ARB Dosing and Frequency
Start with the recommended initial doses from the 2017 ACC/AHA guidelines: losartan 50-100 mg once or twice daily, valsartan 80-320 mg once daily, irbesartan 150-300 mg once daily, olmesartan 20-40 mg once daily, telmisartan 20-80 mg once daily, and candesartan 8-32 mg once daily. 1
Standard Initial Dosing by Agent
The guideline-recommended starting doses are:
- Losartan: 50-100 mg once or twice daily 1
- Valsartan: 80-320 mg once daily 1
- Irbesartan: 150 mg once daily (can increase to 300 mg) 2
- Olmesartan: 20-40 mg once daily 1
- Telmisartan: 20-80 mg once daily 1
- Candesartan: 8-32 mg once daily 1
All ARBs are dosed once daily except losartan, which may require twice-daily dosing for sustained 24-hour control 1.
Dose Adjustments for Special Populations
Volume-Depleted Patients
Reduce the initial dose by half in volume-depleted patients or those on aggressive diuretic therapy. Specifically, start irbesartan at 75 mg once daily in these patients 2. This prevents excessive hypotension from the first dose.
Renal Impairment
No dose adjustment is necessary for mild-to-moderate renal impairment unless the patient is also volume-depleted 3. The evidence shows:
- Losartan, irbesartan, and olmesartan can be used at standard doses in mild-to-moderate renal insufficiency (GFR 20-60 mL/min) 4, 5
- For severe renal impairment with olmesartan, consider a lower starting dose with a maximum of 20 mg daily 6
- Patients on hemodialysis tolerated losartan 50-100 mg once daily without dose adjustment 4
The key caveat: monitor potassium closely, as hyperkalemia risk increases with declining renal function 1, 7.
Hepatic Impairment
Start losartan at 25 mg once daily in patients with mild-to-moderate hepatic impairment 3. Plasma concentrations increase 5-fold for losartan and 1.7-fold for its active metabolite in hepatic dysfunction. Losartan has not been studied in severe hepatic impairment and should be avoided 3.
Elderly Patients
No dose adjustment is required based on age alone 3. While elderly patients (≥65 years) show 44% higher peak concentrations and longer half-lives with olmesartan 6, and losartan shows similar patterns 3, these increases are well within the safety margin observed at maximum doses. Clinical trials showed no differences in safety or efficacy between elderly and younger patients 3.
Titration Strategy
When initial monotherapy fails to achieve blood pressure goals, uptitrate to the maximum approved dose before adding a second agent. The dose-response relationship for ARBs is not flat as commonly believed 8. Olmesartan uptitration from 20 mg to 40 mg produces clinically meaningful additional blood pressure reductions and significantly increases goal attainment rates 8.
Critical Safety Warnings
- Never combine an ARB with an ACE inhibitor and/or renin inhibitor—this is potentially harmful 1
- Monitor potassium levels, especially in patients with CKD or those taking potassium supplements or potassium-sparing diuretics 1, 7
- Avoid in pregnancy 1, 7
- Watch for acute renal failure in patients with severe bilateral renal artery stenosis 1, 7
- If a patient has angioedema history with an ACE inhibitor, wait 6 weeks after discontinuation before starting an ARB 1
Comparative Efficacy Notes
While all ARBs effectively lower blood pressure, recent network meta-analyses suggest olmesartan and telmisartan demonstrate superior blood pressure reduction with favorable safety profiles 9. Olmesartan ranked highest for both office blood pressure reduction (91.4% for systolic) and safety (70.8%) 9. However, for long-term cardiovascular outcomes in real-world practice, all seven commonly used ARBs showed similar mortality and MACE rates 10.