Leung, Jonathan G

Since the discovery of the first psychoactive medications, their psychiatric and medical uses have overlapped. Designating a medication psychiatric or psychotropic is thus arbitrary, based on its most common usage, but labeling it so obscures the full range of its pharmacologic activity and clinical utility. Psychotropic medications (PMs) are frequently used to treat medical conditions or symptoms in the areas of neurology (e.g., migraine, seizure disorder), dermatology (e.g., itching), gastroenterology, and chronic pain, among many others. It is important for both primary care and specialty physicians to be aware of the potential non-psychiatric indications for the use of common PMs such as antidepressants, antipsychotics, and anxiolytics. This review examines the potential benefits and risks of PMs when used for non-psychiatric indications, highlighting how their pharmacologic effects on neurotransmitters contribute to both therapeutic outcomes and adverse effects. It also provides guiding principles for prescribers, including the importance of adjusting doses based on the specific indication, monitoring for harmful side effects, considering age-related factors, and addressing the risks associated with polypharmacy.

Abstract Introduction Alice in Wonderland Syndrome (AIWS) is an uncommon condition manifesting visual and somatosensory disturbances in which patients may perceive objects, including their own bodies, as larger or smaller than they are. In adults, AIWS typically is associated with migraine and epilepsy but has been reported as an adverse effect of topiramate, which is used to treat both illnesses, making it difficult to ascertain whether illness or medication causes altered perceptions. Reported is a case of topiramate-associated AIWS, which adds to the limited reports published on this unique phenomenon. Case Report A 40-year-old woman admitted to a 3-week pain rehabilitation program to treat chronic migraine reported macrosomatognosia that she retrospectively recalled beginning during titration of topiramate. The symptoms of AIWS resolved after the topiramate was discontinued. An assessment with the Naranjo ADR Probability Scale indicated a possible association between topiramate and macrosomatognosia. Discussion In this patient with migraine, the onset of AIWS coincided with titration of topiramate, providing a clue that its emergence may have been an adverse drug reaction rather than the underlying illness. Consistent with previous reports, AIWS resolved shortly after topiramate was discontinued, lending credence to this conclusion. However, the mechanism of AIWS is unknown and may be multifactorial, leaving the possibility that migraine predisposed the patient to develop AIWS from topiramate. Conclusion The long association of AIWS with migraine and epilepsy makes it possible that cases caused by medications used to treat these illnesses, like topiramate, are underreported. Awareness of the temporal relationships between the course of illness and the timing of drug therapy can help guide the recognition of AIWS as a potential adverse event.

Abstract Purpose/Background Clozapine was approved in the United States (US) using 1989 regulations and knowledge. After 30 years, many sections of the US package insert (PI) are outdated. Methods We comprehensively reviewed the literature to propose PI updates. We present the information in 2 articles. In Part I, we focus on basic pharmacology based on 407 relevant articles. Part II focuses on clinical aspects and pharmacovigilance. Findings/Results Based on more recent expectations of Food and Drug Administration regulations, we reviewed clozapine basic pharmacology including the following: 1) clearance, 2) pharmacokinetics and pharmacodynamics, and 3) monitoring tools. We identified 9 major problems in the basic pharmacological sections of the PI including the following: 1) in vivo studies indicate that clozapine is dependent on CYP1A2 for its metabolism, 2) the minor role of CYP2D6 in clozapine metabolism requires removing the PI recommendation to lower clozapine doses in CYP2D6 poor metabolizers, 3) in nontoxic concentrations CYP3A4 has a minor role in clozapine metabolism and potent CYP3A4 inhibitors lack clinically relevant effects, 4) several drug-drug interactions need to be updated based on recent literature, 5) systemic inflammation may decrease clozapine metabolism and increase the risk of clozapine intoxication, 6) obesity may decrease clozapine metabolism, 7) patients of Asian and Indigenous American ancestry need lower clozapine doses, 8) personalized titration and c-reactive protein monitoring should be considered until prospective studies are available, and 9) the half-life section needs to be modified to acknowledge that single dosing at night is frequent in the US. Implications/Conclusions An improvement in the US clozapine PI may lead to improvement in PIs worldwide.

Abstract Purpose/Background This is the second part of a 2-part article that proposes improving the United States (US) clozapine package insert. Part II focuses on fatal outcomes and the 5 boxed warnings, 4 specifically for clozapine: severe neutropenia, seizure, orthostatic hypotension and myocarditis, and 1 for all antipsychotics (elderly with dementia). Methods US reports to the World Health Organization's global pharmacovigilance database were analyzed from clozapine's introduction to January 15, 2023. Findings/Results The US was the top reporter worldwide for clozapine with 56,003 reports and 9587 associated fatal outcomes. The 4 clozapine boxed warnings were associated with 534 fatal outcomes (218 with severe neutropenia, 131 with seizures, 125 with orthostasis, 36 with myocarditis, 24 with cardiomyopathy, and 0 with mitral valve prolapse). With no boxed warnings, pneumonia was associated with 674 fatal outcomes and increased white blood cell count (a sign of infection) with 596 fatal outcomes. After considering overlaps, pneumonia and increases in white blood cell count explained 900 fatalities, or 9.4% of 9587 fatal outcomes. The Food and Drug Administration continues to focus on severe neutropenia which was associated with only 218 or 2.3% of fatal outcomes, whereas 97.7% of fatal outcomes reported in US clozapine-treated patients had another cause. Implications/Conclusions To help prevent future deaths in clozapine-treated patients, the clozapine package insert should focus on fatal outcomes during infections. Part II offers detailed solutions regarding current boxed warnings and lack of a warning for pneumonia and other infections. The Supplementary Material includes letters of support from 124 non-US clozapine experts from 44 countries/regions who support Parts I and II.

