Background: A hiccup is the sudden onset of erratic diaphragmatic and intercostal muscle contraction immediately followed by laryngeal closure (1). In most cases, it is a self-limited condition that subsides spontaneously without any clinical significance (1). Hiccups are persistent if they last more than 48 hours, and intractable if they last more than a month (2). The self-limited hiccup is induced by the rapid stomach distension and irritation caused by overeating, eating too fast, ingesting spicy food, drinking carbonated drinks, aerophagia and sudden changes in ingested food temperature (3). There are many potential causes of hiccups, most of which are gastrointestinal and involve vagal and phrenic nerve stimulation (2). Causes of nerve irritation include pharyngitis, laryngitis, tumours, or neck cysts that stimulate the recurrent laryngeal nerve. The phrenic nerve irritation occurs to mediastinal masses, Goiter and abnormalities of the diaphragm (4). Many Gastrointestinal disorders cause phrenic nerve irritation. These include gastric distention, gastritis, gastroesophageal reflux, diaphragmatic eventration, peptic ulcer disease, pancreatitis, pancreatic cancer, gastric carcinoma, abdominal abscesses, gallbladder disease, inflammatory bowel disease, hepatitis, aerophagia, oesophagal distention, and esophagitis (5). Other causes include central nervous system disorders, metabolic disorders, psychogenic disorders, and drugs. Metabolic causes of hiccups include hypokalemia, hypocalcemia, hypocarbia (hyperventilation), and uremia (2). Moreover, 20% of Parkinsonian (PD) patients had frequent hiccups compared to 3% of the controls. Replacement therapy with dopamine agonists in PD patients is considered to induce certain episodes of hiccups; however, in others, hiccups may occur as a non-motor symptom of PD rather than as a side effect of anti-PD treatment (6). The dopamine agonists share a
high affinity for D3 receptors which may be involved in the hiccup reflex arc. Hence, drugs that block dopaminergic neurotransmission including chlorpromazine and metoclopramide may be employed in treating hiccup episodes (7).