Hydralazine is a generic prescription blood pressure drug, but it’s usually not a first choice for treatment. Healthcare providers more commonly use it when other drugs are not effective enough, or in certain emergency situations. Available as a tablet or injection, hydralazine doses typically need to be taken or administered three to four times a day.
Check our best Hydralazine prices
No brand-name versions
Hydralazine HCl
Treats high blood pressure and hypertensive emergencies
Antihypertensive, peripheral vasodilator
Tablet, injection
By mouth, injection
Healthcare professionals use hydralazine to manage patients with high blood pressure, especially when other drugs are not effective enough. They also use it to treat blood pressure emergencies, including hypertensive crisis, eclampsia, or preeclampsia. Hydralazine is commonly used off-label to treat heart failure, often in combination with the medicine isosorbide dinitrate.
Take hydralazine exactly as directed by your healthcare provider, and keep all appointments for follow-up and labs.
Since hydralazine is typically taken 3 or 4 times daily, you can use a smartphone or alarm to remember to take your doses.
You can take hydralazine with or without food, but it is best to take it the same way each time—always with food, or always without food.
If you have any questions or concerns, consult your healthcare provider for medical advice.
Tablets
10 mg
25 mg
50 mg
100 mg
Injection
20 mg/mL
Doses may vary, and these are general guidelines. Always follow the dosing directions given by your healthcare provider.
For high blood pressure (oral): Starting dose is 10 mg by mouth four times daily for two to four days, then 25 mg four times daily for the balance of the first week, then may increase to 50 mg four times daily if more blood pressure control is needed. The usual dose ranges from 100 to 200 mg per day in two to four doses.
For high blood pressure (injection): 10–20 mg intravenous or 10–50 mg intramuscular injection every four to six hours as needed; healthcare provider will switch to oral form as soon as possible
For heart failure (off-label): 25–50 mg taken three or four times daily; healthcare provider will increase as required. For heart failure, hydralazine is typically taken along with other medications.
hydrALAZINE HCl
100mg tablet
hydrALAZINE HCl
10mg tablet
hydrALAZINE HCl
25mg tablet
hydrALAZINE HCl
50mg tablet
hydrALAZINE HCl
1ml of 20mg/ml vial
Take this medication as prescribed. The dose may need to be changed several times to find what works best for you.
Doses are taken three to four times per day. Use an alarm or smartphone to help you remember to take doses.
Take doses at the same time every day.
Hydralazine may be taken with or without food, but must be taken that way every time.
Hydralazine injections are administered by a healthcare professional.
Store hydralazine tablets at room temperature out of the reach of children.
If you miss a dose, take it as soon as you remember.
If it is almost time for the next dose, skip the missed dose and take your next dose at the regular time.
Do not take two doses to make up for a missed dose.
This medicine is not right for everyone. Before taking hydralazine, tell your healthcare provider about your medical history and medical conditions.
Do not use it if you have had an allergic reaction to hydralazine or if you have:
Coronary artery disease (CAD)
Rheumatic heart disease
Tell any doctor or other healthcare provider who treats you that you are using this medicine.
The prescriber may recommend regular visits and lab tests to monitor the effectiveness and side effects of this treatment. Keep all appointments.
Tell the prescriber if you are pregnant, breastfeeding, or have:
Kidney disease
Heart disease
Chest pain (angina)
Heart rhythm irregularities
Blood vessel disease
Low blood pressure
Lupus
Peripheral neuritis (tingling and numbness)
A history of heart attack or stroke
Hydralazine can cause serious problems, including:
Heart rhythm abnormalities
Chest pain
Nerve problems including numbness and tingling
Lupus-like symptoms
This medicine may lower your blood pressure too much and cause dizziness, lightheadedness, or fainting. Do not drive or do anything else that could be dangerous until you know how this medicine affects you.
Check with your healthcare provider about alcohol use while taking hydralazine, as alcohol can worsen some of the side effects of this medicine.
