Assessment of CYP-Mediated Drug Interactions for Enasidenib Based on a Cocktail Study in Patients with Relapse or Refractory Acute Myeloid Leukemia or Myelodysplastic Syndrome.

As a selective and potent inhibitor targeting the isocitrate dehydrogenase-2 (IDH2) mutant protein, enasidenib obtained approval from the US Food and Drug Administration (FDA) in 2017 for adult patients with acute myeloid leukemia (AML) with an IDH2 mutation. In vitro investigations demonstrated that enasidenib affects various drug metabolic enzymes and transporters. This current investigation aimed to assess enasidenib on the pharmacokinetics (PKs) of CYP substrates, including dextromethorphan (CYP2D6 probe drug), flurbiprofen (CYP2C9 probe drug), midazolam (CYP3A4 probe drug), omeprazole (CYP2C19 probe drug), and pioglitazone (CYP2C8 probe drug), in patients with AML or myelodysplastic syndrome. Results showed that following the co-administration of enasidenib (100 mg, once daily) for 28 days, the PK parameters AUC(0-∞) and Cmax of dextromethorphan increased by 1.37 (90% confidence interval (CI): 0.96, 1.96) and 1.24 (90% CI: 0.94, 1.65)-fold, respectively, compared to dextromethorphan alone. For flurbiprofen, these parameters increased by 1.14 (90%CI: 1.01, 1.29) and 0.97 (90% CI 0.86, 1.08)-fold, respectively, when compared to flurbiprofen alone. Conversely, midazolam exhibited decreases to 0.57 (90% CI 0.34, 0.97) and 0.77 (90% CI 0.39, 1.53)-fold, respectively, in comparison to midazolam alone. The parameters for omeprazole increased by 1.86 (90% CI: 1.33, 2.60) and 1.47 (0.93, 2.31)-fold, respectively, compared to omeprazole alone, while those for pioglitazone decreased to 0.80 (90% CI: 0.62, 1.03) and 0.87 (90% CI: 0.65, 1.16)-fold, respectively, in comparison to pioglitazone alone. These findings provide valuable insights into dose recommendations concerning drugs acting as substrates of CYP2D6, CYP2C9, CYP3A4, CYP2C19, and CYP2C8 when administered concurrently with enasidenib.

Medication Utilization Patterns in Patients with Post-COVID Syndrome (PCS): Implications for Polypharmacy and Drug-Drug Interactions.

BACKGROUND: Post-COVID syndrome (PCS) causes lasting symptoms like fatigue and cognitive issues. PCS treatment is non-specific, focusing on symptom management, potentially increasing the risk of polypharmacy. OBJECTIVES: To describe medication use patterns among patients with Post-COVID Syndrome (PCS) and estimate the prevalence of polypharmacy, potential drug-drug interactions, and anticholinergic/sedative burden. METHODS: A cross-sectional analysis of baseline data from the Quebec Action for Post-COVID cohort, consisting of individuals self-identifying with persistent COVID-19 symptoms beyond 12 weeks. Medications were categorized using Anatomical Therapeutic Classification (ATC) codes. Polypharmacy was defined as using five or more concurrent medications. The Anticholinergic and Sedative Burden Catalog assessed anticholinergic and sedative loads. The Lexi-Interact checker identified potential drug-drug interactions, which were categorized into three severity tiers. RESULTS: Out of 414 respondents, 154 (average age 47.7 years) were prescribed medications related to persistent COVID-19 symptoms. Drugs targeting the nervous system were predominant at 54.5%. The median number of medications was 2, while 11.7% reported polypharmacy. Over half of the participants prescribed medications used at least one anticholinergic or sedative medication, and 25% had the potential risk for clinically significant drug-drug interactions, primarily needing therapy monitoring. CONCLUSIONS: Our study reveals prescription patterns for PCS, underscoring the targeted management of nervous system symptoms. The risks associated with polypharmacy, potential drug-drug interactions, and anticholinergic/sedative burden stress the importance of judicious prescribing. While limitations like recall bias and a regional cohort are present, the findings underscore the imperative need for vigilant PCS symptom management.

Adaptative Strategy of Immunosuppressive Drugs Dosage Adjustments When Combined With Nirmatrelvir/Ritonavir in Solid Organ Transplant Recipients With COVID-19.

