A Case of Constipation and Gastrointestinal Retention of Lisdexamfetamine Dimesylate Capsules in an 11-Year-Old

Attention deficit hyperactivity disorder (ADHD) has a worldwide prevalence of 5.29% and stimulant medications are considered first-line treatment. Common adverse events with these medications include decreased appetite, increased sleep latency, tics, abdominal pain, and weight loss. Lisdexamfetamine dimesylate (LDX) is a stimulant used for treating ADHD and may lead to gastrointestinal, among other adverse effects. In this report, we present a case of constipation and retention of LDX capsules in the gastrointestinal tract. An 11-year-old male with a diagnosis of ADHD was being treated with once daily LDX 30 mg in our clinic. After about ten weeks of treatment, he was brought to an emergency department due to epigastric pain and constipation. An abdominal X-ray was significant for the presence of approximately 20 capsules in the large intestine. He was admitted to the pediatric gastroenterology service. Following management with two saline enemas, fewer capsules were seen on repeat X-ray. The patient was observed overnight, advised to discontinue LDX and discharged home in a stable condition. LDX may be associated with constipation and retention of intact capsules in the gastrointestinal tract. Further research is warranted to exclude the risk of sympathomimetic toxidrome if intact LDX capsules simultaneously disintegrate in the gastrointestinal tract.