Acute onset of ascites with clozapine-induced hepatitis

Screening the European pharmacovigilance database for reports of clozapine-related DRESS syndrome: 47 novel cases

Clozapine-related drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a rare adverse reaction. We aimed to screen a large pharmacovigilance database to identify clozapine-related DRESS cases, even if otherwise reported and provide a clinical overview. We screened spontaneous reports of clozapine-related DRESS syndrome in EudraVigilance database applying the European Registry on Severe Cutaneous Adverse Drug Reactions (RegiSCAR) criteria and scores to identify probable/definite DRESS syndrome cases. Clinical and demographic characteristics of included cases were provided and associations between RegiSCAR scores, and time to develop/recover DRESS were assessed. In a total of 262,146 adverse drug reactions reports for 75,190 clozapine-treated patients, 596 cases fulfilled RegiSCAR criteria; ultimately, 51 cases were rated as probable/definite DRESS according to RegiSCAR scores, of which 4 were previously published as case reports. The mean age of patients was 41.06 years (43.1% females), with 13 patients (25.5%) receiving reported co-medication with other DRESS culprit drugs. Median time between clozapine initiation and DRESS symptoms was 25 days. Clozapine dose was associated with days to develop symptoms (Spearman's ρ 0.40, p = 0.03). Organ involvement was reported in all cases followed by fever (n = 49; 96.1%) and eosinophilia (n = 47; 92.2%). Treatment involved clozapine discontinuation for 37 patients (72.5%), while 3.9% (n = 2) of cases ended fatally. Clozapine rechallenge was undertaken in 25 patients (49.0%). The screening of the EudraVigilance database revealed 47 novel clozapine-related DRESS cases, and only one was originally reported as DRESS. Clozapine-related DRESS may occur with clozapine monotherapy not only during dose titration, but also during maintenance treatment.

Unravelling cases of clozapine-related Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) in patients reported otherwise: A systematic review

BACKGROUND

The drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a drug-induced hypersensitivity reaction.

AIMS

Aim was to review reports of clozapine-related reactions fulfilling the registry of severe cutaneous adverse reaction (RegiSCAR) criteria for DRESS syndrome reported as such or otherwise, to provide a descriptive overview of demographic patterns, clinical manifestations, and DRESS course and investigate associations between demographic, DRESS parameters, and clinical outcomes.

METHODS

This review was conducted following preferred reporting items for systematic reviews and meta-analyses guidelines and registered with PROSPERO (registration number CRD42020156385). We searched PubMed/Embase/PsychInfo/Cochrane for reports of clozapine-related reactions meeting RegiSCAR criteria. Associations between RegiSCAR scores and time-to-recovery with demographic/clinical variables were assessed. Demographic/clinical characteristics of patients with versus without reported DRESS were compared using non-parametrical tests.

RESULTS

We identified 26 reports of 27 patients meeting RegiSCAR criteria. Males (n = 19, 70.4%) and patients with schizophrenia (n = 18, 66.7%) were mainly affected. Twelve patients (44.4%) received clozapine-monotherapy. DRESS symptoms manifested within a month after clozapine initiation (n = 24, 88.9%). Lungs and liver were the most common organs involved (n = 12, 44.4%; n = 11, 40.7%), with a mean time to recovery of 33.75 days. Clozapine rechallenge led to DRESS recurrence in four patients. Death rate was 7.4%. No associations were detected between RegiSCAR criteria or days to recovery with any demographic/clinical variables. No differences between patients with versus without reported DRESS were detected.

CONCLUSIONS

Clozapine-related DRESS may be rare, but also underreported. Clinicians need to be aware of it even in patients under clozapine-monotherapy or without skin rash.

Hepatitis, Interstitial Nephritis, and Pancreatitis in Association With Clozapine Treatment: A Systematic Review of Case Series and Reports

PURPOSE/BACKGROUND

Clozapine is the criterion standard in treatment-resistant schizophrenia. We sought to review data on several inflammatory effects associated with clozapine, specifically interstitial nephritis, hepatitis, and pancreatitis.

METHODS/PROCEDURES

We conducted a systematic review to identify studies, published up until December 2017, describing clozapine-induced hepatitis, nephritis, and pancreatitis. The primary objective was to characterize the clinical characteristics associated with each of the specific inflammatory reactions to clozapine.

