Intravenous High Blood Pressure Medication: A Look at Usage, Side Effects, and Risks

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A Look at Hypertension

Millions of Americans suffer from high blood pressure, or hypertension. For most people, a combination of oral medications will control the blood pressure. However, hospitalized patients may have extremely high blood pressure which requires quick intervention to lower it and prevent organ damage. A patient with severe hypertension that does not respond to oral medications may be admitted to the intensive care unit (ICU) for close blood pressure monitoring and intravenous high blood pressure medication to lower pressure. The Mayo Clinic points out several complications of untreated hypertension, including atherosclerosis, coronary artery disease, heart failure, stroke, kidney damage, eye damage, and bone loss.

Indications for Use

The physician may order IV medication to treat hypertension that does not respond to oral medication or in a hypertensive emergency, in which there is the risk of organ damage. These medications can be given as a one-time dose, known as an IV push, or be given as a drip, which is titrated to keep blood pressure between specific parameters. An IV drip is given for long-term management when an IV push dose wears off quickly. Since they do not have to dissolve in the stomach and be absorbed into the bloodstream, they are effective much quicker, with some acting almost immediately. For this article, we will look at the most commonly given IV hypertension medications.


These are familiar to almost anyone with hypertension. They make the body increase urine production, thereby decreasing fluid volume in the bloodstream and lowering blood pressure. They are the oldest antihypertensives and are usually given in pill form. Common drugs include Lasix, Demadex, and Aldactone. Patients requiring IV diuretics are most commonly given Lasix or Demadex IV push. If a drip is needed, Lasix is commonly ordered and administered in an ICU.

Side effects include frequent urination and increased potassium excretion with Lasix and Demadex, which may require monitoring potassium levels or taking potassium supplements. Other less common side effects may include hypotension (low blood pressure), muscle cramps, and dehydration. Diuretics are contraindicated in hypersensitivity. Aldactone should not be given to patients with elevated potassium, or to pregnant or lactating women. Safety has not been established with children. Lasix is contraindicated in hypersensitivity, hepatic coma, or uncorrected electrolyte imbalances.


Labetalol is the only beta-blocker useful to treat hypertensive emergencies. It may also be given to patients with active coronary disease as it does not increase the heart rate. It is contraindicated in patients with pulmonary edema, uncompensated congestive heart failure, cardiogenic shock, heart block, or low heart rate. Side effects include hypotension, weakness, and fatigue.


Hydralazine is a vasodilator, meaning it relaxes the blood vessels, given in moderate to severe hypertension. It is typically ordered as an IV push to be given if a patient’s blood pressure goes above a predetermined limit. It is contraindicated in hypersensitivity and should be used cautiously in cardiovascular or cerebrovascular disease, severe kidney or liver disease, and in pregnant or lactating women, and children. Side effects include rapid heart rate, sodium retention, dizziness, and headache.


Nipride is considered to be the most effective IV medication for most hypertensive emergencies. It relaxes both veins and arteries and begins working within seconds. It is contraindicated in hypersensitivity. Side effects include abdominal pain, nausea, headache, and dizziness. It should be used with caution in patients with liver or kidney disease, as cyanide toxicity may result. Nipride should be kept wrapped in foil to prevent exposure to light. Ringing in the ears, confusion, weakness, and breath odor similar to almonds indicate cyanide toxicity and should be reported immediately. Safety in pregnant or lactating women has not been established.


Cardiology Channel-


The Mayo Clinic-