Osmotic-release oral system methylphenidate of little help in ADHD

Treatment with osmotic-release oral system methylphenidate falls short of reducing symptoms of attention-deficit hyperactivity disorder (ADHD) in young adult prisoners, as shown in a study.

The 8-week study randomized 200 male prisoners (mean age 20.7 years, mean body mass index 23.7 kg/m²) who had ADHD to receive either 18 mg over-encapsulated prolonged-release methylphenidate hydrochloride (n=101) or placebo capsules (n=99).

Treatment was administered daily, with intake being supervised. Methylphenidate and placebo were initiated at one capsule per day for 1 week. Afterwards, the number of capsules was increased to a maximum dose of four capsules per day following weekly assessments at weeks 2, 3, and 4.

Upward titration was carried on until all 18 ADHD symptoms were scored as negligible (0 or 1 on the Connors Adult ADHD Rating Scale [CAARS-O] scale), there were unacceptable adverse effects, or participants objected to an increase. The dose at the end of week 5 was maintained for the final 3 weeks of the trial.

By week 5, the methylphenidate and placebo groups were taking an average of 2.99 and 3.41 capsules daily, respectively. The corresponding proportion of prescribed medication taken was 47.2 percent and 58.4 percent. The main reason for low adherence to treatment was the failure of the participants to be present at the pharmacy to take their medications. Nevertheless, the entire dose was taken when received.

Outcome data at week 8 was available for 90 participants in the methylphenidate group and 94 in the placebo group.

Compared with placebo, methylphenidate produced a nonsignificant reduction in the primary endpoint of mean CAARS-O score at week 8 (–0.57 points, 95 percent confidence interval, −2.41 to 3.56). The number of patients who responded to treatment, defined as a 20-percent reduction in CAARS-O score, was 48.3 percent with methylphenidate and 47.9 percent with placebo.

There were no significant between-group differences noted for any of the secondary outcomes (emotional dysregulation, mind wandering, violent attitudes, mental health symptoms, and prison officer and educational staff ratings of behaviour and aggression). The mean final titrated dose was 53.8 mg in the methylphenidate group.

The present data do not support routine treatment with osmotic-release oral system methylphenidate in ADHD.