Nirmatrelvir/ritonavir is a promising option for preventing severe COVID-19 in solid organ transplant recipients with SARS-CoV-2 infection. However, concerns have arisen regarding potential drug interactions with calcineurin inhibitors (CNI). This two-phase multicentre retrospective study, involving 113 patients on tacrolimus and 13 on cyclosporine A, aimed to assess the feasibility and outcomes of recommendations issued by The French societies of transplantation (SFT) and pharmacology (SFPT) for CNI management in this context. The study first evaluated adherence to recommendations, CNI exposure, and clinical outcomes. Notably, 96.5% of patients on tacrolimus adhered to the recommendations, maintaining stable tacrolimus trough concentrations (C0) during nirmatrelvir/ritonavir treatment. After reintroduction, most patients experienced increased C0, with 42.9% surpassing 15 ng/mL, including three patients exceeding 40 ng/mL. Similar trends were observed in cyclosporine A patients, with no COVID-19-related hospitalizations. Moreover, data from 22 patients were used to refine the reintroduction strategy. Modelling analyses suggested reintroducing tacrolimus at 50% of the initial dose on day 8, and then at 100% from day 9 as the optimal approach. In conclusion, the current strategy effectively maintains consistent tacrolimus exposure during nirmatrelvir/ritonavir treatment, and a stepwise reintroduction of tacrolimus may be better suited to the low CYP3A recovery.

Discovering clinical drug-drug interactions with known pharmacokinetics mechanisms using spontaneous reporting systems and electronic health records.

OBJECTIVE: Although the mechanisms behind pharmacokinetic (PK) drug-drug interactions (DDIs) are well-documented, bridging the gap between this knowledge and clinical evidence of DDIs, especially for serious adverse drug reactions (SADRs), remains challenging. While leveraging the FDA Adverse Event Reporting System (FAERS) database along with disproportionality analysis tends to detect a vast number of DDI signals, this abundance complicates further investigation, such as validation through clinical trials. Our study proposed a framework to efficiently prioritize these signals and assessed their reliability using multi-source Electronic Health Records (EHR) to identify top candidates for further investigation. METHODS: We analyzed FAERS data spanning from January 2004 to March 2023, employing four established disproportionality methods: Proportional Reporting Ratio (PRR), Reporting Odds Ratio (ROR), Multi-item Gamma Poisson Shrinker (MGPS), and Bayesian Confidence Propagating Neural Network (BCPNN). Building upon these models, we developed four ranking models to prioritize DDI-SADR signals and cross-referenced signals with DrugBank. To validate the top-ranked signals, we employed longitudinal EHRs from Vanderbilt University Medical Center and the All of Us research program. The performance of each model was assessed by counting how many of the top-ranked signals were confirmed by EHRs and calculating the average ranking of these confirmed signals. RESULTS: Out of 189 DDI-SADR signals identified by all four disproportionality methods, only two were documented in the DrugBank database. By prioritizing the top 20 signals as determined by each of the four disproportionality methods and our four ranking models, 58 unique DDI-SADR signals were selected for EHR validations. Of these, five signals were confirmed. The ranking model, which integrated the MGPS and BCPNN, demonstrated superior performance by assigning the highest priority to those five EHR-confirmed signals. CONCLUSION: The fusion of disproportionality analysis with ranking models, validated through multi-source EHRs, presents a groundbreaking approach to pharmacovigilance. Our study's confirmation of five significant DDI-SADRs, previously unrecorded in the DrugBank database, highlights the essential role of advanced data analysis techniques in identifying ADRs.

Impaired kidney function: supporting the safe use of medicines for patients.

Due to the increasing incidence of acute kidney injury (AKI) and chronic kidney disease (CKD), nurses in most healthcare settings are likely to care for patients with some degree of impaired kidney function. Impaired kidney function can adversely affect the way the body excretes, absorbs, distributes and metabolises medicines (pharmacokinetics), potentially resulting in a wide range of drug-related complications. This article provides an overview of the effects of impaired kidney function on pharmacokinetics and the importance of accurate drug dose adjustments for patients with related conditions. It also discusses various aspects of medicines use in patients with AKI, the pharmacological management of patients with CKD and the use of immunosuppressive therapy in patients who have had a kidney transplant. The authors consider the role of the nurse in ensuring safe medicines use for patients with impaired kidney function throughout the article.

Effects of Quinidine or Rifampin Co-administration on the Single-Dose Pharmacokinetics and Safety of Rilzabrutinib (PRN1008) in Healthy Participants.