To avoid drug interactions, tell the prescribing healthcare provider about all prescription drugs, over-the-counter medicines, vitamins, and supplements being taken before starting hydralazine, particularly:
Other drugs that lower blood pressure
Monoamine oxidase inhibitors (MAOIs)
Serious side effects
Get emergency medical help right away if you notice any signs or symptoms of a possible serious side effect, including:
Fast, pounding, or uneven heartbeat
Chest pain (which may spread to your arms, jaw, back, or neck), trouble breathing, unusual sweating, faintness
Blistering, peeling, red skin rash
Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
Call your healthcare provider right away if you have any of the following symptoms:
Fatigue, fever, muscle pain, joint pain
Change in how much or how often you urinate
Numbness, tingling, or burning pain in your hands, arms, legs, or feet
Common side effects
Nausea, vomiting, diarrhea
Loss of appetite
Headache
Consult your pharmacist or other healthcare provider for more information about adverse effects of hydralazine.
2020 clinical management guidelines for obstetrician-gynecologists: Gestational hypertension and preeclampsia, The American College of Obstetricians and Gynecologists (ACOG) (2020)
Apresoline drug summary, Prescriber’s Digital Reference (PDR)
Hydralazine hydrochloride injection prescribing information, DailyMed (NIH National Library of Medicine) (2022)
Hydralazine hydrochloride tablet prescribing information, DailyMed (NIH National Library of Medicine) (2020)
Hydralazine, StatPearls (2023)
Hydralazine, MedlinePlus (2017)
After receiving her doctorate from the University of Pittsburgh School of Pharmacy, Karen Berger, Pharm.D., has worked in both chain and independent community pharmacies. She currently works at an independent pharmacy in New Jersey. Dr. Berger enjoys helping patients understand medical conditions and medications—both in person as a pharmacist, and online as a medical writer and reviewer.
...SingleCare es un servicio de descuentos para medicamentos recetados que ofrece cupones gratuitos para miles de medicamentos. Puedes usarlo aun si tienes seguro, Medicare, Medicaid o no, pero no se puede combinar con el seguro.
SingleCare ofrece transparencia al mostrar los precios de medicamentos para que puedas comparar descuentos en farmacias cerca de ti. Visita singlecare.com para encontrar descuentos en medicamentos, información útil sobre tu receta médica y recursos que te ayudan a tomar decisiones informadas sobre tu salud.
Los ahorros en recetas varían según la receta médica y la farmacia, y pueden alcanzar hasta un 80% de descuento sobre el precio en efectivo. Este es un plan de descuento de recetas médicas. NO es un seguro ni un plan de medicamentos de Medicare. El rango de descuentos para las recetas médicas que se brindan bajo este plan, dependerá de la receta y la farmacia donde se adquiera la receta y puede otorgarse hasta un 80% de descuento sobre el precio en efectivo. Usted es el único responsable de pagar sus recetas en la farmacia autorizada al momento que reciba el servicio, sin embargo, tendrá el derecho a un descuento por parte de la farmacia de acuerdo con el Programa de Tarifas de Descuento que negoció previamente. Towers Administrators LLC (que opera como “SingleCare Administrators”) es la organización autorizada del plan de descuento de recetas médicas ubicada en 4510 Cox Road, Suite 11, Glen Allen, VA 23060. SingleCare Services LLC (“SingleCare”) es la comercializadora del plan de descuento de prescripciones médicas que incluye su sitio web www.singlecare.com. Como información adicional se incluye una lista actualizada de farmacias participantes, así como también asistencia para cualquier problema relacionado con este plan de descuento de prescripciones médicas, comunícate de forma gratuita con el Servicio de Atención al Cliente al 844-234-3057, las 24 horas, los 7 días de la semana (excepto los días festivos). Al utilizar la aplicación o la tarjeta de descuento para recetas médicas de SingleCare acepta todos los Términos y Condiciones, para más información visita: https://www.singlecare.com/es/terminos-y-condiciones. Los nombres, logotipos, marcas y otras marcas comerciales de las farmacias son propiedad exclusiva de sus respectivos dueños.
Los artículos del blog no constituyen asesoramiento médico. Su propósito es brindar información general y no sustituyen el asesoramiento, diagnóstico ni tratamiento médico profesional. Si tiene alguna pregunta sobre una afección médica, consulte siempre a su médico u otro profesional de la salud cualificado. Si cree tener una emergencia médica, llame inmediatamente a su médico o al 911.
© 2025 SingleCare Administrators. Todos los derechos reservados
© 2025 SingleCare Administrators. Todos los derechos reservados