dextromethorphan and Serotonin-Syndrome

Topics: Aged; Analgesics, Opioid; Antitussive Agents; Dextromethorphan; Female; Humans; Serotonin Agents; Serotonin Syndrome; Tramadol

A 63-year-old woman with a history of long-standing depression, maintained on escitalopram, presented with altered mental status. Patient had recently been prescribed dextromethorphan-promethazine cough syrup 2 weeks prior for an upper respiratory tract infection. On admission, she was lethargic and obtunded and found to have inducible myoclonus on examination. The rest of her physical exam was unremarkable. Pertinent lab and imaging findings showed QTc prolongation on ECG, negative electroencephalogram and CT head findings, essentially normal blood tests and a negative toxicology screen. The patient was admitted to the step down unit for close observation; both escitalopram and the cough syrup were suspended and was supportively managed. Overnight the patient's mental status improved and the serial EcGs showed resolution of the prolonged QTc. Patient was discharged home without further complication.

Topics: Antitussive Agents; Citalopram; Cough; Depression; Dextromethorphan; Drug Interactions; Female; Humans; Middle Aged; Selective Serotonin Reuptake Inhibitors; Serotonin Syndrome

Topics: Administration, Oral; Aged; Antitussive Agents; Cough; Dextromethorphan; Dose-Response Relationship, Drug; Humans; Male; Serotonin Syndrome

To report a case of myoclonus that developed after administration of dextromethorphan.. A 64-year-old man was diagnosed with chronic renal failure due to diabetic nephropathy. The patient started on peritoneal dialysis 6 months before he was hospitalized. Two days before hospitalization, he developed cough and sputum and he visited an outpatient clinic, where dextromethorphan was prescribed. After taking a total of 30 mg of dextromethorphan, the patient developed myoclonus, tremor, agitation, slurred speech, and diaphoresis, which continued after he stopped taking the prescribed medicine. He visited an emergency department and was hospitalized for examination and treatment of myoclonus.. As the patient's dialysis schedule was adequate, these symptoms were likely not due to uremia. The blood concentration of dextromethorphan (2.68 ng/mL) 60 hours after the 30-mg dose was higher than expected, and the blood concentration of dextrorphan, a metabolite, was lower than expected. We suspected that myoclonus was due to dextromethorphan-related symptoms induced by CYP2D6, which primarily metabolizes dextromethorphan. We analyzed the CYP2D6 gene for polymorphisms and identified CYP2D6 (*)1/(*)10. The patient had been taking metoprolol 40 mg/day for 2 years. The blood concentration of metoprolol 6 hours after administration was 13 ng/mL, which suggests that it was metabolized normally. Metoprolol has another metabolic pathway, via CYP2C19, and this may have led to its lack of accumulation. Moreover, metoprolol may have bound to active CYP2D6. Thus, affinity for CYP2D6, protein-binding rate, and lipid solubility may influence these drug interactions. Total scores for the Adverse Drug Reaction (ADR) probability scale and the Drug Interaction Probability Scale (DIPS) were 9 (highly probable) and 3 (possible), respectively.. Myoclonus and other symptoms in this patient may have been caused by a prolonged high concentration of dextromethorphan due to CYP2D6 polymorphisms and drug interactions.

Topics: Adrenergic beta-Antagonists; Antihypertensive Agents; Antitussive Agents; Cough; Cytochrome P-450 CYP2D6; Dextromethorphan; Diagnosis, Differential; Drug Interactions; Genotype; Humans; Hypertension; Kidney Failure, Chronic; Male; Metoprolol; Middle Aged; Myoclonus; Peritoneal Dialysis; Serotonin Syndrome

We report the first case of serotonin syndrome caused by overdose of dextromethorphan in Japan. A 34-year-old woman with schizophrenia received a dextromethorphan (Medicon) for a catarrhal symptom from two individual departments of the university hospital by chance. The daily amount of dextromethorphan was up to 180 mg for several days in addition to other regular antipsychotic drugs including risperidone, amitriptyline and levomepromazine. Finally, she was found in deep comatose state (GCS coma scale: E1V1M1) and the trachea was intubated in the emergency room. After admission to intensive care unit, the consciousness gradually improved; however, she was confused and agitated. The situation was normalized within next 24 hours and she was weaned from the mechanical ventilation next day. Serotonin syndrome demonstrates various signs and might be overlooked in an emergency room. Dextromethorphan is considered as a safe antitussive drug; however, the unexpected interaction should be suspected during chronic medical treatment.

Topics: Adult; Antipsychotic Agents; Antitussive Agents; Dextromethorphan; Drug Interactions; Drug Overdose; Excitatory Amino Acid Antagonists; Female; Humans; Serotonin Syndrome

Topics: Chlorpheniramine; Dextromethorphan; Drug Interactions; Histamine H1 Antagonists; Humans; Selective Serotonin Reuptake Inhibitors; Serotonin Syndrome

The ability of dextromethorphan to potentiate serotonin levels and lead to serotonin syndrome is well known but few case reports are published. The lack of published cases suggests therapeutic doses of these drugs are not enough to cause serotonin syndrome. We present two cases of serotonin syndrome associated with supra-therapeutic doses of dextromethorphan and therapeutic levels of a selective serotonin reuptake inhibitors (SSRI).. In case one, serum drug levels from admission revealed a dextromethorphan level of 950 ng/mL (normal < 5), escitalopram of 23 ng/mL (normal < 200), chlorpheniramine of 430 ng/mL (normal < 20) and undetectable levels of aripiprazole and benztropine. In case two, serum drug levels from admission revealed a dextromethorphan level of 2820 ng/mL, sertraline of 12.5 ng/mL (normal < 200), and caffeine of 1.4 microg/mL (normal < or = 9 microg/mL).. To our knowledge, these are the first cases to use serum levels of dextromethorphan and a SSRI to confirm dextromethorphan-induced serotonin syndrome.. Our cases suggest supra-therapeutic dextromethorphan doses with a therapeutic amount of a SSRI are required for serotonin syndrome. More work is needed to answer this question more completely.

Topics: Antitussive Agents; Child; Citalopram; Dextromethorphan; Drug Interactions; Humans; Male; Selective Serotonin Reuptake Inhibitors; Serotonin Syndrome; Sertraline; Treatment Outcome; Young Adult

An 18-year-old male developed a severe serotonin syndrome after recreational ingestion of Coricidin HBP (chlorpheniramine 4 mg and dextromethorphan hydrobromide 30 mg). Propofol infusion rapidly normalized his agitation, neuromuscular hyperactivity, and autonomic instability. Confirmatory analysis demonstrated a dextromethorphan serum concentration of 930 ng/mL. Dextromethorphan can produce serotonin syndrome in the absence of another serotonergic drug.

Topics: Acetaminophen; Adolescent; Algorithms; Chlorpheniramine; Dextromethorphan; Drug Combinations; Drug Overdose; Humans; Hypnotics and Sedatives; Infusions, Intravenous; Male; Phenylpropanolamine; Propofol; Serotonin Syndrome; Substance-Related Disorders

Topics: Adolescent; Amphetamine-Related Disorders; Antidepressive Agents; Antitussive Agents; Anxiety Disorders; Child; Dextromethorphan; Diagnosis, Differential; Drug Interactions; Female; Fluvoxamine; Hallucinogens; Humans; Male; N-Methyl-3,4-methylenedioxyamphetamine; Obsessive-Compulsive Disorder; Seizures; Selective Serotonin Reuptake Inhibitors; Serotonin Agents; Serotonin Syndrome; Sertraline