Abstract Purpose/Background Clozapine requires careful monitoring to minimize adverse reactions and optimize response. Because of variable pharmacokinetics and interpatient variability, guidelines recommend therapeutic drug monitoring (TDM), although practical guidance is limited. This study aims to characterize patient factors associated with TDM, rates of TDM use over time, turnaround times of TDM results, and influence of institutional initiatives aimed to improve TDM. Methods/Procedures A retrospective chart review was conducted at a large 2000-bed academic medical center from August 1, 2015, to November 26, 2023. Adult patients who were administered clozapine during medical or psychiatric inpatient hospitalizations were included. Data collected included patient demographics, clozapine TDM ordering, and clozapine TDM turnaround time. Yearly TDM rates were analyzed to evaluate the impact of various institutional clozapine-related initiatives on TDM practices. Results There were 679 encounters involving 334 patients; 62.7 % were men, and 84.4% were White. Younger patients were less likely to have levels drawn (odds ratio 0.98, confidence interval 0.97–0.99), while self-identified Asian patients more likely (odds ratio 7.54, confidence interval 1.60–35.42). TDM rates increased significantly over time for both medical ( P = 0.002) and psychiatric ( P < 0.001) admission types, with turnaround times improving from 66.07 hours in 2016 to 28.65 hours in 2022. Overall, TDM annual rates increased from 46.2% in 2015 to 69.6% in 2023. The time-period before and after an institutional initiative, which improved TDM turnaround time, was associated with improvements of TDM rates (36.2% vs 67.9%, P < 0.001) Conclusions This study highlights an increase in clozapine TDM use during the study period, but use remained suboptimal. Improvement of turnaround time was associated with increased TDM rates.

Abstract Background Clozapine is effective for treatment-resistant schizophrenia and bipolar disorder but is often discontinued due to adverse effects. This study compared early clozapine discontinuation rates and reasons in patients with mood and psychotic disorders. Methods Data from all individuals with mood or psychotic disorders who initiated clozapine for the first time at the inpatient psychiatric unit of Mayo Clinic, Rochester, Minnesota, between 2014 and 2022 were retrospectively analyzed. Early clozapine discontinuation, defined as discontinuation within 90 days of initiation, was the primary outcome. Cox proportional hazards regression was used to assess factors associated with discontinuation. Results Of 83 patients (mood group n = 37, psychosis group n = 46), those in the mood group were older (P = 0.022) and more likely to be nonsmokers (P = 0.034). The overall 90-day clozapine discontinuation rate was 45.7%. Early discontinuation was significantly higher in the mood group than in the psychosis group (hazard ratio = 2.41, 95% confidence interval = 1.26–4.64, P = 0.008). Other factors associated with early discontinuation were female sex (P = 0.033), older age (P = 0.026), and nonsmoking (P = 0.001). In multivariable analysis, smoking status was the only factor significantly inversely associated with early clozapine discontinuation (hazard ratio = 0.47, 95% confidence interval = 0.22–0.99, P = 0.048), while diagnostic group, sex, and age did not show significant associations (all P > 0.05). Discontinuations were primarily due to adverse drug reactions in both groups. Conclusions Nearly half of the patients discontinued clozapine early, with higher rates in the mood group. Studies should further explore potential pharmacodynamic and pharmacokinetic factors associated with discontinuation, including the influence of smoking. Careful monitoring and personalized management of side effects are crucial for optimizing clozapine therapy and improving treatment outcomes.

Abstract 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.

Introduction Clozapine is the only antipsychotic approved for treatment-resistant schizophrenia, but without appropriate monitoring, it can be associated with potentially fatal outcomes. An International Adult Clozapine Titration Guideline categorizes patients into normal or slow metabolizers. Categorization provides clozapine titration schedules and recommends regular c-reactive protein (CRP) and clozapine concentration monitoring to reduce the risk of adverse drug reactions (ADRs). The impact of the guideline on clozapine ADRs has not been evaluated. Methods A retrospective chart review assessed clozapine titrations, laboratory monitoring, ADRs, and discontinuations for clozapine-naive adult inpatients at a single center from January 1, 2013, to June 1, 2022. Each patient’s cumulative weekly clozapine dosage was compared with their guideline recommended dosage to create a percent accordance. Linear logistic regression evaluated the relationship between titration speed and the presence of an ADR, while descriptive statistics analyzed laboratory monitoring. Results Forty-three patients were included, with the majority being White males with schizophrenia. An inverse relationship existed between the last inpatient week clozapine dose percent accordance and the probability of an ADR. Nonobese patients were less likely than obese patients to experience an ADR (odds ratio = 0.17; 95% CI, 0.03-0.99). CRP and clozapine concentration monitoring was suboptimal. Discussion Based on our small retrospective review of primarily White males, more aggressive clozapine titrations did not increase ADRs. Future studies with more diverse samples are needed and should focus on specific ADRs, which may have increased occurrence with rapid titrations. Obese patients were at higher risk of ADRs, correlating with the guideline-recommended slower titrations for these patients.