Losartan 1 A Pharma (Losartan Potassium)

Losartan is an angiotensin II receptor blocker used to treat conditions related to the renin‑angiotensin system.

• Hypertension: lowers blood pressure and reduces cardiovascular risk.
• Heart failure: improves symptoms and decreases hospitalization rates.
• Diabetic nephropathy: slows progression of kidney damage in patients with type 2 diabetes.
• Stroke risk reduction: lowers the chance of recurrent stroke in patients with prior cerebrovascular events.

• Losartan potassium selectively antagonizes angiotensin II type 1 (AT₁) receptors on vascular smooth‑muscle cells, adrenal cortex and renal tubular cells. By blocking AT₁ activation, it prevents vasoconstriction, aldosterone secretion and sympathetic stimulation, leading to vasodilation, reduced sodium‑water retention and lower systemic vascular resistance. The resulting effect is a sustained decrease in arterial pressure and mitigation of maladaptive cardiac remodeling.

Losartan may cause a range of adverse reactions, which are categorized by frequency and severity.

Common Side Effects

• Dizziness or light‑headedness
• Headache
• Fatigue
• Upper respiratory tract infection
• Diarrhea

Serious or Rare Side Effects

• Hyperkalemia: elevated blood potassium levels
• Angio‑edema: swelling of face, lips, tongue or throat
• Acute kidney injury: sudden decline in renal function

When prescribing Losartan, clinicians should consider several safety considerations.

• Renal function: assess baseline creatinine and eGFR before initiation.
• Electrolytes: monitor serum potassium periodically, especially with concomitant potassium‑sparing agents.
• Volume status: avoid use in patients with severe dehydration or volume depletion.
• Concomitant NSAIDs: use cautiously as they may reduce antihypertensive effect and impair renal function.
• Pregnancy: discontinue if pregnancy is confirmed; drug is contraindicated in the second and third trimesters.
• Store at ambient temperature: keep below 25 °C, protect from moisture and light in the original container.

Losartan can interact with other medicines, altering its efficacy or safety profile.

Major Interactions (Avoid)

• Aliskiren: combined use in diabetic patients is contraindicated due to increased risk of renal impairment, hyperkalemia and hypotension.
• Potassium supplements or potassium‑sparing diuretics: may cause dangerous hyperkalemia.

Moderate Interactions (Monitor Closely)

• NSAIDs (e.g., ibuprofen): may blunt antihypertensive effect and worsen renal function.
• Lithium: concurrent use can increase lithium levels, risking toxicity.
• ACE inhibitors or other ARBs: additive blood pressure lowering and hyperkalemia risk; avoid simultaneous use.