Acute onset clozapine-induced hyperglycaemia: A case report

Rethinking Clozapine: Lights and Shadows of a Revolutionary Drug

The current literature globally highlights the efficacy of Clozapine in several psychiatric disorders all over the world, with an FDA indication for reducing the risk of repeated suicidal behavior in patients with schizophrenia or schizoaffective disorder. A growing field of research is also stressing a possible broader beneficial effect of Clozapine in promoting neuroprotection and neurotrophism. However, this drug is linked to several life-threatening side effects, such as agranulocytosis, myocarditis and seizures, that limit its use in daily clinical practice. For this work, a search was performed on PubMed using the terms "Clozapine indications", "Clozapine adverse effects", "Clozapine regenerative effects", and "Clozapine neuroplasticity" with the aim of reviewing the scientific literature on Clozapine's treatment indications, adverse effects and potential regenerative role. The results confirmed the efficacy of clozapine in clinical practice, although limited by its adverse effects. It appears crucial to raise awareness among clinicians about the potential benefits of using Clozapine, as well educating medical personnel about its risks and the early identification of possible adverse effects and their management.

Assessment of antipsychotic-induced cytotoxic effects on isolated CD1 mouse pancreatic beta cells

Objectives

The study aims to assess apoptosis, oxidative stress, and inflammation as underlying diabetogenic mechanisms in isolated CD1 mouse beta-pancreatic cells of some prescribed Antipsychotics (APs).

Methods

Three types of APs were tested in different concentrations (0.1, 1, 10, and 100 μM) on adult male CD1 mice. The cytotoxicity of the tested APs was determined using different assays including MTT and Lactate Dehydrogenase (LDH) assays. Oxidative stress was assessed by and measuring Reactive oxygen species (ROS) production, lipid peroxidation, and antioxidant enzyme activities. Moreover, the effect on the inflammatory cascade was also investigated.

Results

The tested APs were cytotoxic to beta cells and showed patterns dependent on both concentration and exposure, with a parallel reduction in glucose-stimulated insulin secretion of the treated cells. The APs also showed induction of oxidative stress in the treated cells by significantly increasing the ROS, lipid peroxidation, and NRf2 gene expression, together with decreased antioxidant enzyme activities. Moreover, APs showed significant increases in cytokines levels to their estimated IC50 levels. The activities of caspases 3, 8, and 9 were also significantly increased in all treated samples at their IC50s and at 10 μM concentrations of all tested APs. However, the glutathione and inhibitors of caspase-3, IL-6, and TNF-α significantly improved GSIS and the viability of the AP-treated cells.

Conclusion

The results suggest a significant role for apoptosis, oxidative stress, and inflammation, in the diabetogenic effect of APs, expected role of antioxidants and anti-inflammatory drugs as therapeutics for improving the outcome in cases of long-term prescribed APs.

Cyclic AMP and calcium signaling are involved in antipsychotic-induced diabetogenic effects in isolated pancreatic β cells of CD1 mice

OBJECTIVES

Antipsychotics (APs) are medications used for different psychological disorders. They can introduce diabetogenic effects through different mechanisms, including cyclic adenosine monophosphate (cAMP) and calcium (Ca²⁺) signaling pathways. However, this effect is poorly understood. Therefore, this study aimed to evaluate the effect of three widely used APs (chlorpromazine, haloperidol, and clozapine) on cAMP and Ca²⁺ signaling.

METHODS

The local bioethics committee of Northern Border University approved the study. Pancreatic β-cells were isolated from male CD1 mice, and three drug stock solutions were made in different concentrations (0.1, 1, 10, and 100 μM). The levels of glucose-stimulated insulin secretion (GSIS) and cAMP as well as the activities of adenylyl cyclase (AC), cAMP-dependent protein kinase (PKA), guanine-nucleotide exchange protein activated by cAMP (Epac 1 and 2), Ca²⁺ mobilization, and Ca²⁺/calmodulin kinase II (CaMKII) were then determined using different methods.

RESULTS

APs were found to be cytotoxic to pancreatic β cells and caused a parallel and significant decrease in GSIS. APs significantly reduced the levels of cAMP in the treated cells, with an associated reduction in ATP production, CaMKII, PKA, and transmembrane AC activities as well as Ca²⁺ mobilization to variable extents. In addition, the gene expression results showed that APs significantly decreased the expression of both the active subunits AC1 and AC8, the PKA α and β subunits, Epac1 and Epac2 as well as the four main subunits of CaMKII to variable extents.

CONCLUSION

AP-induced alterations in the cAMP and Ca²⁺ signaling pathways can play a significant role in their diabetogenic potential.

Rapid-onset clozapine-induced hyperglycaemia: pathways of glycaemic dysregulation

Clozapine is an atypical antipsychotic used in refractory schizophrenia, also efficient in alleviating dyskinesia in Parkinson's disease. Despite its potency, this drug is associated with severe metabolic side effects, including increased risk for diabetes. We report the case of a 45-year-old overweight woman with Parkinson's disease who presented with rapid-onset hyperglycaemia within 2 months after starting clozapine for refractory dyskinaesia. She had a history of gestational diabetes. At presentation, her blood glucose level was 505 mg/dL and glycated haemoglobin 12.4%, with no catabolic symptoms. Clozapine was suspended and metformin was started, but adequate glycaemic control was achieved only with insulin therapy, along with exenatide and empagliflozin afterwards. We assume that clozapine acted as a trigger for rapid deterioration of glycaemic control through direct pathophysiological mechanisms, rather than an indirect slowly evolving weight gain-related metabolic syndrome pathway. Clinicians should be aware of this complication, enabling timely diagnosis and proper treatment.

Antipsychotics inhibit the mitochondrial bioenergetics of pancreatic beta cells isolated from CD1 mice

Antipsychotics (APs) are widely used medications with reported diabetogenic side effects. This study investigated the effect of commonly used APs, namely chlorpromazine (CPZ), haloperidol (HAL) and clozapine, on the bioenergetics of male CD1 mice isolated pancreatic beta cells as an underlying mechanism of their diabetogenic effects. The effect of APs on Alamar blue reduction, adenosine triphosphate (ATP) production and glucose-stimulated insulin secretion (GSIS) of isolated beta cells was evaluated. Then, the effects of APs on the activities of mitochondrial complexes and their common coding genes expression, oxygen consumption rate (OCR), mitochondrial membrane potential (MMP) and lactate production were investigated. The effects of APs on the mitochondrial membrane fluidity (MMF) and mitochondrial membrane fatty acid composition were also examined. Results showed that the tested APs significantly decreased cellular ATP production and GSIS of the beta cells. The APs significantly inhibited the activities of mitochondrial complexes and their coding gene expression, MMP and OCR of the treated cells, with a parallel increase in lactate production to different extents with the different APs. CPZ and HAL showed increased MMF and mitochondrial membrane polyunsaturated fatty acid content. In conclusion, the tested APs-induced mitochondrial disruption can play a role in their diabetogenic side effect.