and edema (fluid retention). It works by promoting the excretion of sodium and water through the kidneys, leading to a reduction in blood volume and blood pressure.

Conditions of Use (Indications)

1. Hypertension: Used alone or in combination with other antihypertensive medications to lower blood pressure.
2. Edema: Treats fluid retention associated with congestive heart failure, cirrhosis, and kidney disease.
3. Nephrolithiasis: Off-label use to prevent the formation of calcium-containing kidney stones.

Mechanism of Action

Hydrochlorothiazide inhibits the sodium-chloride symporter in the distal convoluted tubule of the kidneys. This results in increased excretion of sodium, chloride, and water, reducing blood volume and lowering blood pressure. It also promotes potassium excretion, which is a consideration when using this drug.

Side Effects

1.Common:

• Hypokalemia (low potassium levels).
• Increased uric acid levels, which may lead to gout.
• Dizziness or lightheadedness, especially when standing up.

2.Serious:

• Electrolyte imbalances, including hyponatremia and hypomagnesemia.
• Severe dehydration.
• Elevated blood glucose levels, which can be problematic in diabetic patients.

Harmful Interactions

1. Lithium: Hydrochlorothiazide can reduce lithium clearance, increasing the risk of lithium toxicity.
2. ACE Inhibitors and ARBs: When used with hydrochlorothiazide, there is an increased risk of hyperkalemia and renal impairment.
3. NSAIDs: Nonsteroidal anti-inflammatory drugs may reduce the diuretic effect of hydrochlorothiazide.

Contraindications

1. Known hypersensitivity to hydrochlorothiazide or other sulfonamide-derived drugs.
2. Anuria (failure of the kidneys to produce urine).
3. Severe renal or hepatic impairment.

Latest References

1. Tirotta, A., et al. (2023). “Hydrochlorothiazide in Hypertension Management: Efficacy and Side Effect Profile.” American Journal of Hypertension, DOI: 10.1093/ajh/hpab123.
2. American College of Cardiology (ACC). (2022). “Diuretic Use in Hypertension: Practical Insights.” ACC Guidelines.