In 2020, drugmakers removed all forms of prescription and over-the-counter (OTC) ranitidine (Zantac) from the U.S. market at the request of the FDA. This is because NDMA (a cancer-causing chemical) found in some ranitidine products is a probable carcinogen.

Since then, Zantac, now named Zantac 360, was converted into a different product. Although Zantac 360 is a new product, its generic name, famotidine, is familiar. It is also known as Pepcid AC. Both ranitidine and famotidine work the same way, so changing the new Zantac 360 to famotidine was the closest switch possible.

Prilosec OTC and Zantac 360 are medications used to treat stomach problems, such as heartburn and sour stomach. They both work by reducing acid in the stomach, but Prilosec OTC and Zantac 360 do this differently.

Prilosec OTC and Zantac 360 are available in prescription and over-the-counter (OTC) forms. This article covers the OTC versions. Read on to learn more about how Prilosec OTC and Zantac 360 are similar and different. This information can help you decide which drug may be better.

Prilosec OTC is a brand name for the generic drug omeprazole. It works by binding up pumps in your stomach so that they cannot produce acid. Zantac 360 is a brand name for a different drug, famotidine. Zantac 360 blocks a chemical found in your body called histamine that activates stomach acid pumps.

Because Prilosec OTC builds up in your system, it lasts longer and is more potent than Zantac 360. However, Zantac 360 works more quickly than Prilosec OTC because it does not have to build up in your system to work.

Prilosec OTC and Zantac 360 come in tablets or capsules you take by mouth. The typical length of over-the-counter use is 14-days. These drugs treat similar conditions, including:

  • heartburn
  • stomach upset

The OTC package recommends discussing with a healthcare professional if you need to use them beyond 14-days.

You may take these medications by prescription for the following conditions:

In addition, Prilosec can also treat H. pylori infection and Barrett’s esophagus.

The FDA has not approved Prilosec OTC for self-treatment in children younger than 18-years. And for Zantac 360, self-treatment is not recommended in children younger than 12-years. Therefore, these drugs should only be used in children of these ages if recommended or prescribed by a doctor.

Prilosec OTC is a once-a-day medication with lasting acid reduction for up to 24-hours. However, it works better when you take it on an empty stomach 30- to 60-minutes before a meal. Also, it takes 1–4 days for Prilosec OTC to give you complete relief.

Zantac 360 prevents heartburn right away when you take it 15-minutes before a meal, and it lasts approximately 12-hours. Also, it works best when you take it twice daily.

Both medications are available in generic forms. The generic versions tend to be cheaper than the brand-name versions. For information on current prices for Prilosec and Zantac, visit

Like most medications, Prilosec OTC and Zantac 360 can cause side effects. Their common side effects are similar and can include:

  • headache
  • diarrhea
  • stomach pain
  • nausea
  • vomiting
  • gas
  • constipation
  • dizziness
  • drowsiness

Yet, these medications can cause more serious side effects differing from each other. This may happen because they work in unrelated ways.

Serious side effects of Prilosec OTC can include:

  • liver problems
  • upper respiratory infections, with symptoms such as congestion, sore throat, or cough
  • long-lasting inflammation of the stomach lining
  • low blood magnesium and vitamin B-12 levels
  • gut infection with Clostridioides difficile (formerly Clostridium difficile), causing severe diarrhea
  • bone fractures

Serious side effects of Zantac 360 can include:

Although these drugs treat the same problems, they’re different in how they work and break down in your body. As a result, they can interact with other medications. The sections below have examples of drugs that may interact, but this is not a complete list.

Prilosec OTC and Zantac 360 both reduce stomach acid; so, they can decrease the absorption and lower the action of these medications in the following diseases:

  • iron for anemia
  • dasatinib, erlotinib, nilotinib for cancer
  • itraconazole, ketoconazole for fungal infections
  • ledipasvir/sofosbuvir for hepatitis
  • atazanavir, nelfinavir, rilpivirine, delavirdine for HIV
  • amoxicillin, ampicillin for bacterial infections

Besides lowering the efficacy of certain medications by reducing stomach acid, Zantac 360 has very few drug interactions. This is an advantage of its use over Prilosec OTC. However, it can increase the blood levels of the muscle relaxer tizanidine, causing blood pressure to drop too low.

Prilosec OTC has several effects on your liver’s ability to remove medicines from the body, limiting its use.

Prilosec OTC increases the action of these medicines, resulting in the listed problems:

  • saquinavir for HIV–rash with blisters, liver problems, flu-like symptoms
  • digoxin for heart failure–nausea, vomiting, abnormal vision
  • methotrexate for cancer–blood, liver, and kidney problems
  • diazepam, midazolam, triazolam for muscle relaxation–excessive sleep, hard to awaken
  • warfarin for blood thinning–bleeding that is hard to stop
  • phenytoin for seizures–falls, clumsy movement, hard to awaken
  • cyclosporine, tacrolimus for organ transplants–low blood magnesium, damage to heart, kidney, or liver
  • citalopram for depression–irregular heartbeat, sudden heart attack
  • cilostazol for blood circulation–blood too thin, irregular heartbeat
  • glipizide for blood sugar–blood sugar too low

Prilosec OTC decreases the action of the following drugs and causes the related issues:

  • clopidogrel for blood thinning–blood clots that can lead to heart attack and stroke
  • clozapine for schizophrenia–worsening of mental health

Other drugs can decrease the ability of Prilosec OTC to reduce acid, including:

  • voriconazole for fungus
  • St. John’s wort for depression
  • rifampin for bacterial infection

When you are unsure about drug interactions, check with your pharmacist, who can conduct a computer screening.

Overall, your health is a factor in deciding if a drug is a good choice. Therefore, always consider your health conditions before using any medication.

Use with other medical conditions

While Prilosec OTC and Zantac 360 are relatively safe, they may cause problems if you have certain health conditions.

Talk to your doctor before using Prilosec OTC if you have:

  • liver disease
  • osteoporosis
  • history of Clostridioides difficile diarrhea

Talk to your doctor before using Zantac 360 because doses will need lowering if you have:

  • low kidney function
  • advanced age

Use during pregnancy and breastfeeding

Both Prilosec OTC and Zantac 360 are likely safe to use during pregnancy and while breastfeeding. Zantac 360 may be a first choice since it has a short duration of action, but Prilosec OTC may be needed based on the condition. However, always talk to the doctor before using any drugs while pregnant or breastfeeding.

Prilosec OTC and Zantac 360 are similar in many ways. However, some of their key differences may include:

  • Prilosec OTC takes longer to work and has longer-lasting and stronger action with once-daily dosing, but it has more drug interactions and long-term side effects.
  • Zantac 360 works more quickly but is not as strong and does not last as long, only up to 12-hours. Zantac 360 does not affect the liver and has few drug interactions, yet doses need lowering in advanced age and reduced kidney function.

If you have chest or shoulder pain symptoms along with heart palpitations, dizziness, or shortness of breath, do not take Prilosec OTC or Zantac 360. Instead, seek immediate medical care, as these could be heart attack symptoms.

More questions? Talk to your doctor or pharmacist about Prilosec OTC or Zantac 360, and they can answer questions and help you decide if one of these drugs is a suitable choice to use.

Author Note: If you still have recalled ranitidine products, please take them to a drug take-back site or dispose of them according to the FDA’s guidance.