Can a 19‑year‑old patient with hypertension be started on losartan?

Can Losartan Be Started in a 19-Year-Old Patient with Hypertension?

Yes, losartan can be started in a 19-year-old patient with hypertension, as the FDA approves losartan for pediatric patients aged 6 years and older, and current guidelines recommend ACE inhibitors or ARBs as first-line therapy for hypertensive adolescents following reproductive counseling. 12

FDA-Approved Age Range

• Losartan is FDA-approved for the treatment of hypertension in pediatric patients 6 years of age and older to lower blood pressure. 1
• The drug has been studied and shown to be effective in lowering blood pressure across all age groups, including adolescents. 1

Guideline-Based Recommendations for Adolescents

• The American Diabetes Association (ADA) 2021 guidelines explicitly recommend ACE inhibitors or angiotensin receptor blockers as the initial pharmacologic treatment of hypertension in children and adolescents. 2
• For adolescents ≥13 years, hypertension is defined as systolic blood pressure ≥130 mmHg or diastolic blood pressure ≥80 mmHg confirmed on three separate days. 2
• Pharmacologic treatment should be considered as soon as hypertension is confirmed (systolic/diastolic ≥95th percentile or ≥140/90 mmHg in adolescents ≥13 years), in addition to lifestyle modification. 2

Critical Reproductive Counseling Requirement

• Before initiating losartan in any adolescent of reproductive age, reproductive counseling is mandatory due to the potential teratogenic effects of ARBs. 2
• Losartan is absolutely contraindicated in pregnancy due to serious fetal toxicity including renal dysfunction, oligohydramnios, skull hypoplasia, and fetal death. 3
• Female patients must understand the need for reliable contraception and immediate discontinuation if pregnancy occurs. 3

Dosing Strategy for Adolescents

• Start losartan at 50 mg once daily in adolescents, which is the standard initial dose for hypertension. 31
• If blood pressure remains ≥140/90 mmHg (or ≥130/80 mmHg in adolescents ≥13 years) after 2–4 weeks, increase to 100 mg once daily. 3
• The goal of treatment is blood pressure consistently <90th percentile for age, sex, and height or <120/80 mmHg in adolescents ≥13 years. 2

Monitoring Requirements

• Measure blood pressure at each routine visit to confirm control. 2
• Check serum creatinine/eGFR and potassium within 1–2 weeks after initiating losartan or after any dose increase. 3
• Reassess blood pressure every 2–4 weeks during titration, aiming to achieve target within 3 months. 3

Secondary Hypertension Screening

• Comprehensive screening for secondary causes of hypertension is recommended in adults diagnosed before age 40 years, except for obese young adults where obstructive sleep apnea evaluation should be prioritized first. 2
• A 19-year-old with hypertension warrants evaluation for renal disease, renovascular disease, endocrine disorders, and coarctation of the aorta before assuming essential hypertension. 2

Combination Therapy if Needed

• If blood pressure remains uncontrolled on losartan 100 mg daily after 4–8 weeks, add hydrochlorothiazide 12.5–25 mg once daily. 3
• The combination of an ARB plus a thiazide diuretic is a guideline-endorsed first-line regimen for most patients with confirmed hypertension. 2

Safety Considerations Specific to Young Patients

• Losartan is well tolerated in adolescents, with dizziness being the most common drug-related adverse effect (2.4% vs 1.3% placebo). 4
• First-dose hypotension is uncommon with losartan due to its slower onset of action. 5
• The overall withdrawal rate due to adverse experiences with losartan (2.3%) is lower than placebo (3.7%). 4

Common Pitfalls to Avoid

• Do not delay treatment in a 19-year-old with confirmed hypertension; pharmacologic therapy should be initiated promptly alongside lifestyle measures when BP is ≥140/90 mmHg. 2
• Do not skip reproductive counseling in female patients—this is a mandatory step before prescribing any ARB or ACE inhibitor to adolescents. 2
• Do not combine losartan with an ACE inhibitor; dual renin-angiotensin system blockade increases the risk of hyperkalemia, syncope, and acute kidney injury without added benefit. 3
• Do not assume essential hypertension without screening for secondary causes in this age group. 2