Is Promethazine Good for Hiccups? Examining Efficacy and Safety

October 10, 2025 •

4 min read

While one case study reported a patient's intraoperative hiccups stopping after a single intravenous dose of promethazine, it is generally not considered a standard or preferred treatment for chronic hiccups. The use of promethazine for hiccups lacks significant evidence and carries potential risks, making other medications and non-pharmacological methods the standard of care.

Quick Summary

Promethazine is not the standard treatment for hiccups due to its unproven efficacy and notable side effects. Alternative medications with better-established success are preferred by clinicians for persistent hiccup cases.

Key Points

Not a First-Line Choice: Promethazine is not recommended as a first-line treatment for chronic or persistent hiccups due to a lack of strong evidence.
Significant Side Effects: The medication carries notable side effects, including severe drowsiness, dizziness, confusion, and a risk of serious extrapyramidal symptoms.
Boxed Warning for Children: The FDA has a boxed warning against using promethazine in children under 2 years old due to the risk of potentially fatal respiratory depression.
Chlorpromazine is FDA-Approved: Confusion with chlorpromazine, another phenothiazine, sometimes occurs; however, chlorpromazine is the only medication approved by the FDA specifically for intractable hiccups.
Safer Alternatives Exist: Effective and safer alternatives exist for chronic hiccups, including baclofen, chlorpromazine, and gabapentin.
Non-Pharmacological First: Simple home remedies should be tried for short-term hiccups before considering any medication.
Medical Consultation is Key: For persistent hiccups, a medical evaluation is necessary to diagnose any underlying cause and receive an appropriate treatment plan.

Understanding the Hiccup Reflex

Hiccups, medically known as singultus, are involuntary contractions of the diaphragm followed by a rapid closing of the vocal cords, which produces the characteristic 'hic' sound. While short-lived hiccups are common and harmless, persistent hiccups (lasting more than 48 hours) or intractable hiccups (lasting over a month) can be distressing and indicate an underlying medical condition. The exact mechanism behind the hiccup reflex is complex but is believed to involve a reflex arc controlled by the brainstem, with pathways that can be influenced by various stimuli and pharmacological agents.

Promethazine: Approved Uses and Mechanism

Promethazine (brand name Phenergan) is an antihistamine medication primarily used to treat and prevent allergies, motion sickness, and nausea. It also has sedative properties and can be used for short-term sedation. Its mechanism of action involves blocking histamine H1 receptors and also acting as a dopamine antagonist in the brain. These properties are effective for its approved indications but do not directly target the primary cause of hiccups.

Why Promethazine is Not a First-Line Treatment for Hiccups

Despite its pharmacological profile and older anecdotal reports, promethazine is not the preferred treatment for persistent or intractable hiccups for several key reasons:

Lack of Evidence: Unlike other medications that have been studied in clinical trials for hiccups, there is a lack of robust evidence to support promethazine's efficacy for this specific purpose. The single case study showing success involved an intravenous dose during surgery, which is not applicable to most patients with chronic hiccups.
Significant Side Effect Profile: Promethazine is associated with several notable side effects that may outweigh the potential, unproven benefit for hiccups. These include severe drowsiness, confusion, dizziness, dry mouth, and, less commonly, serious issues like extrapyramidal symptoms (uncontrolled movements) and neuroleptic malignant syndrome.
Distinction from Chlorpromazine: Confusion often arises between promethazine and chlorpromazine. While both are phenothiazines, chlorpromazine is the only medication with specific FDA approval for treating intractable hiccups and is supported by more clinical evidence. Older reports may have contributed to the misconception that promethazine is a suitable replacement, but this is not the case.

Preferred Medications for Intractable Hiccups

For hiccups that last longer than 48 hours and do not respond to simple home remedies, healthcare providers typically prescribe medications with a better-documented efficacy profile. These include:

Chlorpromazine: As the only FDA-approved drug for intractable hiccups, it is often considered first-line therapy. It works by blocking dopamine receptors in the brain.
Baclofen: A muscle relaxant that has shown effectiveness in treating hiccups. It can be particularly useful when nerve signals are a contributing factor.
Gabapentin: An anticonvulsant that can be used off-label for treating persistent hiccups, especially in cases where other medications fail.
Metoclopramide: A prokinetic agent that can help by affecting gastrointestinal motility, addressing cases where gastric issues trigger hiccups.