This open-label, phase 1 study was conducted with healthy adult participants to evaluate the potential drug-drug interaction between rilzabrutinib and quinidine (an inhibitor of P-glycoprotein [P-gp] and CYP2D6) or rifampin (an inducer of CYP3A and P-gp). Plasma concentrations of rilzabrutinib were measured after a single oral dose of rilzabrutinib 400 mg administered on day 1 and again, following a wash-out period, after co-administration of rilzabrutinib and quinidine or rifampin. Specifically, quinidine was given at a dose of 300 mg every 8 hours for 5 days from day 7 to day 11 (N = 16) while rifampin was given as 600 mg once daily for 11 days from day 7 to day 17 (N = 16) with rilzabrutinib given in the morning of day 10 (during quinidine dosing) or day 16 (during rifampin dosing). Quinidine had no significant effect on rilzabrutinib pharmacokinetics. Rifampin decreased rilzabrutinib exposure (the geometric mean of Cmax and AUC0-∞ decreased by 80.5% and 79.5%, respectively). Single oral doses of rilzabrutinib, with or without quinidine or rifampin, appeared to be well tolerated. These findings indicate that rilzabrutinib is a substrate for CYP3A but not a substrate for P-gp.

The use of potentially interacting supplement-drug pairs in adults with type 2 diabetes: A large population-based cohort study in the UK Biobank.

AIMS: To examine the patterns of use of potentially interacting supplement-drug pairs in adults with type 2 diabetes (T2D) in real-world settings, and to explore the impact of potentially interacting supplement-drug pairs on downstream outcomes. METHODS: Potentially interacting supplement-drug pairs were identified from four tertiary databases. We categorized the potential pharmacodynamic interactions into different clinical types according to their related outcomes and explored their associations with incident outcomes using Cox models. RESULTS: 26,394 participants with T2D in the UK Biobank were included. Half (48.5 %) were supplement users, of whom 85.0 % were taking potentially interacting supplement-drug pairs. The potential pharmacodynamic interactions were related to various clinical outcomes, including reducing the effects of glucose-lowering drugs (50.7 %), hypotension (49.8 %), bleeding (50.4 %) and hepatotoxicity (34.8 %). Exploratory analyses found that the use of potentially interacting supplement-drug pairs was associated with incident hepatic diseases (hazard ratio = 1.26, 95 % confidence interval 1.10-1.44, P < 0.001). CONCLUSIONS: Real-world data suggests that most adults with T2D who concurrently used supplements and drugs were on potentially interacting supplement-drug combinations, with the potential of causing adverse outcomes such as incident hepatic diseases. Clinicians should communicate with patients and assess the potential risk of supplement-drug interactions in clinical settings.

Severe DRESS with myocarditis secondary to naproxen/esomeprazole.

A man in his 60s presented with a widespread erythematous rash and associated chills, paraesthesia and haematuria. He had recently commenced naproxen/esomeprazole. Blood tests showed hypereosinophilia (0.73×109/L) and moderate acute kidney injury. Histology revealed parakeratosis, mild spongiosis with eosinophils. He developed acute coronary syndrome with rapid atrial fibrillation. Coronary angiogram was non-obstructive. Cardiac MRI (CMR) revealed acute myocarditis secondary to Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS). Naproxen/esomeprazole was discontinued, and he was supported with oral corticosteroids. A repeat CMR 3 months later showed resolution of myocarditis. Naproxen/esomeprazole is not a common offending drug. DRESS is a rare drug-induced hypersensitivity reaction with a mortality rate of 10%. The objective of this case report is to highlight the significant but rare cardiac complications that can ensue from DRESS, which warrant prompt recognition and withdrawal of the causative drug.

An Assessment of Medication Errors Among Pediatric Patients in Three Hospitals in Freetown Sierra Leone: Findings and Implications for a Low-Income Country.

