Double burden of cancer and bipolar disorder: Implications for mental health care

Table 3 Key psychotropic-oncologic drug interactions and monitoring recommendations

Psychotropic drug/class	Relevant oncologic context	Potential interaction or risk	Monitoring/management recommendation
Lithium	Platinum-based chemotherapy, dehydration from chemotherapy (vomiting, diarrhea)	Reduced renal clearance leading to lithium toxicity	Monitor serum lithium levels, renal function, and electrolytes during treatment cycles
Carbamazepine	Taxanes, vinca alkaloids, etoposide	Cytochrome P450 enzyme system (CYP3A4) induction may reduce plasma levels of chemotherapeutic agents	Consider alternative mood stabilizer or monitor oncologic drug efficacy
Valproate	Hepatically metabolized anticancer drugs	Altered hepatic metabolism and potential hematologic toxicity	Monitor liver function tests and blood counts
Antipsychotics (e.g., quetiapine, haloperidol)	QT-prolonging anticancer agents	Additive QT interval prolongation and arrhythmia risk	Baseline and follow-up electrocardiogram monitoring
Clozapine	Myelosuppressive chemotherapy	Additive risk of neutropenia/agranulocytosis	Frequent blood count monitoring and close psychiatry-oncology coordination
Corticosteroids (oncologic supportive therapy)	Steroid-containing chemotherapy regimens	Risk of steroid-induced mania or mood destabilization	Monitor for insomnia, irritability, and manic symptoms; adjust mood stabilizer if needed