Zantac: Indications, Side effect, Dosage, Warning

The generic name for Zantac tablet is Ranitidine HCL.

Ranitidine belongs to the group of drugs histamine-2 blockers. It works by decreasing the amount of gastric acid that the stomach produces. This medicine is sold over the counter even without a prescription.


Zantac is used to treat stomach and intestinal ulcers and also is used to prevent ulcers from coming back. This medication addresses certain oesophagus and stomach issues. Zantac relives heartburn that is associated with sour stomach and acid indigestion. It is used to treat GERD and other conditions such as injury to food pipe that cause the stomach acid to back up into the oesophagus and thus causing heartburn.

Ranitidine is also prescribed in conditions such as Zollinger- Ellison syndrome where there is too much production of stomach acid.

How Zantac Medicine Is Taken: Dosage And Administration

Over the counter ranitidine comes as a tablet that is to be taken orally once or two times in a day. In some condition, it is also prescribed four times a day. Take medicine as directed by the doctor.

Your medical condition determines the dosage and treatment length. In children, dosage may be decided depending on body weight.

If you need to take this medicine daily, then try to make it at the same time every day to get most of its benefit. Do not increases or decrease the dose than prescribed without doctor’s recommendation.

For adults and children above 12 years who take Zantac without prescription for self-treatment of heartburn and indigestion, take one tablet orally with a glass of water. It is to be taken 30 to 60 minutes before eating or drinking foods that lead to heartburn. Always read and follow the directions on the package label or prescriptions. Read the manufacturer’s package instructions and do note expiry date. If you do not understand anything ask your pharmacist to explain.

Do not take more than two tablets within 24 hours unless your health care provider directs it.

Unless your doctor recommends, do not take over the counter ranitidine for more than two weeks. If symptoms of acid indigestion, sour stomach and heartburn last longer than two weeks even after taking medicine, see your health care provider.

Zantac in form of granules and effervescent tablets should be dissolved in the water before intake. 25-milligram effervescent tablet is to be dissolved in 1-teaspoon water and 150-milligram effervescent tablet is to be dissolved in 6-8 ounce of water. The effervescent tablet should not be allowed to dissolve on the tongue. Do not chew, break or crush it. As Zantac effervescent tablets contain phenylalanine better talk to your doctor before you use ranitidine in this form.

Mix Zantac granule form with about 6-8 ounces of water and before taking.

Zantac liquid medicine is to be taken with a special dose-measuring cup or spoon as advised by your doctor.

Warnings and Precautions

Do not take ranitidine without consulting your doctor under the conditions discussed below:

  • Heartburn over 3 months. Please note this may be a sign of severe health issues.
  • If you experience sweating, dizziness and light-headedness
  • Shoulder pain or chest pain with pain spreading to neck, arm and shoulder along with shortness of breath, sweating or light-headedness.
  • Frequent wheezing with heartburn
  • Recurrent chest pain
  • Nausea and vomiting
  • Stomach pain
  • Unexplained weight loss

Children under 12 years of age should not be given ranitidine unless doctor prescribes.

Pregnant and breastfeeding females (Ranitidine passes into breast milk) do not use it without asking a health professional.

If you are allergic to acid reducers and ranitidine, do not use it.

Also, do not use ranitidine if:

  • You have trouble or pain swallowing food.
  • There is vomiting with blood or black or bloody stool ( See your doctor as these may be an indication of a severe health issue)
  • If you have kidney disease, liver disease, lung disease, immune system problems and other stomach issues (Except under supervision of your doctor).

*Do not take the tablet if individual foil packet or individual blister unit or if the printed foil under the cap of the bottle is torn or open.


Drug interaction changes how medicines works and may increase the risk of serious side effects. This is why if you are on certain medications (prescription, non-prescription drug or even herbal products) share it with health professional or pharmacist.

Ranitidine reduces stomach acid, and so it may affect the work of products such as dasatinib, delavirdine, atazanavir, certain azole antifungals and pazopanib.

Never take Zantac with other acid reducers.

Side Effects Of Zantac

Many people taking ranitidine do not have serious side effects.

However, side effects such as constipation, diarrhoea and headache may occur, but if any of these side effects persist or gets worse, see your colour immediately.

Talk to a health professional right away, if you experience severe side effects such as:

  • Mood changes – depression, confusion, agitation or hallucinations)
  • Blurred vision
  • Easy bruising or bleeding
  • Severe tiredness
  • Enlarged breasts
  • Irregular, slow or fast heartbeat
  • Signs of infection – sore throat, fever and chills
  • Severe pain in the abdomen
  • Yellow skin and eyes
  • dark urine

*Elderly may be more sensitive to the side effects of ranitidine.

Serious reaction to ranitidine is uncommon, but get a medical emergency if you experience symptoms of a severe allergic reaction such as:

  • Itching/swelling
  • Rash
  • Severe dizziness
  • Shortness of breath
  • Trouble in breathing

* There may be other possible side effects that are not listed.

Ranitidine may interfere with specific lab tests such as urine protein tests and may cause false test results so make sure to let your doctor and laboratory personnel know if you are taking Zantac

What to Do If You Overdose

In the case of overdose, seek emergency medical. The symptoms of overdose include feeling light-headed, lack of coordination and fainting.

What If You Miss a Dose

Take the missed dose as soon as you remember. If it is the time of the next scheduled dose, do not take extra medicine to make up for the missed dose.


Store the medicine at 20-25 degrees Celsius away from excessive humidity or heat.

*To make the medicine work better, make changes in your diet and lifestyle such as avoiding too much spicy food, caffeine, eating small meals at small intervals, practising regular exercising etc. Talk to your dietician and doctor about lifestyle and diet changes you need to make.

Better, avoid alcohol if you are taking ranitidine as it increases the risk of damage to the stomach.

Disclaimer: The information displayed in this article is only for knowledge purpose. Avoid self-medication. Consult healthcare provider before taking any drug or discontinuing any course of any treatment.