Hydrochlorothiazide (HCTZ) is a type of thiazide diuretic often used to treat high blood pressure and fluid retention (edema). It works by increasing urine output, which helps the body get rid of excess sodium and water, thereby reducing fluid buildup and lowering blood pressure.

Mechanisms of Action
HCTZ works by blocking sodium reabsorption in the distal tubules of the kidneys. This inhibition leads to the increased excretion of sodium, chloride, and water, which decreases blood volume. As a result, it helps lower blood pressure and reduce fluid buildup in the body.

Contraindications & Precautions
Contraindications: Anuria, severe kidney or liver disease, hypersensitivity to HCTZ or sulfonamides.
Precautions: Use with caution in patients with gout, diabetes, or electrolyte imbalances (e.g., low potassium or sodium).

Interactions
⦁ ACE inhibitors/ARBs: Increased risk of hyperkalemia (high potassium).

Adverse Reactions / Side Effects
⦁ Common: Dizziness, headache, increased urination, low potassium.
⦁ Serious: Electrolyte imbalances, gout attacks, kidney dysfunction, and severe dehydration.

Pregnancy & Breastfeeding
⦁ Pregnancy: Not recommended during the first trimester.
⦁ Breastfeeding: Use with caution as HCTZ passes into breast milk.

Store this medication at 68°F to 77°F (20°C to 25°C) and away from heat, moisture and light. Keep all medicine out of the reach of children. Throw away any unused medicine after the beyond use date. Do not flush unused medications or pour down a sink or drain.

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