Olmesartan Medoxomilo + Hidroclorotiazida Ratiopharm (Olmesartan Medoxomil, Hydrochlorothiazide)

• Olmesartan/HCTZ is used to manage hypertension by targeting the renin‑angiotensin system and promoting diuresis.
• Essential hypertension: reduces elevated systolic and diastolic blood pressure.
• Controlled hypertension: helps maintain target blood pressure levels.
• Hypertension with fluid retention: combines vasodilation and diuretic action to improve blood pressure control.

• Olmesartan medoxomil selectively blocks angiotensin II type 1 (AT1) receptors, preventing vasoconstriction and aldosterone release, which lowers systemic vascular resistance. Hydrochlorothiazide acts on the distal convoluted tubule to inhibit Na⁺/Cl⁻ reabsorption, increasing urinary sodium and water excretion, thereby reducing plasma volume. The combined effect produces additive blood‑pressure reduction through decreased vascular tone and reduced fluid overload.

The combination may cause a range of adverse reactions, varying from mild to severe.

Common Side Effects

• Dizziness: light‑headed feeling, especially after standing.
• Headache: mild to moderate pain.
• Increased urination: more frequent bathroom visits.
• Electrolyte imbalance (low potassium): mild muscle cramps.
• Fatigue: general tiredness.

Serious or Rare Side Effects

• Severe hypotension: marked drop in blood pressure causing fainting.
• Acute kidney injury: sudden loss of renal function.
• Hyperkalaemia: dangerously high potassium levels.
• Allergic reaction: rash, swelling, or difficulty breathing.
• Pancreatitis: severe abdominal pain.

Before prescribing, clinicians should consider several safety measures.

• Monitor blood pressure: ensure adequate control and avoid excessive lowering.
• Assess renal function: check serum creatinine and eGFR regularly.
• Check electrolytes: especially potassium and sodium levels.
• Avoid use in severe hepatic impairment: limited metabolism may increase exposure.
• Use caution during pregnancy: potential fetal risk, evaluate benefit‑risk.
• Store at room temperature: keep in original container, protect from moisture.

Olmesartan/HCTZ can affect or be affected by other medicines, requiring attention to potential interactions.

Major Interactions (Avoid)

• Aliskiren in diabetic patients: increased risk of renal dysfunction.
• Potassium‑sparing diuretics (e.g., spironolactone): risk of hyperkalaemia.
• ACE inhibitors or other ARBs: additive renal impairment.
• NSAIDs (e.g., ibuprofen): may blunt antihypertensive effect.
• Lithium: increased lithium toxicity.

Moderate Interactions (Monitor Closely)

• Other thiazide diuretics: additive hypotension.
• Beta‑blockers: enhanced blood‑pressure lowering.
• CYP450 inhibitors (e.g., ketoconazole): may raise olmesartan levels.
• Antacids containing aluminium or magnesium: reduce absorption.
• Warfarin: monitor INR for possible changes.