Hydralazine hydrochloride is a medication classified as a vasodilator. It is primarily used to treat hypertension (high blood pressure) by relaxing and dilating the blood vessels, which helps to lower blood pressure. Hydralazine hydrochloride works by directly relaxing the smooth muscles in the walls of blood vessels, resulting in increased blood flow and reduced resistance in the arteries. It is typically prescribed when other antihypertensive medications are not well-tolerated or effective. Hydralazine hydrochloride is usually taken orally in tablet form and is available in different strengths. It is important to follow the dosage instructions provided by a healthcare professional and to regularly monitor blood pressure while taking this medication. Common side effects may include headaches, dizziness, flushing, and nausea. Close medical supervision is necessary during treatment with hydralazine hydrochloride.