The percentage of those of Hispanic origin in the United States who were of Mexican background in 2013. Another 9.5 percent were of Puerto Rican background, 3.7 percent Cuban, 3.7 percent Salvadoran, 3.3 percent Dominican and 2.4 percent Guatemalan.
Onset of effects occurs within 30-60 minutes after taking Concerta. After that, duration of action lasts from 8-12 hours. And the average times to reach peak plasma concentrations across all doses of Concerta occur between 6-10 hour s. The average half-life for Concerta in adults is about 3.5 hours.
Concerta (methylphenidate-naÃ¯ve) 1  Trilayer core tablets; extended-release core with immediate release. 2  Initial: 18 mg PO qDay; dosage may be increased by 18 mg/day at weekly intervals.  Do not exceed 54 mg/day in children (6-12 years) and 72 mg/day in adolescents (13-17 years)