You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Hydralazine and explain in detail?
Hydralazine, sold under the brand name Apresoline among others, is a medication used to treat high blood pressure and heart failure. This includes high blood pressure in pregnancy and very high blood pressure resulting in symptoms. It has been found to be particularly useful in heart failure, together with isosorbide dinitrate, for treatment of people of African descent. It is given by mouth or by injection into a vein. Effects usually begin around 15 minutes and last up to six hours.Common side effects include headache and fast heart rate. It is not recommended in people with coronary artery disease or in those with rheumatic heart disease that affects the mitral valve. In those with kidney disease a low dose is recommended. Hydralazine is in the vasodilator family of medications, so it is believed to work by causing the dilation of blood vessels.Hydralazine was discovered while scientists at Ciba were looking for a treatment for malaria. It was patented in 1949. It is on the World Health Organizations List of Essential Medicines.  In 2019, it was the 99th most commonly prescribed medication in the United States, with more than 6 million prescriptions. Hydralazine has an adverse drug event of inducing drug-induced lupus and this drugs use is declining with more prescribers prescribing calcium channel blockers.

Medical use
Hydralazine is not used as a primary drug for treating hypertension because it elicits a reflex sympathetic stimulation of the heart (the baroreceptor reflex). The sympathetic stimulation may increase heart rate and cardiac output, and in people with coronary artery disease may cause angina pectoris or myocardial infarction. Hydralazine may also increase plasma renin concentration, resulting in fluid retention. To prevent these undesirable side effects, hydralazine is usually prescribed in combination with a beta blocker (e.g., propranolol) and a diuretic. Beta-blockers licensed to treat heart failure in the UK include bisoprolol, carvedilol, and nebivolol.Hydralazine is used to treat severe hypertension, but is not a first-line therapy for essential hypertension. Hydralazine is often used to treat hypertension in pregnancy, though, with either labetalol and/or methyldopa.Hydralazine is commonly used in combination with isosorbide dinitrate for the treatment of congestive heart failure in self-identified African-American populations. This preparation, isosorbide dinitrate/hydralazine, was the first race-based prescription drug.It should not be used in people who have tachycardia, heart failure, constrictive pericarditis, lupus, a dissecting aortic aneurysm, or porphyria.

Adverse effects
Prolonged treatment may cause a syndrome similar to lupus, which can become fatal if the symptoms are not noticed and drug treatment stopped