Lastan (Losartan Potassium)

• Lastan (losartan) acts on the renin‑angiotensin‑aldosterone system to manage several cardiovascular and renal conditions.
• Hypertension: reduces systolic and diastolic blood pressure, decreasing risk of stroke and myocardial infarction.
• Heart failure: improves symptoms, reduces hospitalisation, and prolongs survival in patients with reduced ejection fraction.
• Diabetic nephropathy: slows progression of kidney damage and lowers proteinuria in patients with type 2 diabetes.
• Stroke risk reduction: lowers incidence of recurrent stroke in high‑risk hypertensive individuals.

• Losartan selectively blocks angiotensin II type 1 (AT1) receptors on vascular smooth muscle and adrenal tissue, preventing angiotensin II‑mediated vasoconstriction and aldosterone release. This results in reduced peripheral resistance, lower blood volume, and ultimately a decrease in arterial pressure while providing renal and cardiac protective effects.

Like all medicines, Losartan may cause unwanted reactions; they are classified by frequency and severity.

Common Side Effects

• Dizziness
• Headache
• Fatigue
• Nasal congestion
• Back pain
• Cough

Serious or Rare Side Effects

• Angioedema
• Hyperkalemia
• Acute renal failure
• Severe hypotension
• Hepatic injury
• Neutropenia

• When prescribing or dispensing Losartan, consider the following precautions to ensure safe use.
• Monitor blood pressure: check regularly to avoid hypotension.
• Assess renal function: evaluate serum creatinine before and during therapy.
• Check serum potassium: avoid hyperkalemia, especially with potassium‑sparing agents.
• Use caution in severe hepatic impairment: dose adjustment may be required.
• Avoid use in pregnancy unless clearly needed: limited data on safety.
• Store at below 25°C: keep in the original pack, protect from moisture.

Losartan can interact with other medicines; some combinations should be avoided while others need careful monitoring.

Major Interactions (Avoid)

• Concomitant use with aliskiren in diabetic patients: increased risk of renal impairment.
• Combination with ACE inhibitors or other ARBs: may cause excessive potassium rise and kidney injury.
• Use with potassium‑sparing diuretics (e.g., spironolactone): risk of hyperkalemia.

Moderate Interactions (Monitor Closely)

• Co‑administration with thiazide diuretics: may enhance hypotensive effect.
• Rifampin therapy: may reduce losartan plasma concentrations.
• Strong CYP2C9 inhibitors (e.g., fluconazole): may increase losartan levels.
• Antacids containing aluminium or magnesium: may decrease absorption if taken simultaneously.