Use of medicinal plants by ambulatory patients in Puerto Rico.

The use of medicinal plants by the patients at the outpatient clinics of five health-care centers in Puerto Rico was evaluated. Medication histories were obtained for 802 patients ranging in age from two months to 91 years. The most frequent medical diagnosis was cardiovascular disease (54% of the patients). Respiratory and digestive disorders were the least frequent conditions, identified in only 9% and 6% of the cases, respectively. Medicinal plants were used by 57% of the population. Patients 65 years or older tended to use herbal remedies more often. Seven of the 11 most commonly used plants were used to treat gastrointestinal disorders. Other medicinal uses given were for sedation, sleep disorders, elevated blood pressure, kidney disorders, and respiratory ailments. The most frequently used plant was Citrus aurantium L. (sour orange), which was used as a sedative by 39% of the patients and for gastrointestinal disorders by 17%. Two potentially toxic plants, Solanum americanum and Annona muricata, were among the most commonly used plants. Medicinal plants were used widely by the outpatient population studied. Most herbs were used to treat self-limiting conditions but some were used to treat potentially serious medical problems, such as hypertension.