Losartan Potassium

Approved Indications:

• Hypertension:
  Treatment of primary and secondary hypertension in adults and children ≥6 years to lower blood pressure and reduce the risk of cardiovascular events such as stroke and myocardial infarction.
• Diabetic Nephropathy (in Type 2 Diabetes):
  To slow the progression of renal disease and reduce proteinuria in hypertensive patients with type 2 diabetes and evidence of renal impairment.
• Heart Failure (HFrEF):
  Used as an alternative to ACE inhibitors in patients intolerant to ACEIs for treating heart failure with reduced ejection fraction.
• Post-Myocardial Infarction:
  To reduce mortality in clinically stable patients with left ventricular systolic dysfunction post-MI, especially when ACE inhibitors are not tolerated.

Clinically Accepted Off-Label Uses:

• Left Ventricular Hypertrophy (LVH):
  To reduce the risk of stroke in hypertensive patients with LVH.
• Chronic Kidney Disease (non-diabetic):
  To reduce proteinuria and delay disease progression in CKD with significant proteinuria.
• Marfan Syndrome:
  As part of therapy to slow aortic root dilation, often in combination with beta-blockers.

রেজিস্টার্ড চিকিৎসকের নির্দেশনা অনুযায়ী ঔষধ সেবন করুন।

Adults:

• Hypertension:
  Initial: 50 mg once daily
  Maintenance: 25–100 mg daily (as a single dose or in two divided doses)
  Maximum: 100 mg/day
• Diabetic Nephropathy:
  Initial: 50 mg once daily
  Target: 100 mg once daily
• Heart Failure:
  Initial: 25–50 mg once daily
  Maintenance: 50–100 mg/day (divided or single dose)

Pediatrics (6–16 years):

• Initial: 0.7 mg/kg once daily (maximum starting dose: 50 mg/day)
• Adjust based on clinical response (max: 1.4 mg/kg or 100 mg/day)

Elderly:

• No initial dose adjustment required. Monitor renal function and potassium levels closely.

Renal Impairment:

• Mild to moderate: No dose adjustment needed
• Severe (eGFR <30 mL/min): Use with caution
• Avoid in bilateral renal artery stenosis

Hepatic Impairment:

• Mild to moderate: Start with 25 mg once daily
• Severe: Use with caution due to limited data

Treatment Duration: Chronic; continue as long as clinically indicated.

রেজিস্টার্ড চিকিৎসকের নির্দেশনা অনুযায়ী ঔষধ সেবন করুন।

Losartan is an angiotensin II receptor blocker (ARB) that selectively inhibits the binding of angiotensin II to the AT1 receptor in vascular smooth muscle and the adrenal gland. This results in vasodilation, decreased aldosterone secretion, reduced sodium and water retention, and ultimately, reduced blood pressure. Unlike ACE inhibitors, losartan does not affect bradykinin degradation, leading to a lower risk of cough and angioedema. These effects also contribute to its renoprotective and cardioprotective actions.

• Absorption: Rapidly absorbed orally
• Bioavailability: Approximately 33%
• Peak Plasma Concentration: 1 hour (losartan), 3–4 hours (active metabolite)
• Protein Binding: >98%
• Metabolism: Hepatic, mainly via CYP2C9 and CYP3A4, to active metabolite EXP3174
• Half-life:
• Losartan: ~2 hours
• Active metabolite: ~6–9 hours
• Excretion:
• Urine: ~35%
• Feces (via bile): ~60%
• Steady-State: Achieved within 2–3 days

Pregnancy:

• FDA Category D (2nd and 3rd trimester):
  Contraindicated due to fetal toxicity including renal failure, oligohydramnios, skull hypoplasia, and fetal death.
  Discontinue immediately if pregnancy is detected.

Lactation:

• Data on excretion in human milk is limited. Animal studies show drug is present in milk.
• Not recommended during breastfeeding due to potential adverse effects on the infant.

• Primary Class: Antihypertensive
• Subclass: Angiotensin II Receptor Blocker (ARB)
• Generation: First-generation ARB

• Hypersensitivity to losartan or any formulation components
• Pregnancy (particularly after first trimester)
• Co-administration with aliskiren in diabetic patients
• Severe hepatic impairment
• Bilateral renal artery stenosis or renal artery stenosis in a single functioning kidney

• Fetal Toxicity: Discontinue immediately when pregnancy is detected
• Hypotension Risk: Especially in volume-depleted or salt-depleted patients
• Renal Impairment: May cause acute renal failure, especially in patients with pre-existing renal artery stenosis
• Hyperkalemia: Monitor potassium levels closely, especially with concomitant potassium-sparing agents or renal impairment
• Hepatic Dysfunction: Use lower doses and monitor liver enzymes
• Angioedema: Rare but serious; discontinue immediately if it occurs
• Avoid Dual RAS Blockade: Combining with ACE inhibitors or aliskiren increases risks without added benefit

Common Side Effects (≥1%):

• Cardiovascular: Dizziness, hypotension
• Respiratory: Nasal congestion, cough
• Gastrointestinal: Diarrhea, abdominal discomfort
• Musculoskeletal: Leg cramps, back pain
• Neurological: Headache, fatigue
• Renal: Mild increases in serum creatinine

Serious or Rare Side Effects:

• Hyperkalemia
• Acute renal failure
• Hepatitis, elevated liver enzymes
• Angioedema
• Anaphylactic reactions

Onset & Severity:

• Most side effects occur early in therapy and are dose-dependent.
• Renal complications and electrolyte disturbances may appear later and require monitoring.

• Potassium Supplements/Potassium-sparing Diuretics (e.g., spironolactone): Risk of hyperkalemia
• NSAIDs: May reduce antihypertensive efficacy and worsen renal function
• Lithium: Increased lithium levels and potential toxicity
• Rifampin: May reduce losartan efficacy (CYP induction)
• Fluconazole: May increase losartan levels and reduce active metabolite formation
• Diuretics: Potentiate antihypertensive effects; risk of hypotension
• Alcohol: Additive hypotensive effects

• Hypertension Guidelines (ACC/AHA, ESC/ESH):
  Losartan remains a recommended first-line therapy, especially for patients with diabetes, CKD, or heart failure.
• FDA Update on Pregnancy:
  Reiterated contraindication in pregnancy and added warnings for use during lactation.
• KDIGO CKD Guidelines:
  Losartan is strongly recommended in patients with proteinuric CKD (diabetic or non-diabetic) for renal protection.

• Temperature: Store at 20°C to 25°C (68°F to 77°F)
• Permissible range: 15°C to 30°C
• Humidity: Protect from moisture; store in original packaging
• Light Protection: Keep in the original blister or bottle to protect from light
• Handling Instructions:
• Do not use beyond the expiration date
• Keep out of reach of children
• No refrigeration or reconstitution needed