Dose-dependent L-dopa/carbidopa-induced hyponatremia presenting with hiccups.

Levodopa (L-dopa) is the most effective antiparkinsonian agent and is well tolerated at all stages of the disease. However, both motor and nonmotor adverse events are reported with the use of L-dopa. Electrolyte imbalances such as hyponatremia and hiccups with L-dopa/carbidopa are very rare. For the first time, we are reporting a case of L-dopa/carbidopa-induced hyponatremia and hiccup cooccurring in a 75-year-old male. He symptomatically improved after reducing the dose of levodopa/carbidopa, indicating a dose-dependent nature of these adverse events. Clinicians who prescribe L-dopa/carbidopa should be mindful of the potential for precipitating SIADH and hiccups, especially in elderly patients.