Persistent Hiccups

A hiccup is an involuntary, spasmodic contraction of the diaphragm and inspiratory intercostal muscles, immediately followed by sudden closure of the glottis that produces the characteristic sound. Hiccups lasting under 48 hours are extremely common, self-limited, and rarely need active management. Persistent hiccups (48 hours to 1 month) and intractable hiccups (over 1 month) are a different clinical problem: they are driven by irritation somewhere along the hiccup reflex arc — the vagus and phrenic nerves, the brainstem "hiccup centre," or the efferent pathway to the diaphragm and glottis — and can be caused by an extraordinarily broad range of underlying conditions spanning the gastrointestinal tract, central nervous system, metabolic status, thorax and abdomen, and medication exposure.^[1] Left unaddressed, they can cause real functional harm — insomnia, inability to eat normally, exhaustion, and mood disturbance. Because management is most effective when directed at the underlying cause rather than at the hiccup reflex itself, identifying that cause — with a pharmacist-led medication review playing a central role — is the first and most important step, before any drug is chosen purely to suppress the hiccups.^[2]

What a hiccup episode looks like

Each hiccup is a brief, involuntary inspiratory spasm of the diaphragm (often with the external intercostal muscles), terminated abruptly by glottic closure — the two events together produce the characteristic "hic" sound. Episodes can recur several times per minute and are not under voluntary control once established.

• Gastrointestinal disease — gastroesophageal reflux, gastric distention or delayed emptying, esophagitis, subphrenic or intra-abdominal abscess, pancreatitis, bowel obstruction.
• Central nervous system disease — brainstem stroke, tumour, multiple sclerosis plaque, hydrocephalus, or traumatic brain injury affecting the medullary "hiccup centre" or its connections.
• Thoracic or mediastinal disease — pneumonia, pleuritis, pericarditis, myocardial infarction, mediastinal mass or lymphadenopathy.
• Recent abdominal or thoracic surgery, including esophagectomy and other procedures that irritate the diaphragm or phrenic nerve directly.
• Metabolic disturbance — uremia or renal failure, electrolyte disturbance (hyponatremia, hypocalcemia), hypoglycemia.
• ENT causes — pharyngitis, laryngitis, goitre, or a foreign body or hair irritating the external auditory canal (a branch of the vagus nerve supplies the ear canal).
• Malignancy — direct tumour invasion or compression of the vagus or phrenic nerve, the diaphragm, or the mediastinum.
• Medication exposure — see Assessment and Diagnosis for the specific drug classes most often implicated; a full medication and alcohol history is part of the standard work-up for every patient.
• Alcohol use.
• Older age and male sex.
• Occasionally no identifiable cause is found even after a thorough work-up; a psychogenic contributor is only considered after organic causes have been reasonably excluded.

History

Take a targeted history — including a complete medication list and alcohol use — looking specifically for a cause of vagus or phrenic nerve irritation, malignancy, or CNS or gastrointestinal disease.^[1] Ask about timing relative to any new medication, recent surgery, chemotherapy, or radiation; associated GI symptoms (heartburn, early satiety, dysphagia); and neurological symptoms.

Physical examination

General exam, a full neurological exam, and abdominal and chest exam, looking for signs pointing toward one of the causes above.

Investigations

If history and physical exam identify no abnormalities, it is reasonable to perform baseline laboratory tests (CBC, electrolytes, creatinine) and a chest x-ray.^[1] Further investigation — upper GI tract endoscopy, CT of the thorax and abdomen, abdominal ultrasound — is guided by findings from this initial approach rather than ordered routinely; do not pursue advanced imaging in a patient with an unremarkable history, exam, and initial screening tests. If gastroesophageal reflux disease is identified or strongly suspected as the underlying cause, treat it directly per standard GERD management (see the Gastroesophageal Reflux Disease chapter) rather than relying on an anti-hiccup drug alone — reflux-directed therapy is expected to resolve reflux-driven hiccups on its own. If all investigations are negative, or an identified cause cannot be corrected, a therapeutic trial to stop the hiccups directly is warranted.^[1]

• Stop or meaningfully decrease the frequency and intensity of hiccups, sufficient to resolve the functional impairment that brought the patient to care — restored sleep, ability to eat normally, and relief of exhaustion or distress.
• Identify and directly treat any underlying cause found, rather than relying on symptomatic suppression alone.
• Prevent recurrence.
• When chronic therapy is required, reach the lowest effective maintenance dose, ideally as a single daily dose.
• Avoid unnecessary long-term sedative, anticholinergic, or extrapyramidal drug burden when a better-tolerated agent achieves the same control.