Background: Pediatric patients are prone to medicine-related problems like medication errors (MEs), which can potentially cause harm. Yet, this has not been studied in this population in Sierra Leone. Therefore, this study investigated the prevalence and nature of MEs, including potential drug-drug interactions (pDDIs), in pediatric patients. Methods: The study was conducted in three hospitals among pediatric patients in Freetown and consisted of two phases. Phase one was a cross-sectional retrospective review of prescriptions for completeness and accuracy based on the global accuracy score against standard prescription writing guidelines. Phase two was a point prevalence inpatient chart review of MEs categorized into prescription, administration, and dispensing errors and pDDIs. Data was analyzed using frequency, percentages, median, and interquartile range. Kruskal-Wallis H and Mann-Whitney U-tests were used to compare the prescription accuracy between the hospitals, with p<0.05 considered statistically significant. Results: Three hundred and sixty-six (366) pediatric prescriptions and 132 inpatient charts were reviewed in phases one and two of the study, respectively. In phase one, while no prescription attained the global accuracy score (GAS) gold standard of 100%, 106 (29.0%) achieved the 80-100% mark. The patient 63 (17.2%), treatment 228 (62.3%), and prescriber 33 (9.0%) identifiers achieved an overall GAS range of 80-100%. Although the total GAS was not statistically significant (p=0.065), the date (p=0.041), patient (p=<0.001), treatment (p=0.022), and prescriber (p=<0.001) identifiers were statistically significant across the different hospitals. For phase two, the prevalence of MEs was 74 (56.1%), while that of pDDIs was 54 (40.9%). There was a statistically positive correlation between the occurrence of pDDI and number of medicines prescribed (r=0.211, P=0.015). Conclusion: A Low GAS indicates poor compliance with prescription writing guidelines and high prescription errors. Medication errors were observed at each phase of the medication use cycle, while clinically significant pDDIs were also reported. Thus, there is a need for training on prescription writing guidelines and medication errors.

Predicting drug-drug interactions in breast cancer patients treated with CDK4/6 inhibitors and forward planning.

INTRODUCTION: Cyclin-dependent kinase (CDK) 4/6 inhibitors are cornerstones in the treatment of Hormone Receptor (HR) positive and Human Epidermal Growth factor (HER2) negative metastatic breast cancer. Given their widespread use in the metastatic setting and emerging use in the adjuvant setting, studying drug-drug interactions (DDI) of these medications is of utmost importance. AREAS COVERED: This review provides key background information on the CDK4/6 inhibitors, palbociclib, ribociclib, and abemaciclib. We discuss drug-drug interactions including those with proton pump inhibitors as well as CYP3A substrates, inhibitors, and inducers. We describe the effect of these drugs on membrane transporters and their substrates as well as those drugs that increase risk of CDK4/6 toxicities. Finally, we explore future directions for strategies to minimize drug-drug interactions. EXPERT OPINION: It is crucial to be mindful of medications that may interfere with drug absorption, such as proton pump inhibitors, as well as those that interfere with drug metabolism, such as CYP3A4 inhibitors and inducers. Additionally, special consideration should be given to populations at higher risk for polypharmacy, such as older patients with greater comorbidities. These interactions and patient characteristics should be considered when developing individual treatment plans with CDK4/6 inhibitors.

Medication use among the oldest old in the Faroe Islands-A national cross-sectional study.

Aging is often associated with an increasing number of comorbidities that warrant use of multiple drugs which increases the use of potentially inappropriate medications (PIMs), drug-drug interactions (DDIs) and drug-related problems (DRPs). The aim is to assess the prevalence of polypharmacy, PIMs, DDIs and DRPs among Faroese residents aged ≥90 years. In this population-based cross-sectional study, 494 individuals ≥90 years were invited and 298 (60%) participated. A pharmacist-led medication review was performed based on self-information, electronic patient journal and the Faroese Prescription Registry. The prevalence of polypharmacy was 74% with no sex-difference. Approximately 60% of participants used PIMs, primarily benzodiazepines and proton pump inhibitors, the latter being a frequently implicated medication in DRPs. Opioid use was low compared with other Nordic studies. DRPs were observed for 79% with discrepancies in the medication lists as the most common cause, and DDIs were identified for 47% of participants, mostly moderately clinically relevant DDIs. In conclusion, the medication use among the oldest old Faroese resembled that in other Nordic countries with a high prevalence of polypharmacy and use of PIMs, especially PPIs and benzodiazepines. However, no sex-difference was noted in medication use and the use of opioids was low.

Acute quadruple extremity compartment syndrome due to angio-oedema after polypharmacy overdose including olmesartan medoxomil, telmisartan and vildagliptin.

