Does "complementary classes" mean "classes (of medicines) that are complementary to main drugs"?

Context:

Because of the aging of the population and rising rates of obesity, hypertension is increasing in prevalence worldwide.http://www.nejm.org/doi/full/10.1056/NEJMoa1402670?query=featured_home#ref1 Approximately 10% of patients with diagnosed hypertension have resistant hypertension, defined as a systolic blood pressure of 140 mm Hg or higher despite adherence to at least three maximally tolerated doses of antihypertensive medications from complementary classes, including a diuretic at an appropriate dose. Patients with resistant hypertension who are receiving appropriate medical therapy have high rates of cardiovascular complications, with few treatment options.