Hydralazine And Hydrochlorothiazide

Drug Overview

The combination of Hydralazine and Hydrochlorothiazide is a dual-action antihypertensive medication primarily used to control hypertension (primary hypertension) and related cardiovascular diseases. This medication combines the mechanisms of vasodilation and diuresis, lowering vascular resistance through vasodilation while promoting water and salt excretion to achieve stable blood pressure.

This drug is typically used for patients whose blood pressure cannot be effectively controlled with a single agent or in severe hypertension cases requiring rapid volume reduction. Its combination can reduce the high doses of single components, lowering the risk of side effects, but must be used strictly according to a physician’s instructions.

Brand Names and Generic Name

The generic name of this combination drug is Hydralazine and Hydrochlorothiazide. Common brand names include “Apo-Hydralazine HCTZ” and “Hytiazide,” among others. Different regions may have different trade names. Patients should refer to the medication label and confirm whether the active ingredients include these two components.

Drug Classification

This medication is a fixed-dose combination of a vasodilator and a diuretic, specifically classified as:

Hydralazine: Peripheral arterial vasodilator (vasodilator class)
Hydrochlorothiazide: Thiazide diuretic

This combination employs a dual mechanism of lowering blood pressure by directly reducing vascular resistance and decreasing circulating fluid volume.

Indications

Main indications include:

Primary hypertension (first-line or adjunct therapy)
Hypertensive patients with edema
Patients unresponsive to other antihypertensive medications

In some cases, it may also be used for blood pressure abnormalities associated with heart failure.

Common Side Effects

Mild side effects: Dizziness, fatigue, muscle aches, nocturia, mild hypotension (possible dizziness upon standing).

Serious side effects: If any of the following symptoms occur, discontinue medication immediately and seek medical attention:

Skin abnormalities such as redness or hives
Shortness of breath or chest pain
Weak limbs or speech difficulties
Severe edema or oliguria

Warnings and Precautions

Contraindications include:

Allergy to any component
Severe renal impairment
Hyperkalemia or metabolic acidosis

This medication is FDA pregnancy category C. Use during pregnancy should involve a risk-benefit assessment, and it should be avoided during breastfeeding.

Drug Interactions

Special caution is required when combined with:

Other antihypertensives (such as beta-blockers, ACE inhibitors) which may have additive effects
Insulin or oral hypoglycemic agents which may affect blood glucose control
Non-steroidal anti-inflammatory drugs (NSAIDs) which may reduce diuretic efficacy

Consult a physician before taking herbal medicines or supplements (such as potassium tablets).

Dosage and Administration

The usual initial dose is 1-2 times daily, with specific dosage adjusted based on patient age and liver/kidney function. It should be taken with meals to reduce gastrointestinal discomfort, but the tablets should not be chewed or opened. The physician may gradually adjust the dose based on blood pressure monitoring results.

Do not increase or decrease the dose on your own. If blood pressure control is inadequate, return to the clinic promptly. Do not self-increase the dose to avoid hypotensive crises.

Missed Dose Management

If a dose is missed and more than 4 hours remain before the next scheduled dose, take it as soon as possible. If it is close to the next dose, skip the missed dose and resume normal schedule. Do not double the dose.

Overdose Management

An overdose may cause severe hypotension, syncope, electrolyte disturbances. Seek immediate medical attention. Intravenous fluids or vasopressors may be required. Keep medication out of reach of children to prevent accidental ingestion.

Frequently Asked Questions

What tests should patients regularly undergo while taking this medication?

Patients should regularly monitor blood pressure, serum potassium, renal function, and hemoglobin levels. Hydrochlorothiazide may cause hypokalemia or changes in renal function, while Hydralazine may affect blood cell systems. Blood and urine tests are recommended every 3-6 months, with frequency adjusted according to physician instructions.

Should medication be taken with food? How should missed doses be handled?

It is recommended to take the medication with meals to reduce gastrointestinal discomfort, but at a fixed time. If a dose is missed, take it as soon as remembered. If close to the next dose, skip the missed dose. Do not double doses. If long-term missed doses cause blood pressure fluctuations, consult your physician promptly for medication adjustment.

How to manage side effects like dizziness or muscle pain during use?

Dizziness may result from rapid blood pressure reduction. Move slowly when standing and ensure a safe environment. If dizziness persists or worsens, measure blood pressure and adjust posture. Muscle pain accompanied by fever or weakness may be due to metabolic changes caused by Hydrochlorothiazide and should be reported to a physician immediately.

What interactions should be considered when combined with other antihypertensives or supplements?

Combining with beta-blockers or calcium channel blockers may cause excessive blood pressure lowering. Avoid concurrent use with potassium supplements or potassium-sparing diuretics to prevent hyperkalemia. Non-steroidal anti-inflammatory drugs may reduce antihypertensive effects. Inform your doctor of all medications being used.

How should diet be adjusted during treatment to reduce side effects?

Adopt a low-sodium diet to enhance antihypertensive effects, and consume potassium-rich foods (such as bananas and spinach) to counteract potassium loss from diuretics. Avoid excessive alcohol intake to prevent worsening dizziness or palpitations. If dehydration or abnormal urination occurs, adjust fluid intake and inform your doctor.

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