Dopaminergic Drugs and Valproate-associated Refractory Hyponatremia Over Levosulpiride-induced Parkinsonism in an Elderly Female Patient When Deprescribing was the Only Therapy

Introduction: Prescribing cascade is a condition in which a drug administered to a patient causes an adverse reaction that is misinterpreted as a new condition, resulting in the addition of a new drug. Case Presentation: Here, we report the case of an elderly female patient who suffered from metabolic, neurologic, and urinary consequences of a prescribing cascade of antiemetic, antiepileptic, and dopaminergic drugs. While levosulpiride caused Parkinsonian symptoms, the dopaminergic drugs and valproate caused refractory hyponatremia followed by altered sensorium, and clidinium contributed to urinary retention. Conclusion: The case highlights the need to be vigilant for adverse consequences of the prescribing cascade, especially for antiemetic drugs, such as levosulpiride, because of its propensity to induce extrapyramidal reactions in older patients. In cases of refractory hyponatremia, a trial of de-challenge of valproate and dopaminergic drugs should be considered. In addition, the identification and removal of the culprit drugs can rescue the patient from a disabling cycle of adverse drug reactions.