Adult: For the treatment of NYHA class II-IV cases in patients who cannot tolerate ACE inhibitors: Initially, 40 mg bid, may be increased at intervals of at least 2 weeks up to 160 mg bid according to the patient's tolerability.
Oral Post-myocardial infarction
Adult: For the reduction of CV mortality in clinically stable patients with left ventricular dysfunction or failure after a recent MI: Therapy may be initiated as early as 12 hours following MI. Initially, 20 mg bid, may be doubled at intervals over the next few weeks up to Max of 160 mg bid according to the patient's tolerability.
Oral Hypertension
Adult: Initially, 80 mg once daily, may be increased to 160 mg once daily according to clinical response. Max: 320 mg once daily. Child: ≥6 years As tab: 18-<35 kg: Initially, 40 mg once daily, may be increased up to a Max of 80 mg once daily if needed; ≥35 kg: Initially, 80 mg once daily. Max: 35-<80 kg: 160 mg daily; ≥80 kg: 320 mg daily. As oral solution: <35 kg: Initially, 20 mg once daily. Max: 40 mg once daily; ≥35 kg: Initially, 40 mg once daily. Max: 80 mg once daily. Doses should be adjusted according to clinical response and tolerability. If switching from tab to the oral solution is clinically essential, the dose should be halved; if switching from oral solution to tab, initially the same dose in mg must be used then titrated further based on blood pressure response. Dosage recommendations may vary among individual products or between countries (refer to specific product or local guidelines).
Hepatic Impairment
Mild to moderate: Max: 80 mg daily. Severe: Contraindicated.
Administration
May be taken with or without food.
Contraindications
Biliary cirrhosis, cholestasis. Severe hepatic impairment. Pregnancy. Concomitant use with aliskiren in patients with diabetes mellitus or renal impairment (GFR <60 mL/min/1.73 m2).
Special Precautions
Patient with aortic or mitral stenosis, hypertrophic obstructive cardiomyopathy, post-MI, heart failure; bilateral or unilateral renal artery stenosis, volume and/or Na depletion; ascites due to cirrhosis or refractory ascites, primary hyperaldosteronism; history of angioedema. Patients undergoing surgery. Black patients. The oral solution of valsartan has higher bioavailability and peak plasma concentration than the tab/cap preparation; therefore, tab/cap and oral solution are not bioequivalent on a mg:mg basis. Renal and mild to moderate hepatic impairment. Children. Lactation.
Adverse Reactions
Significant: Acute kidney injury, increased serum creatinine, hyperkalaemia, hypotension, angioedema. Blood and lymphatic system disorders: Neutropenia, thrombocytopenia. Ear and labyrinth disorders: Vertigo. Gastrointestinal disorders: Nausea, abdominal pain, diarrhoea. General disorders and administration site conditions: Fatigue, asthenia. Immune system disorders: Hypersensitivity including serum sickness. Investigations: Increased liver enzymes, increased BUN, decreased Hb and haematocrit. Metabolism and nutrition disorders: Hyponatraemia. Musculoskeletal and connective tissue disorders: Back pain, myalgia, arthralgia. Nervous system disorders: Dizziness, headache, orthostatic dizziness. Respiratory, thoracic and mediastinal disorders: Cough. Skin and subcutaneous tissue disorders: Rash, pruritus, dermatitis bullous. Vascular disorders: Syncope, orthostatic hypotension, vasculitis.
This drug may cause dizziness or weariness, if affected, do not drive or operate machinery.
Monitoring Parameters
Monitor blood pressure, electrolytes (e.g. serum K levels), and renal function regularly during therapy. Assess for signs of angioedema.
Overdosage
Symptoms: Marked hypotension that may result in a depressed level of consciousness, circulatory collapse and/or shock; tachycardia or bradycardia. Management: Symptomatic and supportive treatment. Induce vomiting for recent ingestion. If hypotension occurs, place the patient in a supine position, then administer normal saline IV infusion to facilitate blood volume correction as needed.
Drug Interactions
Increased serum K levels with K-sparing diuretics (e.g. spironolactone, triamterene, amiloride), K supplements, K-containing salt substitutes, or other agents that may elevate serum K levels (e.g. heparin). May increase serum lithium concentration and toxicity. May reduce the antihypertensive effect and increase the risk of worsening renal function with NSAIDs including aspirin and selective COX-2 inhibitors. Systemic exposure may be increased with inhibitors of OATP1B1 (e.g. rifampicin, ciclosporin) and multidrug resistance protein 2 (MRP2) such as ritonavir. Potentially Fatal: Increased risk of hypotension, hyperkalaemia and reduced renal function (including acute renal failure) with aliskiren and ACE inhibitors.
Food Interaction
Reduced exposure and peak plasma concentration with food; however, reduced exposure is not accompanied by clinically significant decrease in therapeutic effect.
Lab Interference
May result in false-negative aldosterone/renin ratio (ARR).
Action
Description: Mechanism of Action: Valsartan is an angiotensin II receptor antagonist. It selectively inhibits the binding of angiotensin II to the angiotensin II type 1 (AT1) receptors found within many tissues (e.g. vascular smooth muscle, adrenal gland), thereby blocking the vasoconstricting and aldosterone-secreting effects of angiotensin II. Additionally, this action leads to a more efficient inhibition of the angiotensin II CV effects and fewer adverse effects than ACE inhibitors. Onset: Approx 2 hours. Duration: 24 hours. Pharmacokinetics: Absorption: Rapidly absorbed after oral administration. Reduced exposure and peak plasma concentration with food. Absolute bioavailability: Approx 23% (tab/cap); approx 39% (oral solution). Time to peak plasma concentration: 2-4 hours (tab/cap); 1-2 hours (oral solution). Distribution: Plasma protein binding: 94-97%, mainly to serum albumin. Metabolism: Metabolised minimally in the liver by CYP2C9 into the inactive valeryl 4-hydroxy valsartan metabolite. Excretion: Via faeces (approx 83%) and urine (approx 13%) as unchanged drug. Elimination half-life: Approx 6 hours.
Chemical Structure
Valsartan Source: National Center for Biotechnology Information. PubChem Compound Summary for CID 60846, Valsartan. https://pubchem.ncbi.nlm.nih.gov/compound/Valsartan. Accessed Oct. 25, 2023.
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