Losartan


Generic Medicine Info
Indications and Dosage
Oral
Hypertension
Adult: 50 mg once daily, may increase to 100 mg once daily according to clinical response. Patient with intravascular volume depletion: Initially, 25 mg once daily.
Child: ≥6 years weighing 20-50 kg: Initially, 0.7 mg/kg once daily, may adjust as necessary up to Max of 50 mg daily; >50 kg: Same as adult dose.

Oral
Diabetic nephropathy in type 2 diabetes mellitus
Adult: Initially, 50 mg once daily, may increase to 100 mg once daily according to clinical response.

Oral
Chronic heart failure
Adult: In patients with reduced LVEF where treatment with ACE-inhibitors is unsuitable or contraindicated: Initially, 12.5 mg once daily, may titrate dose at weekly intervals up to Max of 150 mg once daily according to clinical response and tolerability. Treatment recommendations may vary among individual products and between countries (refer to specific product guidelines).

Oral
Hypertension with left ventricular hypertrophy
Adult: To reduce the risk of stroke: Initially, 50 mg once daily. Hydrochlorothiazide should be added and/or losartan should be increased to 100 mg once daily according to clinical response. Treatment recommendations may vary among individual products and between countries (refer to specific product guidelines).
Hepatic Impairment
Hypertension; Diabetic nephropathy in type 2 diabetes mellitus; Hypertension with left ventricular hypertrophy:
Mild to moderate: Initially, 25 mg once daily. Severe: Contraindicated.

Chronic heart failure:
Mild to moderate: Dose reduction may be required. Severe: Contraindicated.
Administration
May be taken with or without food.
Reconstitution
Oral susp: Instruction for reconstitution may vary among individual products and between countries (refer to specific product guidelines).
Contraindications
Severe hepatic impairment. Pregnancy. Concomitant use with aliskiren-containing products in patients with diabetes mellitus or renal impairment (GFR <60 mL/min/1.73 m2).
Special Precautions
Patient with history of angioedema, volume and/or Na depletion, heart failure, bilateral renal artery stenosis or stenosis of the artery to a solitary kidney, aortic or mitral stenosis, obstructive hypertrophic cardiomyopathy, ischaemic CV and cerebrovascular disease. Patient undergoing surgery. Black patients. Not recommended for use in patients with ascites due to cirrhosis or refractory ascites; primary hyperaldosteronism. Renal impairment and mild to moderate hepatic impairment. Children and elderly. Lactation.
Adverse Reactions
Significant: Renal failure (e.g. acute kidney injury), symptomatic hypotension (in volume- and/or Na-depleted patients), electrolyte imbalance (e.g. hyperkalaemia), angioedema.
Blood and lymphatic system disorders: Anaemia.
Cardiac disorders: Angina pectoris, palpitations.
Ear and labyrinth disorders: Tinnitus, vertigo.
Gastrointestinal disorders: Abdominal pain, nausea, vomiting, diarrhoea.
General disorders and administration site conditions: Oedema, asthenia, fatigue.
Hepatobiliary disorders: Rarely, hepatitis.
Investigations: Increase in serum creatinine or blood urea.
Metabolism and nutrition disorders: Hypoglycaemia.
Musculoskeletal and connective tissue disorders: Back pain, arthralgia, myalgia; rarely, rhabdomyolysis.
Nervous system disorders: Dizziness, headache, migraine, paraesthesia.
Psychiatric disorders: Sleep disorders, depression.
Respiratory, thoracic and mediastinal disorders: Dyspnoea.
Skin and subcutaneous tissue disorders: Urticaria, pruritus, rash.
Vascular disorders: Orthostatic hypotension, syncope.
Patient Counseling Information
This drug may occasionally cause dizziness or drowsiness, if affected, do not drive or operate machinery.
Monitoring Parameters
Monitor blood pressure (at baseline and periodically), renal function, and electrolytes (e.g. serum K). Assess for signs of angioedema.
Overdosage
Symptoms: Hypotension, tachycardia, bradycardia (may occur from parasympathetic [vagal] stimulation). Management: Supportive and symptomatic treatment. Prioritise stabilisation of the CV system. Administer activated charcoal as indicated. Perform close monitoring of vital parameters. Correct vital parameters as necessary.
Drug Interactions
May increase the risk of hypotension with TCAs, antipsychotics, baclofen, and amifostine. Concomitant use with fluconazole may increase the plasma concentration of losartan but decrease the plasma concentration of the active metabolite. Decreased plasma concentration with rifampicin. Increased serum K levels with K-sparing diuretics (e.g. amiloride, spironolactone, triamterene), K supplements, K-containing salt substitutes, or other drugs that may increase serum K (e.g. heparin, trimethoprim-containing products); not recommended for concomitant use. May increase serum lithium concentrations and toxicity. Concomitant use with NSAIDs (e.g. selective COX-2 inhibitors, aspirin, non-selective NSAIDs) may increase the risk of worsening of renal function (including possible acute renal failure) and may decrease the hypotensive effect of losartan.
Potentially Fatal: Increased risk of hypotension, hyperkalaemia, and changes in renal function (including acute renal failure) with ACE-inhibitors or aliskiren.
Action
Description: Losartan is a competitive angiotensin II receptor antagonist. It selectively blocks AT1 receptors found in many tissues (e.g. vascular smooth muscle, adrenal gland), thereby blocking the vasoconstricting and aldosterone-secreting effects of angiotensin II. Additionally, losartan does not affect the response to bradykinin and is less likely to be associated with non-renin-angiotensin effects (e.g. cough, angioedema).
Onset: Approx 6 hours.
Pharmacokinetics:
Absorption: Well absorbed from the gastrointestinal tract. Bioavailability: Approx 33%. Time to peak plasma concentration: 1 hour (losartan); 3-4 hours (active metabolite).
Distribution: Volume of distribution: 34 L. Plasma protein binding: >98%, mainly to albumin.
Metabolism: Metabolised in the liver by CYP2C9 and CYP3A4 isoenzymes into E-3174 (active metabolite; more potent than losartan). Undergoes extensive first-pass metabolism.
Excretion: Via urine (35%; approx 4% as unchanged drug, approx 6% as active metabolite); faeces (approx 60%). Elimination half-life: 2.1 ± 0.7 hours (losartan); 7.4 ± 2.4 hours (active metabolite).
Chemical Structure

