Hydralazine belongs to vasodilator group of medications that function through relaxation of the muscles located inside blood vessels to assist them with dilating (widening).
Hydrazine achieves that affect by influencing calcium movement within blood vessels.
Calcium is important for muscle to contract properly and hereby any changes in calcium movement may result in gradual relaxation of muscles located inside blood vessels.
Hydralazine is selective when it comes to small arteries (i.e. arterioles).
As result, that reduces arterial blood pressure, as well as peripheral vascular resistance and assists blood to flow easily in arteries and veins.
Likewise, Hydralazine has the main function to treat hypertension (i.e. high blood pressure).
Besides that, Hydralazine shows positive results in treatment of congestive heart failure (CHF).
To achieve a desired effect, Hydralazine can be combined with isosorbide dinitrate (e.g. Isordil, Dilatrate-SR, Isordil Titradose) as an alternative solution for patients who are unable to tolerate ACE inhibitors.
Hydralazine can also be applied as an antihypertensive agent to treat hypertension among pregnancy.
Injectable or parenteral hydralazine is prescribed for pregnant patients with severally high blood pressure.
However, pregnant patients are required to undergo a consultation with a healthcare specialist in order to ensure it is really safe for them to take Hydralazine.
Things you need to consider prior to taking Hydralazine
There are several important factors and/or allergies you need to consider and highlight to your healthcare provider prior to deciding on initiating Hydralazine treatment
You should not use hydralazine if you are allergic to it, or if you have:
- Coronary artery disease;
- Rheumatic heart disease having a negative effect on the mitral valve.
In addition, please make sure to highlight the previous history of:
- Systemic Lupus Erythematosus;
- Kidney disease;
- Angina (severe chest pain).
The effects of Hydralazine on an unborn baby are not clear yet, hence it is very important that you inform your doctor if you are pregnant or have plans to become pregnant soon.
There is possibility that Hydralazine passes into breast milk, hence let your doctor know if you are breast-feeding at the moment of treatment.
In addition, please also take note that Hydralazine is not approved for patients younger than 18 years old.
Possible Side Effects Caused by Hydralazine
Hydralazine may interact with your body during the treatment process and that may result in the following common side effects:
- Pain in chest, increased heartbeat rate;
- Continuous headache;
- Vomiting, nausea, appetite loss, diarrhea.
However, if you observe any signs of allergic reaction, like swollen lips, face, throat or tongue, and/or one of the following, please do not hesitate to contact your healthcare provider for immediate assistance:
- Chest pressure or ache, spreading to shoulders or jaw;
- Increased and/or pounding heartbeats;
- A feeling of light-headedness/feeling as if you are about to pass out;
- Tingling sensations, numbness, or burning pain spreading in feet or hands;
- Pain or difficulties during urination;
- Reduced or no urination;
- Lupus-like syndrome –pain/swelling in joints accompanied by fever, muscle/chest pain, swollen glands, repeated vomiting, abnormal thoughts or attitude, patchy color of skin etc.
How to take Hydralazine?
It is best that you abide to all directions listed in your prescription.
Do not increase or decrease the medicine dosage and do not take it longer than specified in prescription.
Throughout the treatment period, you are also required to check your blood pressure and perform blood tests on a regular basis.
Keep taking Hydralazine as prescribed, even if you already start feeling alright.
Usually, high blood pressure shows no symptoms.
Make sure Hydralazine is stored at room temperature away from kids reach, as well as excessive heat and moisture.
What is the best dosage of Hydralazine that I should follow?
Adult patients with Hypertension should follow the following dosage, provided the healthcare provider agrees with it:
- Initiate the treatment with a low dose and gradually increase the dosage depending on patient’s response;
- The general recommended dosage is 10 mg to be taken orally 4 times a day during first 2-4 days, followed by increase in dosage up to 25 mg 4 times a day for the remaining days of the first treatment week;
- Second and subsequent weeks require increase in dosage up to 50 mg 4 times a day (gradually increase the dosage by 10-25 mg/dose for each 2-5 days);
- The highest daily dosage based on clinical studies, is 300 mg.
Patients suffering from Congestive Heart Failure should follow the following regimen:
- The initial dosage is 10-25 mg to be taken orally 3-4 times a day;
- The normal dosage is 225-300 mg to be taken daily and divided into 3-4 doses;
- For pediatric hypertensive emergency cases, the recommended dosage is 0.5 mg/Kg IV every 4 hours.
In case, if you have missed a dose, take it as soon as you have discovered that.
You may skip the missed dose, provided it is almost time for the next dose.
Avoid taking extra dose just to make up the missed dose.
Seek an emergency medical assistance in case if you observe any overdose symptoms, like: increased heartbeat, warmth or tingling sensations underneath skin, chest ache, sudden fainting etc.
The list of supplements or medications that may interact with Hydralazine
Sympathomimetics listed below, may reduce the effectiveness of hydralazine:
- Dobutamine (Dobutrex);
- Norepinephrine (Levophed);
- Dopamine (Intropin);
- Metaraminol (Aramine);
- Epinephrine (Adrenalin);
- Ephedra (Ma Huang);
Hereby, co-administration of the abovementioned meds may result in reduction of the anti-hypertensive effects caused by hydralazine treatment
In addition, inform your doctor regarding all medications you are currently taking, especially if the list includes:
- Diazoxide (medication that is injected to treat blood pressure);
- MAO inhibitor – isocarboxazid, methylene blue injection, linezolid, rasagiline, phenelzine, tranylcypromine, selegiline and others.
The list above is not fully complete.
There are other drugs that can interact with hydralazine, like over-the-counter and prescription medications, herbal products and vitamins.
Not all possible interactions are included in this medication guide.
To get the complete list, consult with your doctor or get the detailed medication description from manufacturer.
It is very important to understand this drug interaction with other medications in order to avoid any unwanted effects and ensure the entire treatment process is smooth and effective.
Is it safe for pregnant or breastfeeding patients to take Hydralazine?
Hydralazine is under FDA pregnancy risk category C (reproduction studies conducted among animals have confirmed an adverse effect exerted on the fetus; there are no confirmed studies conducted among human patients), hence any treatment should be performed only if the potential benefits can justify the anticipated risk that may be caused to the fetus and it is fully approved by the healthcare provider.
Generally, Hydralazine is applied for treatment of high blood pressure experienced during pregnancy.
Since Hydralazine can be excreted in breast milk, female patients who are breastfeeding, should consult their doctor first to confirm, whether the treatment is really necessary.
Likewise, as a pregnant or breastfeeding patient, it is best that you take this with utmost responsibility in order not to cause any harm to yourself or to your child.