Risperidone-Induced Leukoneutropenia: Evidence from a Positive Rechallenge and Review of the Literature.

Antipsychotics can cause hematologic disorders, and they can have life-threatening consequences. Risperidone, less commonly associated with hematologic adverse effects, is an atypical antipsychotic medication used to treat conditions such as schizophrenia, bipolar disorder and irritability associated with autism. While risperidone primarily affects the central nervous system, it can have some hematologic adverse effects, although these are relatively rare. It is crucial to note that these side effects are not common, and most people taking risperidone do not experience hematologic disorders. The reporting of such disorders may be more frequent with clozapine compared to other atypical antipsychotics because clozapine treatment necessitates regular hematological monitoring 1.

Metronidazole-Induced Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) Syndrome With Parvovirus B19 Reactivation: A Pediatric Case.

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a severe and rare syndrome that causes life-threatening organ dysfunctions. Here, we present the case of a 10-year-old child who developed a pruritic erythematous eruption, fever, facial edema, and lymphadenopathy seven days after receiving intravenous metronidazole (20 mg/kg/day), vancomycin (50 mg/kg/day), and cefotaxime (200 mg/kg/day). Laboratory tests showed eosinophilia and liver damage as well as positive parvovirus B19 IgM and IgG indicating viral reactivation. Vancomycin was initially discontinued and later reintroduced with no ill effects. The patient was managed with topical corticosteroid emollients and cetirizine and improved within seven days of metronidazole withdrawal. Treatment with cefotaxime was continued and showed no adverse effects.

Drug-Induced Hypouricemia.

Hypouricemia is defined as a serum uric acid concentration of ≤ 2.0 mg/dL or 119 µmol/L. Hypouricemia may occur secondarily to a number of underlying conditions, including severe hepatocellular disease, neoplasia, defective renal tubular reabsorption of uric acid, inherited metabolic defect in purine metabolism, and drugs. Medications are an important cause of hypouricemia. They can cause hypouricemia by a variety of mechanisms. Drug-induced hypouricemia mostly occurs as overtreatment of hyperuricemia by urate-lowering therapies including xanthine oxidase inhibitors, uricosuric agents and uricases. Drugs not used in the treatment of gout may also lead to a decrease of uric acid levels. In this literature review, medications leading to hypouricemia are summarized with regard to their mechanism of action and clinical significance.