Zantac infants dosage and side effects information

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What is Zantac?

Zantac is the brand name of a drug called Ranitidine. Ranitidine blocks acid production in the stomach so is an acid-suppressing medication.

Ranitidine belongs to a group of drugs called H2 antagonists, which mean they act by blocking H2 (a chemical that stimulates acid secretion in the stomach) which means less stomach acid is produced.

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Why is Zantac syrup (elixir) used in infants?

Zantac is used in babies with acid reflux (gastroesophageal reflux disease or gerd) - read more. It acts by stopping the acid that is causing the burning of the lower esophagus, which leads to the pain and discomfort seen in babies with gerd.

Zantac is also sometimes used in children who have chronic urticaria, which is an allergic skin rash. It is used when the usual anti-histamines (H1 blockers) like Cetirizine, are not enough. To read more on urticaria, click here

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What is the Zantac infants dosage?

For babies less than 6 months of age, the usual dose is:

1mg/kg/dose given 2 or 3 times per day, (1 milligram per kilogram of weight for each dose) - so a 4 kilogram baby would be on a dose of 4 mg two or three times per day, (if you have a solution of 75mg/5ml or 15mg/ml, then 4 mg is about 0.3 ml).

If this zantac infants dosage is not enough, higher doses have been used - up to 9mg/kg/day (divided into 2 or 3 doses).

If there is any renal (kidney) impairment, the dose should be decreased by 50%.

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What are the side effects of Zantac syrup (elixir) used in babies?

Infants tolerate Zantac quite well and side effects are uncommon. Sometimes babies can become a bit sleepy after taking Zantac. If high doses are used, it can sometimes cause diarrhea.

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Is it safe to give Zantac syrup (elixir) to babies?

Yes, it generally is. However, babies only need a medication like Zantac if they have GERD - gastroesophageal reflux disease. Most babies with simple vomiting or spilling, which is also known as gastroesophageal reflux, do not have acid that is causing burning or discomfort, and so do not need Zantac. Zantac is an acid suppressant medication, not an anti-vomiting medication.

If your baby doesn't have a problem with acid burning the esophagus, then your baby doesn't need Zantac. It is best to avoid medication if your baby doesn't really need it.

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Does Zantac stop gastroesophageal reflux?

No. Simple gastroesophageal reflux refers to the movement of the milk from the stomach to the mouth, via the esophagus, ie. vomiting. Zantac does not stop vomiting - it suppresses acid. In most cases, babies are not bothered by this simple gastroesophageal reflux (vomiting) as the milk neutralizes the stomach acid.

In some babies, the acid causes problems. Zantac reduces this acid, and that is why it is used in gastroesophageal reflux disease - GERD.

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Is Zantac useful for crying babies?

Only if the cause of the crying is acid, and there will usually be reflux as well. Some babies have "silent reflux" so they have an acid problem but don't vomit, so the reflux seems "silent". Zantac will help these babies.

Remember, that most babies who cry don't have "silent reflux" - it is more likely that they have colic (read more) and in these babies, Zantac will not work.

Sometimes your doctor will try Zantac for a crying baby in case he has "silent reflux" - if the Zantac doesn't work within a couple of weeks, then it probably isn't going to and it should be stopped. This is particularly true if increasing the zantac infants dosage has not helped. It means that acid isn't the problem.

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Does Zantac cause liver damage in babies?

Ranitidine (Zantac) can cause liver damage but this is rare. There are no case reports of liver damage in infants due to Zantac (Ranitidine) and generally it is a safe drug in infants and toddlers given at the correct dosage.

See your doctor if your baby or toddler becomes jaundiced (looks yellow) or develops dark urine and pale stools (poop, poo) while taking Ranitidine.

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  • Medicines for Children. RCPCH 2003
  • Epocrates @


To go to the top of the Zantac infants dosage and SE page, click here

To go to the Gastroesophageal Reflux Disease (gerd) page, click here

To go to the Medications page, click here

To go to the Vomiting page, click here

To go to the Crying page, click here

To return to the Home page, click here

Last reviewed 17 August 2011

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Dr Maud MD

Dr Maud MD (MBChB, FRACP, FRCPCH), a specialist pediatrician, provides health information and medical advice for parents of babies and toddlers. Read more about Dr Maud.

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