FINDINGS/RESULTS

We identified 42 cases of inflammatory reactions associated with clozapine treatment- 20 :cases of clozapine-induced hepatitis, 11 cases of nephritis, and 11 of pancreatitis. The mean (SD) age was 38.8 (11.9) years. The mean (SD) dose of clozapine used was 252.4 (133.7) mg. Time to onset of pancreatitis (17.9 [11.2] days; range 4-35 days) was shorter than that for hepatitis (34.2 [20.1] days; range, 12-90 days) and nephritis (27.9 [27.0]; range, 8-90 days) but was not statistically significant (F = 2.267, P = 0.117). The mean (SD) time to recovery was shorter for cases of pancreatitis (15.7 [18.4] days) compared with cases of hepatitis (25.9 [16.5] days) and nephritis (24.5 [18.9] days). Three cases with hepatitis died. Seven of the cases had a clozapine rechallenge (hepatitis [n = 3], nephritis [n = 1], pancreatitis [n = 3]), with 5 having a recurrence at a mean (SD) onset of 3.5 (2.5) days (range, 1-7 days); 2 hepatitis cases were successfully rechallenged.

IMPLICATIONS/CONCLUSIONS

Clozapine-induced hepatitis, nephritis, and pancreatitis are uncommon adverse events, reflected in the paucity of case studies in the literature. Early recognition of the signs and symptoms of clozapine-associated hepatitis, nephritis, and pancreatitis is important, as when identified, clozapine should be urgently discontinued. Clozapine is associated with evidence of benign inflammatory processes; the extent to which hepatitis, and other inflammatory reactions, may be on a continuum with these more benign and self-limiting reactions is unclear, and this can only be resolved by prospectively following cohorts of clozapine-treated patients.

Hepatotoxicity induced by clozapine: a case report and review of literature

Clozapine is an effective antipsychotic drug but is associated with serious side effects. Most treatment guidelines give no clear recommendations on regular monitoring of liver function tests, even though up to 60% of patients experience elevations in hepatic transaminases, with 15% to 30% experiencing an elevation two to three times greater than normal. Though elevations in liver function tests are often transient and asymptomatic, there are many reported cases of clozapine-induced hepatotoxicity, with damage to the liver, involvement of multiple organs, and even fulminant liver failure arising with moderate clozapine doses. This case report describes a Chinese woman who developed hepatotoxicity on a low dose of clozapine, and reviews the relevant literature.

Clozapine-induced fatal fulminant hepatic failure: a case report

Fulminant hepatic failure (FHF) refers to the rapid development of severe acute liver injury with impaired synthetic function and encephalopathy in a person who previously had a normal liver or had wellcompensated liver disease. The potential causes of FHF are numerous, but viral or toxin-induced hepatitis are the most common. Clozapineinduced hepatotoxicity has rarely been reported in the literature, occurs via an unknown mechanism and results in liver biochemical abnormalities that are usually of no clinical significance. In approximately 30% to 50% of patients treated with clozapine, there is an asymptomatic rise in serum aminotransaminase levels; however, there are no current guidelines for routine monitoring of liver function tests and liver enzymes during its use. Fatal fulminant hepatitis has only been reported in three patients receiving clozapine. A case of fatal FHF that occurred in a schizophrenic woman who began clozapine therapy shortly before her illness developed is described.

Clozapine-induced hepatotoxicity in rat hepatocytes by gel entrapment and monolayer culture

Clozapine is limitedly used due to its adverse effect including agranulocytosis and hepatotoxicity. However, the mechanism of clozapine toxicity is still not clear. The previous in vitro studies on microsomes proposed a possible mediation of cytochrome P450 (CYP) in producing reactive metabolites. In this paper, clozapine toxicity was, respectively, examined in two cultures of rat hepatocytes. Gel entrapment culture of hepatocytes with higher expression on CYP activities showed higher sensitivity to clozapine treatment than hepatocyte monolayer, indicating the possible involvement of CYP in hepatotoxicity of clozapine. Moreover, in each culture, CYP inhibitors were used to confirm the possible mediation of CYP enzymes. Pretreatment of hepatocytes with CYP 3A inhibitor (ketoconazole), CYP 2E1 inhibitor (diethyldithiocarbamate, DDC) and non-specific inhibitor (cimetidine) significantly reduced the toxicity of clozapine. But the pretreatment with CYP 1A2 inhibitor (fluvoxamine) had no such protective effect indicative of non-function of CYP 1A2 in clozapine toxicity. In addition, glycyrrhizic acid (GA), a scavenger of reactive oxygen species (ROS), also inhibited the adverse response to clozapine, suggesting the positive involvement of oxidant pressure. Thus, it could be concluded that clozapine-induced toxicity was mediated by CYP, particularly CYP 3A and CYP 2E1, and oxidant pressure.