Clozapine and Oral Contraceptives-Implications Beyond Pharmacokinetics: A Case Report

The potential influence of estrogen-containing oral contraception on clozapine metabolism in a patient with known pharmacogenomic status

Clozapine is primarily metabolized via cytochrome P450(CYP)1A2 and to a lesser extent CYP3A4, CYP2C19, and CYP2D6. Metabolic inhibitors of clozapine, such as fluvoxamine and ciprofloxacin, are important to recognize to avoid adverse drug events. Estrogen-containing oral contraceptives (eOCPs) are weaker CYP1A2 and CYP2C19 inhibitors but are associated with a 2-fold increase of clozapine concentrations. The potential for phenoconversion due to a CYP genetic polymorphism can add additional complexities when considering drug interactions. A case report is presented of a suspected interaction between newly initiated clozapine and a prescribed eOCP for which the patient's pharmacogenomic status was known. A 17-year-old, nonsmoking, White female with a history of schizophrenia was initiated on clozapine 12.5 mg at bedtime with a plan to increase by 25 mg every 4 days in the outpatient setting. The patient was a known rapid CYP1A2 metabolizer without identified sources of CYP1A2 induction and a CYP2C19 rapid metabolizer. Based on pharmacogenomic testing, there was no suspicion for significant gene-drug interactions. Yet, as the patient was prescribed an eOCP, a clozapine concentration was obtained after reaching 150 mg at bedtime. This steady-state clozapine concentration was found to be 560 ng/mL, correlating with worsening sedation and constipation. Given ongoing side effects, clozapine was lowered to 100 mg at bedtime; however, ongoing intolerance ultimately led to clozapine discontinuation. This case highlights the potential interaction between clozapine and eOCP in a CYP1A2 and CYP2C19 rapid metabolizer, leading to clozapine intolerance and discontinuation. The concomitant use of clozapine and eOCPs should be undertaken judiciously.

Reproductive Health Among Those with Schizophrenia Spectrum Disorders: An Overview of Considerations Related to the Premenopausal Period, Pregnancy and Postpartum, and the Menopausal Transition, with a Focus on Recent Findings

PURPOSE OF REVIEW

Schizophrenia spectrum disorders (SSD) impact many aspects of reproductive health for women and non-binary and transgender individuals assigned female at birth. In this narrative review, we highlight considerations and recent research related to (1) the premenopausal period, (2) pregnancy and postpartum, and (3) the menopausal transition.

RECENT FINDINGS

Most recent research has focused on pregnancy and the postpartum period, and specifically on elucidating perinatal risk factors, adverse obstetrical and neonatal outcomes (and modifiable contributors such as smoking), long-term child health, and psychotropic medications (with reassuring results related antipsychotic-associated gestational diabetes mellitus and neurodevelopmental outcomes). Much less recent focus has been on menstruation and menopause, although some research has highlighted the relative worsening of illness peri-menstrually and peri-menopausally. Despite the many important reproductive considerations for those with SSD, many aspects including menstruation and menopause have received very little attention. Further research is needed on how to best support women, non-binary, and transgender people assigned female at birth with SSD throughout the lifespan.