Issues in the pharmacologic management of primary hypertension in adolescence.
Hypertension may occur in as many as 12% of adolescents and is usually of primary origin. There is an age-related increase of the blood pressure, making it difficult to define the limits of normal. True hypertension can be defined as blood pressure exceeding 140/90 mmHg regardless of age. Borderline blood pressure is said to exist when the blood pressure is above the 90th percentile for age. Blood pressure can be lowered with a wide variety of drugs, and adolescents are most often prescribed adult doses. There are specific concerns about the drugs' side effects in adolescents, particularly effects on growth and development, cognitive function, and metabolism. Diuretics are not the best first choice for therapy because of their metabolic effects. Cardiac hypertrophy and the morbidity of sustained hypertension are reduced by sympathetic inhibitors. Beta-blockers are the best currently available choice, although newer alpha-blocking agents may have some advantages. Even borderline pressure has been associated with evidence of cardiac hypertrophy, and there is substantial evidence that the adolescents with the highest blood pressures, even if still within normal limits, have the highest likelihood of developing sustained hypertension as adults. Yet there is no data establishing a beneficial effect on long-term risk of early treatment with drugs. For these reasons, nonpharmacologic intervention and close follow up are preferred as treatment for borderline blood pressure.