Olmesartan (Benicar, Olmetec) is an angiotensin receptor blocker (ARB) prescribed for high blood pressure (hypertension). Understanding its long-term side effects is important.
Understanding Olmesartan’s Action
Olmesartan targets the body’s renin-angiotensin-aldosterone system (RAAS), which regulates blood pressure. As an ARB, it prevents angiotensin II from binding to blood vessel receptors.
By blocking these receptors, olmesartan causes blood vessels to relax and widen (vasodilation), lowering blood pressure. It also helps kidneys excrete more salt and water, further reducing blood pressure and easing the heart’s workload.
Documented Long-Term Effects
Sprue-like enteropathy, a rare but serious condition affecting the small intestine, is a significant long-term side effect. It can cause severe, chronic diarrhea, substantial weight loss, and nutrient malabsorption. Symptoms may appear months to years after starting therapy, sometimes requiring hospitalization. Characterized by villous atrophy, symptoms typically resolve upon olmesartan discontinuation, with intestinal healing following.
Olmesartan, like other ARBs, can influence kidney function. While often kidney-protective, it can sometimes lead to decline, especially in individuals with pre-existing kidney disease, heart failure, or those taking NSAIDs. Regular monitoring is important. Small, expected creatinine fluctuations don’t always indicate acute kidney injury, but significant changes warrant medical evaluation.
Hyperkalemia (elevated blood potassium) is another potential long-term effect. ARBs can increase potassium, especially in patients with kidney impairment or those using potassium-sparing diuretics or supplements. High potassium can be dangerous, potentially leading to irregular heart rhythms.
Persistent dizziness or fatigue can be long-term side effects, often stemming from the medication’s blood pressure-lowering effect, which can lead to hypotension. If these symptoms endure, they can affect quality of life. Other less common issues include musculoskeletal pain (e.g., back pain) and a chronic cough, though cough is less frequent than with ACE inhibitors.
Monitoring and Managing Side Effects
Healthcare providers monitor patients on long-term olmesartan therapy to detect and manage potential side effects. Regular blood tests are standard, particularly to assess kidney function (serum creatinine, BUN) and electrolyte levels (especially potassium).
Consistent blood pressure checks ensure effective hypertension control without excessive drops. If side effects arise, providers may adjust dosage, switch medication, or implement specific interventions. Many side effects, including sprue-like enteropathy, often improve or resolve once the medication is discontinued.
When to Consult Your Doctor
If taking olmesartan, contact your healthcare provider for certain symptoms. Seek medical attention for severe or persistent diarrhea, especially with unexplained weight loss, as these could indicate sprue-like enteropathy.
Signs of kidney problems (decreased urination, swelling in ankles/legs, unusual fatigue) warrant prompt medical consultation. Symptoms like muscle weakness, numbness, tingling, or irregular heartbeat could signal elevated potassium, requiring immediate evaluation.
Persistent dizziness or fatigue should also be discussed. Never stop taking olmesartan or any prescribed medication without first consulting your doctor.