This case report describes a rare manifestation of acute compartment syndrome (ACS) involving all four extremities, precipitated by angio-oedema in a middle-aged woman who consumed an overdose of multiple medications: nifedipine, azelnidipine, amlodipine besylate, olmesartan medoxomil, telmisartan, esaxerenone and vildagliptin. She presented with haemodynamic instability, necessitating intubation. Despite stabilising haemodynamic parameters within 24 hours, she manifested escalating extremity oedema. At 52 hours after ingestion, mottled skin was observed, along with necrotic alterations in the swollen hands and compartment pressures exceeding 30 mm Hg in all extremities. ACS was diagnosed, leading to fasciotomies. The aetiology is postulated to be drug-induced angio-oedema, possibly intensified by the concurrent overdose of olmesartan medoxomil, telmisartan and vildagliptin, each of which has a risk of angio-oedema even at standard dosages. This scenario is a very rare case caused by drug-induced angio-oedema, which underscores the importance of vigilant monitoring to detect ACS in patients with progressing limb oedema.

Non-tuberculous mycobacterial pulmonary infection presenting in a patient with unilateral pulmonary artery agenesis.

People who have structural or developmental lung disease are more likely to develop non-tuberculous mycobacterial infections. We present the case of a young man in his 30s who had unilateral pulmonary artery agenesis on the right side and presented with a 6-month history of productive cough and fever. His CT scan showed nodular and cavitating lesions on the right side, and sputum analysis confirmed infection with Mycobacterium chimaera He had to undergo modifications in his treatment, including a change from rifampicin to rifabutin due to drug interactions and his amikacin had to be stopped due to signs of vestibular toxicity. Using a multidisciplinary approach, we were able to formulate an appropriate drug regimen for him, and he is now under regular follow-up with infectious diseases and respiratory medicine.

Herb-drug interactions: Quantitative analysis of levofloxacin absorption and transporter expression in the rat intestine following combined treatment with Persicaria capitata (Buch.-Ham. ex D. Don) H. Gross.

Persicaria capitata (Buch.-Ham. ex D. Don) H. Gross, a traditional Chinese medicinal plant, is often used to treat various urologic disorders in China. P. capitata extracts (PCE) have been used in combination with levofloxacin (LVFX) to treat urinary tract infections (UTIs) for a long time. However, little is known about the absorption of LVFX and transporter expression in the intestine after combined treatment with PCE, restricting the development and utilization of PCE. In view of this, a UPLC-MS/MS method was established for the determination of LVFX in intestinal sac fluid samples and in situ intestinal circulation perfusate samples to explore the effect of PCE on the intestinal absorption characteristics of LVFX ex vivo and in vivo. To further evaluate the interaction between LVFX and PCE, western blotting, immunohistochemistry, and RT-qPCR were utilized to determine the expression levels of drug transporters (OATP1A2, P-gp, BCRP, and MRP2) involved in the intestinal absorption of LVFX after combined treatment with PCE. Using the everted intestinal sac model, the absorption rate constant (Ka) and cumulative drug absorption (Q) of LVFX in each intestinal segment were significantly lower in groups treated with PCE than in the control group. Ka at 2 h decreased most in the colon segment (from 0.088 to 0.016 µg/h·cm2), and Q at 2 h decreased most in the duodenum (from 213.29 to 33.92 µg). Using the intestinal circulation perfusion model, the Ka value and percentage absorption rate (A) of LVFX in the small intestine decreased significantly when PCE and LVFX were used in combination. These results showed that PCE had a strong inhibitory effect on the absorption of LVFX in the rat small intestine (ex vivo and in vivo intestinal segments). In addition, PCE increased the protein and mRNA expression levels of efflux transporters (P-gp, BCRP, and MRP2) and decreased the expression of the uptake transporter OATP1A2 significantly. The effects increased as the PCE concentration increased. These findings indicated that PCE changed the absorption characteristics of levofloxacin, possibly by affecting the expression of transporters in the small intestine. In addition to revealing a herb-drug interaction (HDI) between PCE and LVFX, these results provide a basis for further studies of their clinical efficacy and mechanism of action.

Investigation of the drug-drug interaction and incompatibility mechanism between Aconitum carmichaelii Debx and Pinellia ternata (Thunb.) Breit.

