Does azithromycin cause vomiting? Understanding the Common Side Effect

October 12, 2025 •

4 min read

Vomiting is a reported side effect in up to 13% of patients taking azithromycin, varying by dosage [1.2.5]. Understanding why this occurs and how to manage it is key for completing treatment. So, does azithromycin cause vomiting? Yes, it is a recognized reaction.

Quick Summary

Vomiting is a common gastrointestinal side effect of azithromycin, with frequency depending on dosage. This reaction is often due to the drug's impact on gut motility. Management involves taking it with food and staying hydrated.

Key Points

Vomiting is a Common Side Effect: Vomiting occurs in 2% to 13% of patients taking azithromycin, with the frequency influenced by the dosage [1.2.1, 1.2.5].
Mechanism is Gut Motility: Azithromycin causes vomiting by stimulating motilin receptors in the gut, which increases gastrointestinal contractions [1.5.3].
Dosage Matters: Higher doses, such as a single 2-gram dose, are associated with a higher incidence of vomiting and other GI side effects compared to standard multi-day regimens [1.2.7].
Management Strategies are Key: Taking the medication with food (for tablets), staying hydrated, and eating a bland diet can help minimize or prevent vomiting [1.3.1, 1.3.3].
Better Tolerated Than Older Macrolides: Azithromycin generally has fewer and less severe gastrointestinal side effects compared to older macrolides like erythromycin [1.5.3].
Consult a Doctor if Vomiting Occurs Soon After Dose: If vomiting happens within an hour of taking azithromycin, a doctor should be contacted to determine if a repeat dose is necessary [1.2.6].
Pediatric Considerations: Side effects in children are similar to adults, but parents should watch for forceful vomiting in infants, as it could be a sign of a rare but serious condition [1.6.8].

The Link Between Azithromycin and Gastrointestinal Distress

Azithromycin, a widely prescribed macrolide antibiotic known by brand names like Zithromax (Z-Pak), is effective against a variety of bacterial infections [1.4.4, 1.6.4]. However, its use is frequently associated with gastrointestinal (GI) side effects, most notably diarrhea, nausea, abdominal pain, and vomiting [1.2.2]. The frequency of these adverse reactions can vary significantly depending on the dosage regimen. For instance, in multi-dose regimens, vomiting may occur in 2% to 7% of patients [1.2.2]. This rate can increase with higher single-dose treatments; a single 2-gram dose of azithromycin was associated with vomiting in about 7% of patients [1.2.1].

Why Does Azithromycin Cause Vomiting?

The primary reason azithromycin and other macrolide antibiotics cause GI upset is their effect on gut motility [1.5.3]. These drugs can act as agonists for motilin receptors in the gastrointestinal tract. Motilin is a hormone that stimulates GI motility, and by mimicking its action, azithromycin can cause increased contractions, leading to symptoms like abdominal cramping, diarrhea, nausea, and vomiting. This effect is dose-dependent, which explains why higher doses, such as the single 2-gram dose used for certain infections, are linked to a higher incidence of these side effects [1.2.7].

The formulation of the medication can also play a role. For example, the extended-release suspension (Zmax) is best taken on an empty stomach, which might affect tolerance in some individuals [1.2.9].

Managing and Preventing Azithromycin-Induced Vomiting

While GI side effects can be unpleasant, there are several effective strategies to minimize or prevent them, helping ensure you can complete your full course of antibiotics.

Take With Food: For standard azithromycin tablets, taking the medication with food can help reduce stomach upset, nausea, and the likelihood of vomiting [1.3.3, 1.3.7]. However, it is crucial to follow the specific instructions for your prescription, as some formulations like the extended-release suspension should be taken on an empty stomach [1.2.9].
Stay Hydrated: Drinking plenty of fluids, like water or squash, can help prevent dehydration, especially if you are experiencing vomiting or diarrhea [1.3.1].
Eat Simple Meals: While taking the antibiotic, stick to bland, simple meals and avoid rich, spicy, fried, or acidic foods that can further irritate your stomach [1.3.1, 1.3.5]. The BRAT diet (bananas, rice, applesauce, toast) or other mild foods like crackers and boiled potatoes can be beneficial [1.3.5].
Consider Probiotics: Some healthcare providers may suggest taking probiotics or eating yogurt with live cultures to help maintain healthy gut flora, which can be disrupted by antibiotics [1.3.5].

