Drug Interactions between atomoxetine and Talwin Nx

MONITOR: This warning does not apply to the naloxone component in non-injectable formulations of naloxone-containing combination medicines. Naloxone injection is an antagonist that will reverse the actions of opiates. This reversal can occur when the opiate drug is being used clinically and when it is being abused. Physically dependent patients may experience withdrawal symptoms. Abrupt postoperative opioid reversal has resulted in hypotension, ventricular tachycardia and fibrillation, pulmonary edema, cardiac arrest, encephalopathy, and death.

MANAGEMENT: Patients receiving naloxone injection should be monitored for changes in vital signs, nausea, vomiting, diarrhea, aches, fever, runny nose, sneezing, nervousness, irritability, shivering, abdominal cramps.

MONITOR: Serotonin syndrome has been reported following the concomitant use of atomoxetine with other serotonergic medicinal products. The use of agents with serotonergic activity (such as selective serotonin reuptake inhibitors (SSRIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), monoamine oxidase inhibitors (MAOIs), tetracyclic antidepressants, tricyclic antidepressants, 5-HT1 receptor agonists (triptans), ergot alkaloids, lithium, St. John's wort, phenylpiperidine opioids, dextromethorphan, and tryptophan, among others) may potentiate the risk of serotonin syndrome, a rare but serious and potentially fatal condition. Symptoms of serotonin syndrome may include mental status changes such as irritability, altered consciousness, confusion, hallucination, and coma; autonomic dysfunction such as tachycardia, hyperthermia, diaphoresis, shivering, blood pressure lability, and mydriasis; neuromuscular abnormalities such as hyperreflexia, myoclonus, tremor, rigidity, and ataxia; and gastrointestinal symptoms such as abdominal cramping, nausea, vomiting, and diarrhea.

MANAGEMENT: Some authorities advise caution and closer monitoring for serotonin syndrome when atomoxetine is coadministered with other serotonergic agents, especially during initiation and dose escalations. Patients should be instructed to promptly notify their healthcare provider if they experience symptoms of serotonin syndrome. If serotonin syndrome is suspected, a dose reduction or discontinuation of therapy should be considered depending on the severity of the symptoms. If serotonin syndrome develops during therapy, all serotonergic agents should be discontinued immediately and supportive care rendered as necessary. Due to variability and occasionally prolonged half-lives of these coadministered agents, consulting individual product labeling for specific guidance is advised.