Which of the following are true regarding stimulant medications for the treatment of ADHD? Select all that apply.
A. Amphetamine stimulants promote the release of and inhibit the reuptake of dopamine and norepinephrine while methylphenidate only blocks the reuptake of norepinephrine and dopamine
B. Common side effects of stimulant medications include decreased appetite, weight loss, tics/abnormal movements, increased HR and BP, insomnia and irritability
C. Ritalin LA has a shorter duration of action compared to Ritalin SR
D. All stimulants must be administered before 6 PM to avoid interference with sleep
E. Stimulant medications are not FDA approved for children under 6 years of age
The correct answers are A and B.
ADHD is a common pediatric disease state and should be considered in any child or adolescent aged 4-18 who presents with academic or behavioral problems and symptoms of inattention, hyperactivity, or impulsivity. Stimulants are the first line pharmacologic treatment in patients with ADHD in addition to behavioral modifications. The two classes of stimulants used in the treatment of ADHD are amphetamines and methylphenidates.
Amphetamines promote the release of and inhibit the reuptake of dopamine and norepinephrine. Methylphenidate however only blocks the reuptake of norepinephrine and dopamine into presynaptic neurons making Answer A correct.
While the mechanisms of action vary slightly between amphetamines and methylphenidate, the side effects are similar between classes. Decreased appetite, weight loss, GI upset, increased heart rate and increased blood pressure, insomnia, irritability, and tics/abnormal movements are commonly seen with these medications, making Answer B correct. Due to these side effects and the significance they can have on a child’s health, a baseline blood pressure, heart rate, and weight should be documented prior to beginning treatment and monitored closely after initiation of therapy or dose changes. Because amphetamines and methylphenidate are Schedule 2 controlled medications, each child started on a stimulant medication should be assessed for risk of abuse prior to prescribing stimulants and monitored for signs of misuse, abuse, or addiction throughout treatment.
Ritalin LA is a long acting formulation of methylphenidate. It comes in a capsule form and has a duration of action of 8-12 hours. Because of this long duration of action, Ritalin LA is dosed once daily. Ritalin SR is a sustained release formulation capsule of methylphenidate with a duration of action of 3-8 hours and is dosed 1-2 times daily, making Answer C incorrect.
Since insomnia and sleep disturbances are common side effects of taking stimulant medications, it is recommended to take the last dose of amphetamine and methylphenidate medications before 6 PM with the exception of Jornay PM. Jornay PM is the only dosage form of methylphenidate that is taken once daily in the evening between 6:30 PM and 9:30 PM, making Answer D incorrect. These capsules contain beads with two film coatings. The outer delayed-release coating delays the initial release of methylphenidate while the inner extended-release coating controls the release of the medication throughout the next day. Because of these two film coatings, the Tmax of Jornay PM is 14 hours after taking the dose.
While ADHD is diagnosed between the ages of 4 and 18 years old, the majority of stimulant medications are FDA approved for patients aged 6 years or older. According the AAP Clinical Practice Guidelines, evidence-based behavioral parent training in behavior management (PTBM) and/or behavioral classroom interventions should be used as first line treatment for preschool-aged children, 4 years old to 6th birthday. Immediate release methylphenidate products such as Methylin and Ritalin are FDA approved in children 3 years and older as first line pharmacologic therapy in patients which no improvement in symptoms are noted after trying evidence-based behavioral treatments or these evidence-based behavioral treatments are not available, making Answer E incorrect.