If vomiting occurs within an hour of taking a dose, it is important to contact your doctor right away. They will advise if you need to take another dose, as the medication may not have been fully absorbed [1.2.6, 1.6.3]. Do not take another dose unless instructed to do so.

Azithromycin in Special Populations

Children

The types of side effects seen in pediatric patients are comparable to adults, but incidence rates can differ based on the dosage and the condition being treated [1.2.1]. For example, when treating a throat infection or tonsillitis in children, the vomiting rate can be around 6% [1.6.1]. For ear infections, it can be up to 5% with a 1-day course [1.6.1]. In infants under 6 weeks, azithromycin has been linked to a rare condition called infantile hypertrophic pyloric stenosis (IHPS), which causes forceful vomiting; parents should contact a doctor if an infant becomes irritable or vomits while feeding [1.6.2, 1.6.8].

Geriatric Patients

Elderly patients may be more susceptible to certain side effects of azithromycin, particularly heart rhythm issues like torsades de pointes [1.2.1]. While GI issues are common across all age groups, older adults should be mindful of staying hydrated and reporting severe or persistent symptoms to their healthcare provider.

Comparison with Other Antibiotics

When compared to other antibiotics, particularly older macrolides like erythromycin, azithromycin is generally considered to have better gastrointestinal tolerance [1.5.1, 1.5.3]. Studies have shown that the incidence of GI side effects with clarithromycin and azithromycin (around 12-13%) is significantly lower than with erythromycin (which can be as high as 32%) [1.5.3]. This improved tolerability is one of the key advantages of azithromycin [1.5.4].


Feature	Azithromycin	Erythromycin	Amoxicillin (Penicillin class)
Common GI Side Effects	Diarrhea, nausea, abdominal pain, vomiting (2-13%) [1.2.1, 1.2.5]	High incidence of GI upset (up to 32%) due to strong motilin receptor stimulation [1.5.3]	Diarrhea, nausea, vomiting
Mechanism of GI Upset	Stimulates gut motility [1.5.3]	Strong stimulation of gut motility [1.5.3]	Disruption of normal gut flora
Administration with Food	Generally can be taken with food to reduce upset (formulation dependent) [1.3.7]	Often taken with food to minimize GI distress	Can be taken with or without food
Overall Tolerability	Better tolerated than erythromycin [1.5.2]	Poorer GI tolerability compared to newer macrolides [1.5.3]	Generally well-tolerated, but can cause rash and diarrhea

Conclusion

Yes, azithromycin can and does cause vomiting as a common, well-documented side effect. This is primarily due to its stimulating effect on gastrointestinal motility. The frequency of vomiting varies with dosage but typically ranges from 2% to 13% [1.2.1, 1.2.5]. Fortunately, this side effect can often be managed by taking the medication with food (for most formulations), staying hydrated, and modifying your diet. Compared to older macrolides like erythromycin, azithromycin is better tolerated [1.5.3]. If vomiting is severe, persistent, or occurs shortly after taking a dose, it is essential to consult a healthcare provider for guidance.

For more information from an authoritative source, you can review the drug information available at MedlinePlus [1.2.6].

Frequently Asked Questions

The frequency of vomiting when taking azithromycin ranges from 2% to 7% for typical multi-dose regimens and can be as high as 13% depending on the dose and condition being treated [1.2.2, 1.2.5].

For most azithromycin tablet formulations, taking it with food can help reduce nausea and vomiting [1.3.7]. However, always check the label, as some forms like the extended-release oral suspension (Zmax) should be taken on an empty stomach [1.2.9].

If you vomit within one hour of taking your dose, you should contact your healthcare provider immediately. They will advise you on whether you need to take another dose, as the medication may not have been absorbed [1.2.6].

Children experience similar side effects to adults. The rate of vomiting in children can range from 2% to 6% depending on the infection being treated [1.6.1]. A single high dose carries a greater risk of vomiting than a multi-day course [1.6.4].

To reduce nausea, try taking the medication with a simple meal, avoid spicy or rich foods, and stay well-hydrated by sipping water throughout the day [1.3.1, 1.3.3]. Ginger or peppermint tea may also help soothe nausea [1.3.6].

Azithromycin is generally better tolerated and causes fewer gastrointestinal side effects than older macrolide antibiotics like erythromycin [1.5.3]. Its side effect profile is different from other classes like penicillins (e.g., amoxicillin).

Side effects like nausea and vomiting are typically temporary and should resolve within a few days after you finish taking the medication [1.3.5]. If symptoms are severe or persist, contact your doctor.