A hiccup is an involuntary reflex involving the respiratory muscles of the chest and diaphragm, mediated by the phrenic and vagus nerves and a central (brainstem) reflex center.
A single episode can last for a few seconds to as long as several days. If they last longer than 48 hours hiccups are termed persistent; longer than one month, intractable.

Etiologies range from stress/excitement to cancer, myocardial infarction, esophageal or gastric distension, liver disease, uremia, IV steroids, CNS lesions, and idiopathic. Irritation of the vagus nerve or diaphragm is a common pathophysiologic mechanism.

Management
Once hiccups have lasted beyond a time-limited annoyance, deciding on therapeutic intervention should be based on a thorough clinical assessment and, if possible, treatment directed at the underlying cause. A thorough history, review of medications, focused review of systems, and physical exam may help guide initial choice of treatment.
Many drug and nondrug treatments have been used, but there is little evidence of any one superior approach to management; virtually all current data are anecdotal.
The patient's prognosis, current level of function, and potential adverse effects from any proposed treatment should be considered.


Pharmacologic therapy
- Anti-psychotics: Chlorpromazine: 25-50 mg PO TID or QID - also by slow IV infusion (25-50 mg in 500-1000 ml of NS over several hours). Haloperidol: 2-5 mg (SubQ/PO) loading dose followed by 1-4 mg PO TID.
- Anticonvulsants: Gabapentin: 300-400 mg TID. Phenytoin: 200 mg slow IV push followed by 300 mg PO daily. Others: Valproic acid and Carbamazepine.
- Miscellaneous: Baclofen: 5 mg PO q8 hours. Metoclopramide : 10 mg PO QID. Nifedipine: 10 mg BID with gradual increase up to 20 mg TID.

Non-pharmacologic therapy
There are many well known, time-honored home remedies: gargling with water, biting a lemon, swallowing sugar, or producing a fright response.
Other approaches are directed at: a) vagal stimulation such as carotid massage or valsalva maneuver; b) interruption of phrenic nerve transmission via rubbing over the 5th cervical vertebra; or c) interrupting the respiratory cycle through sneezing, coughing, breath holding, hyperventilation, or breathing into a paper bag.
Other interventions, such as acupuncture, diaphragmatic pacing electrodes, or surgical ablation of the reflex arc can be considered when other treatments fail.

Adapted from Farmer C. Palliative Care Network of Wisconsin. Fast facts and concepts #81. Management of hiccups. Internet. Accessed on June 21, 2016.