What is Angiotensin II Acetate used for?

Introduction to Angiotensin II Acetate:

Angiotensin II Acetate, also known by its trade name Giapreza, is a synthetic form of the naturally occurring peptide hormone angiotensin II. It is a potent vasoconstrictor used primarily to increase blood pressure in adults with septic or other distributive shock. This drug is classified as a vasoactive agent and is typically utilized in intensive care units (ICUs). Approved by the U.S. Food and Drug Administration (FDA) in 2017, Angiotensin II Acetate was developed through extensive research and clinical trials conducted by La Jolla Pharmaceutical Company. The drug targets the angiotensin II type 1 receptor (AT1R), which plays a crucial role in regulating blood pressure and fluid balance. The primary indication for Angiotensin II Acetate is to increase blood pressure in patients who are experiencing hypotension despite adequate fluid resuscitation and the use of conventional vasopressors like norepinephrine or dopamine.

Angiotensin II Acetate Mechanism of Action:

The primary mechanism of action of Angiotensin II Acetate involves its interaction with the angiotensin II type 1 receptor (AT1R). When Angiotensin II binds to AT1R, it triggers a cascade of intracellular signaling pathways that result in the constriction of blood vessels (vasoconstriction). This vasoconstriction increases vascular resistance, which in turn elevates blood pressure. Additionally, Angiotensin II stimulates the release of aldosterone from the adrenal glands, promoting sodium and water retention by the kidneys. This fluid retention further contributes to increased blood volume and blood pressure. Angiotensin II also induces the release of catecholamines like norepinephrine from sympathetic nerve endings, which further potentiates vascular tone and cardiac output. Therefore, Angiotensin II Acetate acts at multiple levels to sustain and elevate blood pressure in critically ill patients.

How to Use Angiotensin II Acetate:

Angiotensin II Acetate is administered intravenously, and it is typically given as a continuous infusion due to its short half-life. The initial recommended dose is 20 nanograms (ng) per kilogram (kg) per minute, which can be titrated based on the patient's response and clinical status. The onset of action is rapid, often within minutes, which makes it highly effective in acute settings where immediate blood pressure elevation is necessary. The dosing may be increased by increments of up to 15 ng/kg/min every 5 minutes as needed to achieve the desired target blood pressure, up to a maximum dose of 80 ng/kg/min during the first 3 hours of treatment. After the initial period, the maximum dose should not exceed 40 ng/kg/min. The patient's blood pressure and clinical parameters should be closely monitored throughout the administration to ensure efficacy and safety. The infusion should be adjusted or discontinued based on the patient's hemodynamic response and any potential side effects.

What is Angiotensin II Acetate Side Effects:

Like any medication, Angiotensin II Acetate is not without potential side effects. The most common side effects observed include thromboembolic events such as deep vein thrombosis and arterial thrombosis, which may occur due to increased blood pressure and vascular resistance. Other side effects include tachycardia, peripheral ischemia, and acidosis. Due to the risk of severe thrombotic events, prophylactic anticoagulation is recommended unless contraindicated. Patients with known hypersensitivity to Angiotensin II or any of its components should not use this medication. Additionally, caution should be exercised in patients with conditions that predispose them to thromboembolism, such as those with a history of myocardial infarction, stroke, or severe peripheral artery disease.

What Other Drugs Will Affect Angiotensin II Acetate:

Several drugs can interact with Angiotensin II Acetate, potentially affecting its efficacy and safety profile. Concomitant use of other vasopressors, such as norepinephrine, epinephrine, or vasopressin, may have additive effects on blood pressure and should be closely monitored to avoid excessive hypertension. Nonsteroidal anti-inflammatory drugs (NSAIDs) and cyclooxygenase-2 (COX-2) inhibitors may attenuate the vasoconstrictive effects of Angiotensin II, potentially reducing its efficacy. Angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) may also interfere with the action of Angiotensin II Acetate, as they oppose the renin-angiotensin-aldosterone system (RAAS). Additionally, corticosteroids may enhance the pressor response of Angiotensin II by increasing the sensitivity of vascular smooth muscle to vasoconstrictors. Patients receiving these medications should be monitored for potential interactions, and dose adjustments may be necessary to achieve the desired therapeutic effect while minimizing the risk of adverse reactions.