Azilsartan, known by its brand name Edarbi, is a prescription medication used to manage high blood pressure. It belongs to a class of drugs recognized as angiotensin II receptor blockers (ARBs). This medication is available in tablet form, typically in dosages of 40 mg or 80 mg. It relaxes blood vessels, helping to lower blood pressure.
Medical Uses of Azilsartan
Azilsartan is prescribed primarily for the treatment of hypertension in adults. Hypertension is a condition where blood pressure in the arteries remains elevated, often without noticeable symptoms. Managing it is important for long-term health.
Uncontrolled hypertension can lead to serious health complications over time, including an increased risk of stroke, heart attack, heart failure, and kidney disease. By lowering blood pressure, azilsartan reduces the workload on the heart and arteries, decreasing the risk of these severe outcomes. Azilsartan can be used as a standalone therapy or in combination with other antihypertensive agents to achieve desired blood pressure control.
Mechanism of Action
Azilsartan functions by targeting the body’s renin-angiotensin-aldosterone system (RAAS), a hormonal pathway that regulates blood pressure and fluid balance. It blocks angiotensin II type 1 (AT1) receptors.
Angiotensin II is a naturally occurring peptide hormone that causes blood vessels to constrict, leading to increased blood pressure. By preventing angiotensin II from binding to its AT1 receptors, azilsartan inhibits this constricting effect, allowing blood vessels to relax and widen. This vasodilation reduces peripheral resistance, which in turn lowers blood pressure. Furthermore, by blocking these receptors, azilsartan also reduces the secretion of aldosterone, a hormone that promotes sodium and water retention, thereby further contributing to blood pressure reduction.
Common Side Effects and Adverse Reactions
Common side effects include dizziness, fatigue, nausea, and diarrhea. These often appear when treatment begins or dosage is adjusted, typically subsiding as the body adapts. Muscle spasms, skin rash, and itching have also been reported.
More serious, though less common, adverse reactions include:
- Signs of an allergic reaction, such as hives, difficulty breathing, or swelling of the face, lips, tongue, or throat.
- Symptoms of high potassium levels in the blood (hyperkalemia), which can manifest as muscle weakness or an irregular heartbeat.
- Symptoms of kidney injury, such as a decrease in urine output or swelling in the ankles, hands, or feet.
- Excessively low blood pressure (hypotension), which can cause severe dizziness or fainting.
Important Precautions and Drug Interactions
Azilsartan carries a black box warning for use during pregnancy. If pregnancy is detected, azilsartan should be discontinued as soon as possible. Drugs that affect the renin-angiotensin system can cause injury or death to a developing fetus, particularly during the second and third trimesters of pregnancy.
Patients with certain pre-existing conditions require careful consideration before taking azilsartan. Individuals with kidney disease, liver disease, or those who are dehydrated should inform their healthcare provider. Dehydration, often resulting from severe vomiting, diarrhea, or excessive sweating, can lead to dangerously low blood pressure. Volume or salt depletion should be corrected before starting azilsartan therapy.
Azilsartan can interact with several other medications and supplements. Co-administration with nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen or naproxen can potentially worsen kidney function, especially in elderly, dehydrated, or renally compromised patients. Combining azilsartan with lithium can increase lithium levels in the blood, potentially leading to toxicity. Caution is also advised when using azilsartan with other blood pressure medications, especially those that also affect the renin-angiotensin system, such as ACE inhibitors (e.g., lisinopril, ramipril) or aliskiren, due to an increased risk of hypotension, hyperkalemia, and kidney impairment. Potassium supplements or salt substitutes containing potassium should generally be avoided unless specifically advised by a doctor, as azilsartan can increase blood potassium levels.