Hiccups or singulata are rhythmic
involuntary movements of the diaphragm, caused by a variety of conditions that interfere with the functions of the nerve nuclei in the medulla and supra-spinal
hiccup center. Although
neurotransmitters and receptors involved in the pathophysiology of
hiccups are not defined well,
dopamine has been considered to play an important role. In some cases,
chlorpromazine or other
antipsychotics are used for the treatment of intractable
hiccups but their efficacy is often limited. This report involves an 18-year-old patient who experienced two episodes of intractable
hiccups triggered by stress, which lasted for weeks or even months. In both episodes,
haloperidol was initially used, but there was no significant effect. In contrast,
risperidone, the second-generation
antipsychotic that possesses a
dopamine-
serotonin antagonist property, completely abolished the
hiccups 6 hours after administration. This is one of few case reports in which two
antipsychotics were challenged for a single patient with
hiccups, and the effects of the drugs were obviously different. Our finding suggests that, in addition to dopaminergic system, the serotonergic systems may be involved in the pathophysiology of some
hiccup cases and that the
serotonin-acting
antipsychotics such as
risperidone should be considered as a choice in the
drug treatment of intractable
hiccups.