Comparative Table: Hiccup Medications


Medication	Primary Indication	Efficacy for Hiccups	Key Side Effects
Chlorpromazine	Psychosis, Mania, Nausea	Proven for intractable hiccups (FDA-approved)	Sedation, dizziness, low blood pressure, tardive dyskinesia
Promethazine	Allergies, Nausea, Sedation	Limited evidence; generally not recommended	Sedation, dizziness, dry mouth, confusion, extrapyramidal symptoms
Baclofen	Muscle Spasms	Strong evidence; widely used for chronic hiccups	Drowsiness, dizziness, nausea, weakness
Gabapentin	Seizures, Nerve Pain	Effective in many cases, often used off-label	Drowsiness, dizziness, fatigue, coordination problems

Potential Risks and Side Effects of Promethazine

Beyond general ineffectiveness for hiccups, promethazine carries specific safety concerns, particularly for certain populations. The FDA has issued a boxed warning for the use of promethazine in children under 2 due to the risk of fatal respiratory depression. For adults, common side effects include:

Central Nervous System (CNS) Depression: Promethazine can cause significant drowsiness, dizziness, and confusion, which can impair a person's ability to drive or operate machinery safely.
Anticholinergic Effects: These include dry mouth, blurred vision, and difficulty with urination.
Extrapyramidal Symptoms (EPS): In some cases, promethazine can cause involuntary muscle movements, which can be a serious and disturbing side effect.
Injection Site Damage: When administered intravenously, promethazine can cause severe tissue injury, including nerve damage.

Alternative Non-Pharmacological Treatments

For mild, short-term hiccups, several non-pharmacological interventions are worth trying before considering medication:

Dietary adjustments: Avoiding spicy foods, carbonated drinks, or overeating can help prevent triggers.
Breathing maneuvers: Holding your breath for a short period, breathing into a paper bag, or performing the Valsalva maneuver can sometimes interrupt the hiccup reflex.
Pharyngeal stimulation: Sipping ice water, gargling with water, or swallowing a teaspoon of sugar may help.

Conclusion: The Final Verdict on Promethazine for Hiccups

While promethazine may have been mentioned in historical or isolated contexts for hiccups, it is not a recommended or reliable treatment. Modern pharmacology and clinical guidelines favor safer and more effective alternatives with better-established evidence for managing persistent and intractable hiccups. The risks associated with promethazine, including its potent sedative effects and other potentially serious side effects, far outweigh its unproven benefits for this condition. For anyone experiencing persistent hiccups, the best course of action is to consult a healthcare professional to identify the underlying cause and determine the most appropriate and safest treatment plan.

For further information on FDA-approved uses and warnings, consult resources like the FDA's drug information database.

Frequently Asked Questions

While both are phenothiazine drugs, chlorpromazine is the only medication in this class that is FDA-approved for treating intractable hiccups and has a better evidence base for this condition. Promethazine, on the other hand, is primarily for allergies and nausea and is not a recommended treatment for hiccups.

Yes, significant drowsiness is one of the most common and prominent side effects of promethazine. The sedative effects can be potent and may interfere with daily activities, including driving and operating machinery.

Common medical alternatives for persistent hiccups include chlorpromazine (the only FDA-approved drug for this use), baclofen, gabapentin, and metoclopramide. The most appropriate choice depends on the patient's individual condition and other health factors.

Promethazine carries a boxed warning from the FDA for use in children under 2 years old due to the risk of potentially fatal respiratory depression (slowed or stopped breathing). This makes it unsafe for infants and young children.

If hiccups last for more than 48 hours, they are considered persistent and warrant medical evaluation. A doctor can help determine if there is an underlying cause and recommend a safe and effective treatment plan.

Yes, many simple methods can help stop short-term hiccups, such as drinking cold water, holding your breath, or breathing into a paper bag. For chronic cases, these might provide temporary relief but are not a long-term solution.

Yes, promethazine can cause extrapyramidal symptoms (EPS), which are involuntary movement problems. This is a potentially serious side effect and a reason why it is not typically chosen for hiccups.