The clinical program for methylphenidate hydrochloride extended-release capsules (LA) consisted of 6 studies: 2 controlled clinical studies conducted in children with ADHD aged 6 to 12 years and 4 clinical pharmacology studies conducted in healthy adult volunteers. These studies included a total of 256 subjects; 195 children with ADHD and 61 healthy adult volunteers. The subjects received methylphenidate hydrochloride extended-release capsules (LA) in doses of 10 to 40 mg per day. Safety of methylphenidate hydrochloride extended-release capsules (LA) was assessed by evaluating frequency and nature of adverse events, routine laboratory tests, vital signs, and body weight. Adverse events during exposure were obtained primarily by general inquiry and recorded by clinical investigators using terminology of their own choosing. Consequently, it is not possible to provide a meaningful estimate of the proportion of individuals experiencing adverse events without first grouping similar types of events into a smaller number of standardized event categories. In the tables and listings that follow, MedDRA terminology has been used to classify reported adverse events. The stated frequencies of adverse events represent the proportion of individuals who experienced, at least once, a treatment-emergent adverse event of the type listed. An event was considered treatment emergent if it occurred for the first time or worsened while receiving therapy following baseline evaluation. Adverse Events in a Double-Blind, Placebo-Controlled, Clinical Trial with Methylphenidate Hydrochloride Extended-Release Capsules (LA) Treatment-Emergent Adverse Events A placebo-controlled, double-blind, parallel-group study was conducted to evaluate the efficacy and safety of methylphenidate hydrochloride extended-release capsules (LA) in children with ADHD aged 6 to 12 years. All subjects received methylphenidate hydrochloride extended-release capsules (LA) for up to 4 weeks, and had their dose optimally adjusted, prior to entering the double-blind phase of the trial. In the 2-week, double-blind treatment phase of this study, patients received either placebo or methylphenidate hydrochloride extended-release capsules (LA) at their individually-titrated dose (range 10 mg to 40 mg). The prescriber should be aware that these figures cannot be used to predict the incidence of adverse events in the course of usual medical practice where patient characteristics and other factors differ from those which prevailed in the clinical trials. Similarly, the cited frequencies cannot be compared with figures obtained from other clinical investigations involving different treatments, uses, and investigators. The cited figures, however, do provide the prescribing physician with some basis for estimating the relative contribution of drug and non-drug factors to the adverse event incidence rate in the population studied. Adverse events with an incidence >5% during the initial 4-week, single-blind methylphenidate hydrochloride extended-release capsules (LA) titration period of this study were headache, insomnia, upper abdominal pain, appetite decreased, and anorexia. Treatment-emergent adverse events with an incidence >2% among methylphenidate hydrochloride extended-release capsules (LA)-treated subjects, during the 2-week, double-blind phase of the clinical study, were as follows: Preferred term Methylphenidate Hydrochloride Extended-Release Capsules (LA) Placebo N = 65 N = 71 N (%) N (%) Anorexia 2 (3.1) 0 (0.0) Insomnia 2 (3.1) 0 (0.0) Adverse Events Associated with Discontinuation of Treatment In the 2-week, double-blind treatment phase of a placebo-controlled parallel-group study in children with ADHD, only 1 methylphenidate hydrochloride extended-release capsules (LA)-treated subject (1/65, 1.5%) discontinued due to an adverse event (depression). In the single-blind titration period of this study, subjects received methylphenidate hydrochloride extended-release capsules (LA) for up to 4 weeks. During this period a total of 6 subjects (6/161, 3.7%) discontinued due to adverse events. The adverse events leading to discontinuation were anger (in 2 patients), hypomania, anxiety, depressed mood, fatigue, migraine and lethargy. Adverse Events with Other Methylphenidate HCl Dosage Forms Nervousness and insomnia are the most common adverse reactions reported with other methylphenidate products. In children, loss of appetite, abdominal pain, weight loss during prolonged therapy, insomnia, and tachycardia may occur more frequently; however, any of the other adverse reactions listed below may also occur. Other reactions include: Cardiac: angina, arrhythmia, palpitations, pulse increased or decreased, tachycardia Gastrointestinal: abdominal pain, nausea Immune: hypersensitivity reactions including skin rash, urticaria, fever, arthralgia, exfoliative dermatitis, erythema multiforme with histopathological findings of necrotizing vasculitis, and thrombocytopenic purpura. Metabolism/Nutrition: anorexia, weight loss during prolonged therapy Nervous System: dizziness, drowsiness, dyskinesia, headache, rare reports of Tourette’s syndrome, toxic psychosis Vascular: blood pressure increased or decreased; cerebrovascular vasculitis; cerebral occlusions; cerebral hemorrhages and cerebrovascular accidents Although a definite causal relationship has not been established, the following have been reported in patients taking methylphenidate: Blood/Lymphatic: leukopenia and/or anemia Hepatobiliary: abnormal liver function, ranging from transaminase elevation to hepatic coma Musculoskeletal: rhabdomyolysis Psychiatric: transient depressed mood, aggressive behavior, libido changes Skin/Subcutaneous: scalp hair loss Very rare reports of neuroleptic malignant syndrome (NMS) have been received, and, in most of these, patients were concurrently receiving therapies associated with NMS. In a single report, a 10-year-old boy who had been taking methylphenidate for approximately 18 months experienced an NMS-like event within 45 minutes of ingesting his first dose of venlafaxine. It is uncertain whether this case represented a drug-drug interaction, a response to either drug alone, or some other cause.