What is a suitable prescription for valsartan (angiotensin II receptor antagonist) in a patient with hypertension, potentially with a history of heart failure, kidney disease, or liver disease, and possibly taking other medications such as diuretics, beta-blockers, or nonsteroidal anti-inflammatory drugs (NSAIDs)?

Valsartan Prescription Example

For hypertension, prescribe valsartan 80-160 mg once daily as the starting dose, titrating to a maximum of 320 mg daily based on blood pressure response, with monitoring for hypotension, hyperkalemia, and renal function within 1-2 weeks of initiation. 1

Standard Prescription Format

Valsartan 80 mg tablet

• Take one tablet by mouth once daily in the morning
• Dispense: #30 tablets
• Refills: 3
• Indication: Hypertension 1

Dosing Algorithm by Indication

Hypertension (Adult)

• Starting dose: 80 mg once daily for most patients, or 160 mg once daily for those requiring greater blood pressure reduction 1
• Dose range: 80-320 mg once daily 1
• Titration: If additional blood pressure reduction needed after 2-4 weeks, increase to 160 mg, then 320 mg maximum, or add a thiazide diuretic (which provides greater effect than dose increases beyond 80 mg) 1
• Target blood pressure: <130/80 mmHg minimum, ideally <120/80 mmHg for high-risk patients 2

Hypertension (Pediatric, Ages 1-16)

• Starting dose: 1 mg/kg once daily (maximum 40 mg total), or 2 mg/kg in selected cases requiring greater reduction 1
• Maximum dose: 4 mg/kg once daily (maximum 160 mg daily) 1
• Formulation: Use oral suspension for children 1-5 years or those unable to swallow tablets 1

Heart Failure

• Starting dose: 40 mg twice daily 1
• Target dose: 160 mg twice daily (320 mg total daily dose) 3
• Titration: Uptitrate to 80 mg twice daily, then 160 mg twice daily, or to highest tolerated dose; adjust no more frequently than every 2 weeks 3, 1
• Concomitant therapy: Consider reducing diuretic dose during uptitration 1

Post-Myocardial Infarction

• Initiation: May start as early as 12 hours post-MI 1
• Starting dose: 20 mg twice daily 1
• Titration: Uptitrate within 7 days to 40 mg twice daily, then to target of 160 mg twice daily as tolerated 1

Critical Monitoring Parameters

Before Initiation

• Baseline blood pressure (confirm diagnosis with home BP monitoring: ≥135/85 mmHg or 24-hour ambulatory BP ≥130/80 mmHg) 2
• Serum creatinine and estimated glomerular filtration rate 3
• Serum potassium 3
• Volume status (ensure patient is not volume-depleted before starting) 1

During Titration

• Blood pressure: Check within 2-4 weeks after each dose adjustment 2, 3
• Renal function and potassium: Monitor 1-2 weeks after initiation or dose increases, then every 3-6 months 2, 3
• Symptomatic hypotension: Hold dose if systolic BP <90 mmHg with symptoms; reconsider need for other vasodilators 3
• Hyperkalemia: If K+ >5.0 mmol/L, avoid potassium supplements, potassium-sparing diuretics, and NSAIDs; seek specialist advice 3
• Renal dysfunction: Use caution if creatinine >2.5 mg/dL or eGFR <30 mL/min/1.73 m² 3

Combination Therapy Considerations

When to Add Second Agent

• If blood pressure remains ≥140/90 mmHg after 2-4 weeks on valsartan 160 mg, add a calcium channel blocker (amlodipine 5-10 mg daily) or thiazide diuretic (chlorthalidone 12.5-25 mg or hydrochlorothiazide 25 mg daily) 2, 4
• For Black patients, combination of valsartan plus thiazide diuretic may be more effective than valsartan plus calcium channel blocker 4

Triple Therapy

• If uncontrolled on two agents, add the third drug class to achieve ARB + calcium channel blocker + thiazide diuretic combination 2, 4
• This represents guideline-recommended triple therapy with complementary mechanisms 4

Fourth-Line Agent

• If blood pressure remains uncontrolled on optimized triple therapy, add spironolactone 25-50 mg daily as preferred fourth agent for resistant hypertension 4

Contraindications and Precautions

Absolute Contraindications

• Do not combine with ACE inhibitors: Increases risk of hyperkalemia, acute kidney injury, and hypotension without additional cardiovascular benefit 2, 3
• Avoid triple combination: ARB + ACE inhibitor + mineralocorticoid receptor antagonist significantly increases adverse events 3
• Pregnancy (discontinue immediately if pregnancy detected) 1

Relative Contraindications

• Severe hepatic dysfunction or biliary cirrhosis (maximum dose 80 mg daily if used) 5
• Bilateral renal artery stenosis 2
• Severe volume depletion (correct before initiating) 1

Drug Interactions to Avoid

• NSAIDs: May attenuate antihypertensive effect and cause renal impairment; avoid unless essential 2, 3
• Potassium supplements or potassium-sparing diuretics: Increases hyperkalemia risk when combined with valsartan 3
• "Low-salt" substitutes: Often contain high potassium content; avoid 3

Special Populations

Elderly Patients

• No dose adjustment required based on age alone 5
• Monitor closely for hypotension, especially if systolic BP drops below 90 mmHg 3
• Individualize blood pressure targets based on frailty, but do not withhold appropriate treatment solely based on age 4

Renal Impairment

• No dose adjustment needed for creatinine clearance >10 mL/min 5
• Not recommended for pediatric patients with GFR <30 mL/min/1.73 m² 1
• Monitor renal function closely when initiating or uptitrating 3

Hepatic Impairment

• Maximum dose 80 mg daily in patients with hepatic dysfunction 5
• Not recommended in severe hepatic dysfunction or biliary cirrhosis 5

Common Pitfalls to Avoid

• Underdosing: Many physicians use doses that are too low; less than 25% of patients are titrated to target doses in clinical practice 3
• Premature addition of third agent: Optimize doses of first two agents before adding third drug class 4
• Inadequate monitoring: Failure to check potassium and creatinine 1-2 weeks after initiation or dose changes 3
• Combining with ACE inhibitor: This increases adverse events without benefit and should be avoided 2, 3
• Stopping therapy prematurely: Temporary dose reductions may be necessary, but efforts should be made to return to target doses when possible 3
• Ignoring medication adherence: Non-adherence is the most common cause of apparent treatment resistance; verify adherence before adding medications 4

Lifestyle Modifications (Adjunctive)

• Sodium restriction to <1500 mg/day (or reduction of at least 1000 mg/day) 2
• Dietary potassium intake 3500-5000 mg/day from food sources 2
• Weight loss if overweight (target at least 1 kg reduction) 2
• Aerobic exercise 90-150 minutes/week 2
• Alcohol moderation (≤2 drinks/day for men, ≤1 drink/day for women) 2
• DASH diet rich in fruits, vegetables, whole grains, and low-fat dairy 2