SIDE EFFECTS: Headache, pounding/fast heartbeat, loss of appetite, nausea, vomiting, diarrhea, or dizziness may occur as your body adjusts to the medication. If any of these effects persist or worsen, tell your doctor or pharmacist promptly. To reduce the risk of dizziness, get up slowly when rising from a sitting or lying position. Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects. This medication may rarely cause nerve problems. Tell your doctor promptly if you experience numbness or tingling. Your doctor may recommend a vitamin B6 supplement (pyridoxine). Tell your doctor right away if any of these unlikely but serious side effects occur: severe tiredness, aching/swollen joints, rash on nose and cheeks, swollen glands, signs of kidney problems (such as change in the amount of urine, bloody/pink urine), signs of infection (such as fever, chills, persistent sore throat), easy bruising/bleeding. Seek immediate medical attention if this rare but serious side effect occurs: chest/jaw/left arm pain. A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any of the following symptoms of a serious allergic reaction: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing. This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist. In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch. In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

PRECAUTIONS: Before taking hydralazine, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details. This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist if you have: a certain heart condition (coronary artery disease), a certain heart valve problem (rheumatic heart disease of the mitral valve). Before using this medication, tell your doctor or pharmacist your medical history, especially of: blood vessel problems, previous stroke, kidney problems. This drug may make you dizzy. Alcohol or marijuana can make you more dizzy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana. Before having surgery, tell your doctor or dentist that you are taking this medication. Older adults may be more sensitive to the side effects of this medication, especially dizziness, which can increase the risk of falls. This medication should be used only when clearly needed during pregnancy. Discuss the risks and benefits with your doctor. This medication passes into breast milk, but is unlikely to harm a nursing infant. Consult your doctor before breast-feeding.

DRUG INTERACTIONS: Your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor or pharmacist first. Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use, especially of: MAO inhibitors (isocarboxazid, linezolid, methylene blue, moclobemide, phenelzine, procarbazine, rasagiline, safinamide, selegiline, tranylcypromine). Some products have ingredients that could raise your heart rate or blood pressure or worsen your heart failure. Tell your pharmacist what products you are using, and ask how to use them safely (especially cough-and-cold products, diet aids, or NSAIDs such as ibuprofen/naproxen). This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist.

OVERDOSE: If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: severe dizziness, fainting, flushing, chest/jaw/left arm pain, irregular heartbeat.