Azithromycin and Rice Allergy: Do Azithromycin Products Contain Rice-Derived Ingredients, and Are They Safe?

Azithromycin tablets generally do not list rice-derived ingredients (such as rice starch) in their official inactive ingredient lists, and many formulations instead use corn starch or pregelatinized (maize) starch and other common excipients. ^{[1] [2]} However, excipients can vary by manufacturer and product version, so it is wise to verify the specific brand and strength you have. ^{[3] [4]}

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What Inactive Ingredients Are Commonly Used in Azithromycin?

Many azithromycin tablets use the following excipients, none of which are rice-derived:

• Corn starch or partially pregelatinized maize starch. ^{[1] [2]}
• Dibasic calcium phosphate (anhydrous). ^{[1] [3]}
• Croscarmellose sodium (a disintegrant). ^{[1] [4]}
• Hypromellose (film coating polymer). ^{[1] [2]}
• Magnesium stearate (lubricant). ^{[1] [2]}
• Lactose monohydrate and/or microcrystalline cellulose (fillers; present in some labels). ^{[1] [3]}
• Film coat systems such as Opadry II containing polyvinyl alcohol, polyethylene glycol, titanium dioxide, and talc. ^{[2] [5]}

These official label examples show corn/maize starch rather than rice starch. ^{[1] [2]} Some other azithromycin labels list “pregelatinized starch” without specifying the source; in marketed azithromycin tablets, this typically refers to corn/maize starch. ^{[4] [6]}

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Representative Label Snapshots

The table below summarizes inactive ingredients from several azithromycin labels to illustrate variability across manufacturers. These examples do not list rice-derived excipients.

Product example	Active form	Starch/excipient notes	Other excipients (selected)
Azithromycin tablet, film-coated (setid c6c94568…)	Azithromycin	Corn starch specified	Dibasic calcium phosphate (anhydrous), croscarmellose sodium, hypromellose, lactose monohydrate, magnesium stearate. [1]
Azithromycin dihydrate tablets with Opadry II	Azithromycin dihydrate	Partially pregelatinized maize starch	Colloidal silicon dioxide, croscarmellose sodium, dibasic calcium phosphate, hypromellose, magnesium stearate, sodium lauryl sulfate; Opadry II coat contains polyvinyl alcohol, PEG, TiO2, talc. [2]
Azithromycin monohydrate tablets	Azithromycin monohydrate	Corn starch	Dibasic calcium phosphate (anhydrous), croscarmellose sodium, hypromellose, lactose monohydrate, magnesium stearate, microcrystalline cellulose. [3]
Azithromycin tablets (other label)	Azithromycin dihydrate, USP	Pregelatinized starch (noted generically; commonly corn)	Croscarmellose sodium, dibasic calcium phosphate (anhydrous), hypromellose, magnesium stearate, polyethylene glycol, sodium lauryl sulfate, titanium dioxide. [4]

These examples indicate corn/maize starch or generic pregelatinized starch rather than rice-derived materials. ^{[1] [2]} Generic pregelatinized starch in azithromycin labels is commonly corn-based in practice. ^{[4] [6]}

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Safety for Individuals with Rice Allergy

• Rice allergy is uncommon but documented, and reactions are usually triggered by rice proteins in foods. ^[7] Azithromycin tablets do not typically contain rice proteins or rice starch according to multiple labels, which suggests they may be acceptable for individuals with rice allergy. ^{[1] [2]}
• However, excipients can vary by brand and country, and labels sometimes use generic terms (“pregelatinized starch”) without naming the source. ^[4] Because of this variability, someone with a strict rice allergy should verify the exact product’s excipient list before use. ^[8]
• Pharmaceutical excipients are not always inert for everyone, and sensitive individuals can react to dyes, starches, lactose, or other additives. ^[8] Manufacturers are not universally required to highlight all potential allergen sources, which is why checking the specific label or contacting the manufacturer can be helpful. ^[9]

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Practical Steps to Reduce Risk

• Check the exact product label: Look for “corn starch,” “maize starch,” or “pregelatinized starch;” absence of rice starch is reassuring. ^{[1] [2]}
• Ask your pharmacist to confirm the excipient source for your brand and strength, especially if the label lists “pregelatinized starch” without specifying corn/maize. ^[4]
• Consider a brand that explicitly lists corn/maize starch if you want extra assurance. ^[1]
• If you have a history of severe anaphylaxis to rice, discuss with your clinician and consider observing the first dose in a safe setting or choosing a formulation with clearly stated excipients. ^{[7] [8]}

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Key Takeaways

• Most azithromycin tablet labels list corn/maize starch, not rice starch. ^{[1] [2]}
• Rice-derived excipients are not typically present in azithromycin tablets, making them likely acceptable for individuals with rice allergy. ^{[1] [2]}
• Because excipients vary, verify the exact product’s inactive ingredients or consult the manufacturer/pharmacist for confirmation if you need absolute certainty. ^{[4] [8]}