Hiccups: Casual Annoyance or Medical Concern?

Nearly everyone has experienced a hiccup at least once in their lives.

In most cases, hiccups onset with no known cause and are quite bothersome. Remedies have long been touted as effective treatments for acute hiccups include holding your breath, eating a spoonful of sugar, asking someone to scare you, and drinking a glass of water very quickly.

Are hiccups just mysteries that annoy us, or can there be serious implications associated with hiccups that require medical treatment?

What are hiccups?

Singultus, more commonly known as a hiccup, is an involuntary, spasmodic contraction of the intercostal muscles and diaphragm.¹ This contraction leads to sudden inspiration and nearly simultaneous closure of the glottis, resulting in the classic hiccup sound.

Hiccups are typically intermittent, with episodes usually lasting fewer than 24 hours. However, they can be persistent, lasting up to a month, or intractable, lasting longer than a month.

What causes hiccups?

Most commonly, acute hiccups are a result of gastric distension that may be caused by the consumption of carbonated beverages, overeating, or swallowing while chewing gum or smoking.² Less commonly, they may be caused by alcohol consumption, emotional stress, changes in temperature, or gasping from sudden excitement.

Persistent and intractable hiccups, on the other hand, are usually a result of a chronic pathophysiologic disorder, rather than an acute event. These etiologies are categorized by whether they originate in the central nervous system (CNS) or the peripheral nervous system (PNS).¹

CNS causes of hiccups include structural processes, most commonly neoplasms, multiple sclerosis, or head trauma. Infectious processes of the CNS include encephalitis and meningitis. Finally, CNS vascular processes including stroke and arteritis can also cause hiccups.

PNS causes of hiccups are most commonly a result of vagal or phrenic nerve irritation such as pharyngitis, malignancies near the brainstem, or goiter.

Hiccups have also been implicated as a symptom of myocardial infarction.³ Additionally, certain thoracic disorders including pneumonia, neoplasms, bronchitis, and trauma to the chest can cause hiccups, though in rare instances.¹

In addition to alcohol consumption, other drugs have been reported to cause hiccups. With the exception of case reports, documentation of hiccups as a medication side effect are from post-marketing studies in which patients have multiple comorbidities and are taking other concomitant medications.

For these reasons, it is difficult make a conclusive diagnosis that a particular drug induced hiccups. However, such cases have been reported for azithromycin and levodopa.^4,5

How do you treat hiccups?

Acute hiccups typically self-resolve without any treatment, but medical management may be indicated in patients with persistent or intractable hiccups. Treating the cause is the most obvious option; however, this can only be done if it is accurately identified.

If the cause of the hiccups is identified, then that should guide therapy. For example, many gastrointestinal causes of hiccups may be treated with acid suppressing agents such as H2-antagonists or proton pump inhibitors.

Physical maneuvers are usually the first-line treatment of hiccups when a definitive etiology cannot be identified. Such maneuvers are consistent with the aforementioned self-treatment strategies and are geared toward the physiology of a hiccup.^1,6 These include interrupting respiration by holding the breath or gasping, which can be induced by sudden freight.

Hiccups may be abated by irritation of the nasopharynx by drinking water quickly or eating dry sugar. Counter irritation of the diaphragm by pulling the knees into the chest and causing compression may also be an effective treatment.

Pharmacologic therapy may be considered in patients with persistent or intractable hiccups that fail physical maneuvers. Unfortunately, high-quality prospective data from controlled trials studying hiccup treatments are non-existent, so treatments are based off of mainly case reports and series.

The antipsychotic chlorpromazine is the only FDA-approved medication for the treatment of hiccups.⁷ It is dosed orally at 25 mg to 50 mg given 3 to 4 times daily, and no dosage adjustments are necessary for renal or hepatic impairment. Extrapyramidal adverse effects such as dystonic reactions or tardive dyskinesia are most common with prolonged antidopaminergic use.

The antidopaminergic gastrointestinal prokinetic agent metoclopramide also has reported efficacy in treating hiccups. Although it is not approved for hiccups, the drug’s efficacy has been observed with oral doses of 10 mg given 3 to 4 times daily.⁸ Similar to chlorpromazine, metoclopramide can cause tardive dyskinesia with prolonged use.

The skeletal muscle relaxant baclofen has also shown benefit in the treatment of hiccups by relieving spasticity of the diaphragm. It is mostly commonly dosed orally at 5 mg to 10 mg given 3 times daily.⁹ The most common related side effects are hypotonia, dizziness, and drowsiness.

Can hiccups have serious consequences?

Most episodes or bouts of hiccups last fewer than 48 hours and are generally more of a nuisance than harmful. Physical maneuvers are generally effective for intermittent hiccups, while drug therapy may treat persistent or intractable hiccups.

In some cases, however, severe intractable hiccups may lead to malnutrition, fatigue, dehydration, weight loss, and decreased quality of life. In this case, immediate medical treatment should be sought to identify the etiology and commence treatment.¹

Persistent hiccups in one teenage woman were reported to cause swallowing dysfunction, which ultimately resulted in acute respiratory failure.¹⁰ Additionally, a case report described persistent hiccups leading to nausea, syncope, and eventually cardiorespiratory failure in an elderly man.¹¹ In this case, it is likely that spinal cord lesions caused syncope and respiratory depression.

Unfortunately, no data suggests any specific markers that can be measured to predict whether or not hiccups can have serious consequences.

References

1. Kolodzik PW, Eilers MA. Hiccups (singultus): review and approach to management. Ann Emerg Med. 1991;20(5):565-73.

2. Lewis JH. Hiccups: causes and cures. J Clin Gastroenterol. 1985;7(6):539-52.

3. Davenport J, Duong M, Lanoix R. Hiccups as the only symptom of non-ST segment elevation myocardial infarction. Am J Emerg Med. 2012;30(1):266.e1-e2.

4. Jover F, Cuadrado JM, Merino J. Possible azithromycin-associated hiccups. J Clin Pharm Ther. 2005;30(4):413-6.

5. Gerschlager W, Bloem BR. Hiccups associated with levodopa in Parkinson’s disease. Mov Disord. 2009;24(4):621-2.

6. Friedman NL. Hiccups: a treatment review. Pharmacotherapy. 1996;16(6):986-95.

7. Chlorpromazine Hydrochloride Tablets [prescribing information]. Princeton, NJ: Sandoz; September 2010.

8. Wang T, Wang D. Metoclopramide for patients with intractable hiccups: a multicenter, randomized, controlled pilot study. Intern Med J. 2014;44(12a):1205-9.

9. Baclofen. Lexi-Comp [Internet]. Lexi-Comp Inc. 1978-2015. Accessed 25 November 2015.

10. Lin YR, Shih CC, Chen HC, Chen SJ. Am J Emerg Med. 2015;Epub ahead of print.

11. Okada S, Takarabe S, Nogawa S, Abe T, Morishita T, Mori M, Nishida J. Persistent hiccups followed by cardiorespiratory arrest. Lancet. 2012;380(9851):1444.