ETHNOPHARMACOLOGICAL RELEVANCE: The combination of Aconitum carmichaelii Debx (Chuanwu, CW) and Pinellia ternata (Thunb.) Breit (Banxia, BX) forms an herbal pair within the eighteen incompatible medicaments (EIM), indicating that BX and CW are incompatible. However, the scientific understanding of this incompatibility mechanism, especially the corresponding drug-drug interaction (DDI), remains complex and unclear. AIM OF THE STUDY: This study aims to explain the DDI and potential incompatibility mechanism between CW and BX based on pharmacokinetics and cocktail approach. MATERIALS AND METHODS: Ultraperformance liquid chromatography-tandem mass spectrometry methods were established for pharmacokinetics and cocktail studies. To explore the DDI between BX and CW, in the pharmacokinetics study, 10 compounds were determined in rat plasma after administering CW and BX-CW herbal pair extracts. In the cocktail assay, the pharmacokinetic parameters of five probe substrates were utilized to assess the influence of BX on cytochrome P450 (CYP) isoenzyme (dapsone for CYP3A4, phenacetin for CYP1A2, dextromethorphan for CYP2D6, tolbutamide for CYP2C9, and omeprazole for CYP2C19). Finally, the DDI and incompatibility mechanism of CW and BX were integrated to explain the rationality of EIM theory. RESULTS: BX not only enhances the absorption of aconitine and benzoylaconine but also accelerates the metabolism of mesaconitine, benzoylmesaconine, songorine, and fuziline. Moreover, BX affects the activity of CYP enzymes, which regulate the metabolism of toxic compounds. CONCLUSIONS: BX altered the activity of CYP enzymes, consequently affecting the metabolism of toxic compounds from CW. This incompatibility mechanism may be related to the increased absorption of these toxic compounds in vivo.

Incidence and risk factors for potential drug-drug interactions in outpatients receiving opioid analgesics.

BACKGROUND: Opioids are the most frequently used drugs to treat pain in cancer patients. However opioid analgesics can cause adverse effects and potential drug-drug interaction. RESEARCH DESIGN AND METHODS: This cross-sectional retrospective study analyzed pDDI in 1839 patients with opioid analgesics in a large comprehensive hospital in China from January 1 to 31 December 2022. Three drug interaction databases were used to screen for pDDI including Drugs (U.S.A.), Medscape (U.S.A.), and Drug Assistant of Dingxiangyuan (China). RESULTS: The prevalence of pDDIs among 1839 patients was around 41.27% of 759 patients, and 564 patients (74.31%) with pDDIs were diagnosed with tumor. Further, the total of 275 various pDDIs combinations were identified. The combination of oxycodone with morphine had the most frequent occurrence of 229 times, and its adverse effects mainly related to exacerbate central respiratory depression. While, gender, tumor, number of diagnoses, and the variety of opioid analgesics used were independent risk factors for pDDIs. CONCLUSIONS: Outpatients taking opioid analgesics had a higher incidence of pDDIs. As consequently, optimized monitoring and management of patients taking opioid analgesics is recommended in order to ensure patient medication safety.

Agranulocytosis Associated With Psychiatric Polypharmacy: Lessons Learned From a Clinical Case.

Psychiatric polypharmacy involves the use of two or more psychotropic medications to manage a mental and emotional condition. The prevalence of psychotropic polypharmacy has been increasing since the 1990s and has been attributed to the rise in multiple psychiatric conditions presenting in one patient. However, as the prevalence of polypharmacy increases to maximize therapeutic advantages, so does the adverse effect profile of those drugs used in combination, leading to very life-threatening effects such as agranulocytosis. Thus, we report a case of agranulocytosis secondary to polypharmacy in a patient with a history of multiple complex psychiatric conditions.  The patient is a 20-year-old female with a past medical history of major depressive disorder, borderline personality disorder, post-traumatic stress disorder, anxiety disorder, hypothyroidism, and ulcerative colitis. Her psychiatric conditions were managed with multiple medications including chlorpromazine, and clozapine was recently added a month prior to admission. Upon admission, the patient was hemodynamically stable and febrile, with complaints of generalized body aches and myalgia. Laboratory results showed profound leukopenia with a white blood cell count of 1.0x103/uL and a neutrophil number of 0.02x103/uL. The patient was admitted to the hospital for neutropenic sepsis and was aggressively treated with intravenous antibiotics. Her clozapine and chlorpromazine were discontinued. In this report, we discuss the association between chlorpromazine and clozapine use and agranulocytosis, emphasizing the importance of regular monitoring and heightened awareness for patients on these medications. This case also underscores the necessity for cautious polypharmacy medication management in individuals with complex psychiatric conditions, highlighting the potential life-threatening consequences of polypharmacy in this population.