Physical maneuvers

Techniques such as posterior pharyngeal wall stimulation with a finger, forced expiration against a closed glottis for about 10 seconds while seated, breath-holding, and breathing into a paper bag are widely used for acute hiccups, but there is no formal evidence supporting them specifically for persistent or intractable hiccups.^[1] Given their minimal risk, a brief trial is reasonable while pursuing the underlying-cause work-up, but do not rely on them as definitive therapy once hiccups have already become persistent.

Gastric decompression

If gastric distention is identified as the cause, gastric aspiration (for example, by nasogastric tube) is worth trying and can be both diagnostic and therapeutic.^[1]

Acupuncture

Poor-quality studies have reported temporary or permanent relief of intractable hiccups with acupuncture, but no randomized, placebo-controlled trials have been published — treat this as a low-evidence adjunct a patient may choose to pursue, not a recommended first-line intervention.^[1]

Continuous cervical epidural block

Has shown a high success rate in case series when multiple sessions (usually 2-3) are used. Reserve for refractory cases under specialist (anesthesia or pain-service) direction after pharmacotherapy trials have failed — see Treatment Failure and Next Step.^[1]

Pregnancy

Persistent or intractable hiccups have not been specifically studied in pregnancy. Identify and treat any reversible underlying cause first, since this avoids drug exposure altogether whenever possible. If pharmacotherapy is needed, metoclopramide has the most established pregnancy safety experience among the agents in this chapter, given its extensive use for nausea and vomiting in pregnancy; reserve chlorpromazine, baclofen, and gabapentin for when metoclopramide is inadequate or not tolerated, and involve obstetric care in the decision.

Breastfeeding

Metoclopramide is compatible with breastfeeding. Baclofen and gabapentin are both present in breast milk in small amounts and are generally considered compatible with breastfeeding, with infant monitoring for sedation. Chlorpromazine can cause infant sedation — use the lowest effective dose and monitor the infant if used during breastfeeding.

Pediatrics

Persistent or intractable hiccups are rare in children, and the evidence base for pharmacotherapy is even more limited than in adults. Not established for routine pediatric use with any of the agents in this chapter — use only under specialist direction with individualized, weight-based dosing rather than adult fixed doses.

Renal impairment

Baclofen is renally excreted — reduce the dose substantially in renal impairment (for example, start 2.5 mg PO BID rather than the usual 5 mg BID starting dose); neurotoxicity has been reported in patients with renal failure given standard doses.^[10] Gabapentin is also renally cleared and needs dose adjustment for reduced renal function — see the Drug Database entry for the full adjustment schedule.

Hepatic impairment

Chlorpromazine is hepatically metabolized — use caution and consider a lower starting dose in significant hepatic impairment.

Older adults

The population most affected by persistent and intractable hiccups.^[1] Older adults are more susceptible to the sedative, anticholinergic, and extrapyramidal effects of chlorpromazine, haloperidol, and metoclopramide, and to the sedation and fall risk of baclofen and gabapentin — start at the low end of the dosing range, titrate slowly, and reassess for these effects at every dose change.

