Guidelines and algorithms for the use of methylphenidate in children with Attention-Deficit/ Hyperactivity Disorder

Update on attention-deficit/hyperactivity disorder

PURPOSE OF REVIEW

Attention-deficit/hyperactivity disorder (ADHD) is present in 3% to 10% of children in the United States. Children with ADHD can have academic impairments, social dysfunction, and poor self-esteem. There is also a higher risk of both cigarette smoking and substance abuse. Given this, the importance of treatment for ADHD needs to be underscored. This article will briefly review the diagnosis, etiology, and treatment of ADHD, with particular focus on nonstimulant medication and alternative treatment modalities.

RECENT FINDINGS

Recent evidence suggests that the overall rate of medication treatment for ADHD has been increasing, with over 2 million children being treated with stimulants in 1997. With this increase, controversy has arisen over the possible association of stimulants with growth suppression. In addition, estimates indicate that as many as 30% of children with ADHD either do not respond to stimulant treatment or cannot tolerate the treatment secondary to side effects. This has lead to the consideration of treatment with both nonstimulant medications as well as alternative therapies, including diet, iron supplementation, herbal medications, and neurofeedback. Considering the various treatment options now available for ADHD, along with the complexity of the condition, clinical practice guidelines are emerging for the treatment of ADHD and will be discussed.

SUMMARY

ADHD continues to be a serious health problem. Adequate treatment is needed to avoid academic impairments, social dysfunction, and poor self-esteem. This treatment includes consideration of stimulant medication, nonstimulant medication, as well as alternative therapies. The child with ADHD is likely better served with a mutimodal treatment plan, including medication, parent/school counseling, and behavioral therapy. Implementing an evidenced based algorithm for the treatment of ADHD may prove to be most effective.

Meta-analysis of the efficacy of methylphenidate for treating adult attention-deficit/hyperactivity disorder

This article reviews the efficacy of methylphenidate (MPH) for adult attention-deficit/hyperactivity disorder (ADHD). A literature search identified double-blind placebo-controlled MPH treatment studies of ADHD adults. Meta-analysis estimated the pooled effect size for MPH treatment and tested for publication bias. Meta-analysis regression assessed the influence of study design features on medication effects. Six trials met criteria and were included in this meta-analysis. These studies included a total of 140 MPH-treated ADHD adults and 113 placebo-treated ADHD adults. The mean effect size of 0.9 was statistically significant and there was no evidence of publication bias. Larger MPH effect sizes were associated with physician ratings of outcome and use of higher doses. When treatment is optimized to high doses, the effect size for MPH in adults was 1.3. We found strong support for the assertion that MPH is efficacious for treating adult ADHD. Because the degree of efficacy of MPH in treating ADHD adults is similar to what has been reported from meta-analyses of the child and adolescent literature, our work provides further assurance to clinicians that the diagnosis of ADHD can be validly applied in adulthood.

The use of a laboratory school protocol to evaluate concepts about efficacy and side effects of new formulations of stimulant medications

Recently, new long-acting formulations of racemic methylphenidate (MPH: Ritalin LA, Metadate CD and Concerta) and amphetamine (AMP: Adderall XR) were developed and are now approved by the Food and Drug Administration (FDA). In addition, dexmethylphenidate (Focalin), the pharmacologically active d-threo enantiomer of MPH, also was approved by the FDA. In the initial phases of development, prototypes of these five new formulations were evaluated using the University of California, Irvine (UCI) Laboratory School Protocol (LSP), in which surrogate measures of efficacy are collected in highly controlled settings rather than clinical measures of effectiveness in the less-controlled, natural environments of home or school. The LSP studies were followed by large effectiveness and safety studies required for gaining FDA approval. These initial efficacy and side effect studies in the LSP provided missing information about the basic pharmacokinetic (PK) and pharmacodynamic (PD) properties of MPH and AMP and produced some new discoveries (i.e., acute tolerance) that were used to help design the final products. The final once-a-day formulations used different drug delivery systems to achieve long-acting efficacy (Ritalin LA, Metadate CD, Concerta, Adderall XR). All four drug delivery systems were based on two processes: first, a bolus delivery (BD) process to achieve rapid onset of efficacy (mg), and second, a controlled delivery (CD) process to achieve rates of delivery (mg/hr) or a delayed bolus (mg) to maintain efficacy. A theoretical approach was used to compare and contrast the new once-a day formulations of MPH by selecting total daily doses (mg/d) that would equate drug delivery by the first process (mg of the initial bolus) and the second process (mg/hr over specified time period). In addition to efficacy, applications of the LSP to measure common side effects related to eating and sleeping were described and discussed.