Chemical Structure Image
Losartan

Source: National Center for Biotechnology Information. PubChem Compound Summary for CID 3961, Losartan. https://pubchem.ncbi.nlm.nih.gov/compound/Losartan. Accessed May 27, 2022.

Storage
Store between 15-30°C. Protect from light.
MIMS Class
Angiotensin II Antagonists
ATC Classification
C09CA01 - losartan ; Belongs to the class of angiotensin II receptor blockers (ARBs). Used in the treatment of cardiovascular disease.
References
Anon. Losartan Potassium. AHFS Clinical Drug Information [online]. Bethesda, MD. American Society of Health-System Pharmacists, Inc. https://www.ahfscdi.com. Accessed 13/05/2022.

Anon. Losartan. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. https://online.lexi.com. Accessed 07/02/2022.

Buckingham R (ed). Losartan Potassium. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 07/02/2022.

Cozaar (Merck Sharp & Dohme [Malaysia] Sdn. Bhd.). National Pharmaceutical Regulatory Agency - Ministry of Health Malaysia. https://www.npra.gov.my. Accessed 07/02/2022.

Cozaar 100 mg Film-coated Tablets (Merck Sharp & Dohme Limited). MHRA. https://products.mhra.gov.uk. Accessed 07/02/2022.

Cozaar 12.5 mg Film-coated Tablets (Merck Sharp & Dohme Limited). MHRA. https://products.mhra.gov.uk. Accessed 07/02/2022.

Cozaar 2.5 mg/mL Powder and Solvent for Oral Suspension (Merck Sharp and Dohme Limited). MHRA. https://products.mhra.gov.uk. Accessed 07/02/2022.

Cozaar 25 mg Film-coated Tablets (Organon Pharma [UK] Limited). MHRA. https://products.mhra.gov.uk. Accessed 07/02/2022.

Cozaar 50 mg Film-coated Tablets (Merck Sharp & Dohme Limited). MHRA. https://products.mhra.gov.uk. Accessed 07/02/2022.

Cozaar Losartan Potassium Tablet, Film Coated (Merck Sharp & Dohme Corp.). DailyMed. Source: U.S. National Library of Medicine. https://dailymed.nlm.nih.gov/dailymed. Accessed 07/02/2022.

Joint Formulary Committee. Losartan Potassium. British National Formulary [online]. London. BMJ Group and Pharmaceutical Press. https://www.medicinescomplete.com. Accessed 07/02/2022.

Teva Pharma (New Zealand) Limited. Losartan Actavis 12.5 mg, 25 mg, 50 mg, 100 mg Tablets data sheet 03 July 2017. Medsafe. http://www.medsafe.govt.nz. Accessed 07/02/2022.

Disclaimer: This information is independently developed by MIMS based on Losartan from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2022 MIMS. All rights reserved. Powered by MIMS.com
  • Bepsar
  • Covance
  • Losacar
  • Losamark
  • Losar
  • Losart 25
  • Normopress
  • Pellosa 50
  • Prosan
  • RePACE/RePACE H
  • Xavor
Register or sign in to continue
Asia's one-stop resource for medical news, clinical reference and education
Sign up for free
Already a member? Sign in