With an effective drug, hiccups generally stop abruptly within a few hours of starting therapy; in some cases the frequency and severity decrease more gradually over days rather than stopping abruptly.^[1] Once hiccups have been controlled for 1-3 days, begin tapering the dose; if hiccups do not return, continue tapering to discontinuation. If hiccups return during or after tapering, return to the lowest dose that reliably suppresses them — maintenance therapy, ideally as a single daily dose, is required in some patients.^[2] When a drug is ineffective, there is no need to continue treatment beyond 3 days before switching approach. Monitor for the specific adverse effects of whichever agent was chosen — extrapyramidal symptoms and QTc prolongation with the dopamine antagonists, sedation and renal-related neurotoxicity with baclofen, sedation and ataxia with gabapentin — and reassess in parallel whether any identified underlying cause is actually resolving, not only whether the hiccups themselves have stopped.

1. Reconfirm no underlying cause was missed on the initial history, exam, or investigations — specifically re-review the full medication list for a causative drug (a corticosteroid, benzodiazepine, opioid, or other agent) that has not yet been stopped, reduced, or rotated.
2. If a first-line agent was genuinely ineffective after an adequate 2-3 day trial at an appropriate dose, stop it and switch to a different pharmacologic class rather than continuing to escalate the same drug indefinitely.
3. If GERD or another identified cause was targeted directly but hiccups have not resolved, reassess whether that cause has actually been adequately controlled before assuming the anti-hiccup drug itself has failed.
4. Pursue further investigation (upper GI tract endoscopy, CT of the thorax and abdomen, abdominal ultrasound) if not already done and an occult cause remains plausible.
5. For hiccups that remain refractory despite adequate sequential trials of at least 2 pharmacologic agents from different classes and no correctable cause found, refer for continuous cervical epidural block (typically 2-3 sessions under specialist direction).^[1]
6. Phrenic nerve block is reserved for cases where all other treatment modalities — pharmacologic and the interventions above — have genuinely failed; refer to an anesthesia or pain-management specialist rather than attempting this as an earlier-line option.^[11]

• Starting an anti-hiccup drug before completing a targeted history (including a full medication and alcohol review) and physical exam — most persistent hiccups have an identifiable, and sometimes directly treatable, cause.
• Missing a medication-induced cause because the causative drug (a corticosteroid, benzodiazepine, or opioid) was started well before the hiccups began and the connection was never explicitly checked.
• Using benzodiazepines to try to calm or sedate a patient with persistent hiccups — they can precipitate or worsen hiccups rather than relieve them.
• Continuing an ineffective drug trial beyond 2-3 days instead of stopping and switching to a different class.
• Stopping an effective agent abruptly instead of tapering — particularly relevant for baclofen, which should be tapered gradually once hiccups are controlled.
• Failing to reduce the baclofen dose in renal impairment — a recognized cause of neurotoxicity at standard doses.
• Ordering extensive imaging (CT thorax-abdomen, endoscopy) reflexively in a patient with an unremarkable history, exam, and initial screening labs/chest x-ray, instead of letting findings from that initial work-up guide further testing.
• Treating an identified reversible cause, such as reflux disease, with an anti-hiccup drug alone instead of treating the underlying cause directly.

How to use this table: Doses are adult doses and require patient-specific confirmation (renal/hepatic function, weight, allergy history). Pediatric dosing is weight-based per the current product monograph unless stated. Drug pricing is intentionally omitted. Select any drug name to open its complete Pharmasist Drug Database page.

Dopamine Antagonists

The longest-studied class for persistent/intractable hiccups; chlorpromazine and haloperidol have case-report/case-series-level evidence, while metoclopramide has randomized, placebo-controlled trial support.

GABA-B Agonist

One of only two agents (with metoclopramide) studied in randomized, placebo-controlled trials for intractable hiccups, and — together with gabapentin — increasingly favoured as an initial choice given better long-term tolerability than the dopamine antagonists.

Anticonvulsant

Observational (case-series) evidence supports gabapentin specifically; favoured alongside baclofen as an initial choice for the same tolerability reasons.

Other Agents — Case-Report-Level Evidence Only

Reserved for when the preferred agents above have failed or are contraindicated. Hiccup-specific dosing has not been established in controlled trials for any of these agents — dose within the drug's standard indication-specific range under specialist guidance rather than assuming the doses used for hiccups above apply.