RESUMO
BACKGROUND: Chloroquine and hydroxychloroquine are among several experimental treatments being investigated in the urgent response to the coronavirus disease-2019. With increased use of these medications, physicians need to become knowledgeable of these drugs' neuropsychiatric side effects and interactions with psychiatric medications. OBJECTIVE: Clarify evidence base regarding the psychiatric side effects and psychiatric drug interactions of chloroquine and hydroxychloroquine. METHODS: A literature review was performed in PubMed from 1950 to 2020 regarding psychiatric topics and targeted pharmacological properties of chloroquine and hydroxychloroquine. RESULTS: First, chloroquine and hydroxychloroquine may mildly inhibit CYP2D6 metabolism of psychiatric medications, and psychiatric medications that interfere with CYP2D6 or CYP3A4 activity could alter chloroquine and hydroxychloroquine levels. Second, they may prolong the QT interval, warranting caution with concomitant prescription of other QT prolonging agents. Finally, neuropsychiatric side effects are very uncommon but possible and include a potentially prolonged phenomenon of "psychosis after chloroquine." Hydroxychloroquine has less information available about its neuropsychiatric side effects than chloroquine, with psychosis literature limited to several case reports. Weak evidence suggests a possible association of hydroxychloroquine exposure and increased suicidal ideation. It is not clear whether patients with psychiatric illness are more vulnerable to neuropsychiatric sequela of these medications; however, overdose of these medications by suicidal patients has high risk of mortality. CONCLUSION: The risk of neuropsychiatric side effects of chloroquine and hydroxychloroquine when used for coronavirus disease-2019 treatment is not known. Best practice may include suicide risk assessment for patients treated with hydroxychloroquine. However, delirium is expected to be a more likely etiology of neuropsychiatric symptoms in critically ill patients treated for coronavirus disease-2019, and adjustment disorder is a much more likely etiology of anxiety and depression symptoms than the side effects of chloroquine or hydroxychloroquine.