Is Cimetidine Available OTC? Pharmacist-Backed Answers to 9 Cimetidine FAQs

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You just finished dining at your favorite restaurant. But you're quickly learning that the meal isn't agreeing with your system. You're experiencing burning in your chest - a classic heartburn symptom. This is a scenario that plays out for many people.

Many over-the-counter (OTC) remedies are available for moments like these. Cimetidine (Tagamet HB) is one of them. But how does it work? Knowing the answer to this question and others about cimetidine can help you decide whether it's the right choice for you or a loved one.

1. Can you buy cimetidine over the counter?

Yes. Cimetidine is commonly found OTC at a variety of locations, such as your local pharmacy or supermarket. It's also widely available online. But you should only take OTC cimetidine if you're at least 12 years old and need it to treat or prevent heartburn.

If you have another condition - such as a gastric (stomach) ulcer - it's better to get a prescription for cimetidine from your healthcare professional. A higher, prescription-only dose of the medication is more effective for these conditions.

Good to know: If you've been taking OTC cimetidine for longer than 14 days (2 weeks), it's a good idea to reach out to your prescriber about your symptoms. They can determine if you need a different medication or dose for better results.

2. What is cimetidine used for?

Cimetidine is FDA-approved to treat a variety of stomach-related health conditions - not just heartburn. It's available with a prescription for adults and teens ages 16 and older for:

• Gastroesophageal reflux disease (GERD) with tissue damage

• Active gastric ulcers

• Active duodenal (small intestine) ulcers

• Duodenal ulcer maintenance

• Zollinger-Ellison syndrome and other conditions that produce excess stomach acid

3. What's a common cimetidine dosage?

Recommended cimetidine dosages depend on different factors, most notably the condition you're taking it for. Whether you're taking OTC or prescription cimetidine also influences your dosage.

OTC cimetidine dosage

OTC cimetidine comes as 200 mg tablets. The recommended cimetidine dosage for heartburn prevention is 1 tablet by mouth about 30 minutes before eating or drinking something that triggers your symptoms. To treat heartburn, take 1 tablet (200 mg) by mouth when your symptoms begin.

You shouldn't take more than 2 tablets (400 mg) in 24 hours.

Prescription cimetidine dosages

Prescription-strength cimetidine comes as 200 mg tablets, too. But it's also available as 300 mg, 400 mg, and 800 mg tablets.

You have some flexibility with how you take prescription cimetidine. You can take either one large dose at bedtime or smaller doses throughout the day. The choice is yours, depending on your daily schedule or other medications you might be taking.

Here's a summary of prescription cimetidine dosages, broken down by health condition.

Cimetidine dosage for kidney problems

Medications can sometimes build up in your body if you have kidney problems. In these situations, your kidneys have trouble removing the medication(s) from your body. You may need a lower medication dose in turn.

The recommended cimetidine dosage for people with kidney problems is 300 mg by mouth every 12 hours. This dosage applies to all conditions from the table above.

4. Is cimetidine used for warts in children?

Yes, it can be. While cimetidine isn't approved to treat warts in children, it's been studied for this purpose. This is known as an off-label use.

Warts are common in children, and having a weakened immune system can raise the risk of having them. It's thought that cimetidine helps the immune system fight off warts.

The cimetidine for warts child dosage is based on body weight. A possible cimetidine dosage for warts is 30 mg to 40 mg per kg body weight per day for up to 6 months.

If your child has warts, reach out to their pediatrician for treatment recommendations.

5. How long can you take cimetidine?

There's not a set duration for cimetidine use. It depends on why you're taking cimetidine. Here's a quick overview.

6. What should I do if I miss a dose of cimetidine?

If you miss a dose of cimetidine, take it as soon as you remember it. But if it's almost time for your next dose, skip the missed one. You can go back to your normal cimetidine schedule when the next one rolls around.

However, if you forget to take your dose of OTC cimetidine before having a food or drink that typically causes heartburn symptoms, not to worry. You can take it if you start to experience symptoms. Just remember not to take more than 2 tablets in 24 hours.

If you find you're missing cimetidine doses frequently, a variety of tools can help you stay on track. Medication reminder apps and pillboxes are a couple of examples. If you have the GoodRx app on your smartphone, the Medicine Cabinet feature is another option to try.

7. How does cimetidine work?

Cimetidine is a histamine-2 antagonist, better known as an H2 blocker. It works by blocking histamine receptors (chemical binding sites) in your stomach. Histamine is a chemical that tells your brain to release more stomach acid.

By blocking these receptors, cimetidine lowers stomach acid levels. This often leads to symptom improvement.

8. Is cimetidine safe?

Yes. Cimetidine is safe to take overall. But as with any medication, there are side effects you should be aware of before starting it. Headache, diarrhea, and dizziness are all common cimetidine side effects.

Gynecomastia (breast enlargement in men) has also been reported. This is more likely to happen in people taking cimetidine for 1 month or more. Symptoms should gradually get better or go away after stopping cimetidine.

While rare, cimetidine may cause more serious side effects, too, such as confusion and pneumonia. Reach out to your prescriber if you experience any serious side effects or bothersome symptoms that won't go away.

Good to know: Cimetidine and other H2 blockers have a lower risk of long-term side effects than another group of acid reducers - proton pump inhibitors (PPIs). Omeprazole (Prilosec) and pantoprazole (Protonix) are common PPIs. But research shows that PPIs are generally more effective than H2 blockers.

9. Why does cimetidine cause drug interactions?

Cimetidine causes drug interactions because it's known to block cytochrome P450 (CYP450) enzymes. These enzymes have an important job; they help break down (metabolize) medications in your body.

By blocking certain CYP enzymes, cimetidine can cause other medications to accumulate in the body. This worsens the odds of experiencing new or worsening side effects from the affected medication.

Here are examples of cimetidine interactions:

• Warfarin (Coumadin, Jantoven)

• Phenytoin (Dilantin, Phenytek)

• Propranolol (Inderal LA, InnoPran XL)

• Diltiazem (Cardizem)

• Amitriptyline

Managing cimetidine interactions

Cimetidine's interactions are typically manageable. Your prescriber and pharmacist will walk you through what to do if you're affected by one. For instance, they may recommend taking a different H2 blocker - such as famotidine (Pepcid AC) - that's less likely to interact.

Medications that need stomach acid to be absorbed can also be affected by cimetidine. Since cimetidine is an acid reducer, it can lower the absorption of these medications. Ketoconazole is one example of a medication that may be less effective when combined with cimetidine. To help prevent this interaction, you can take your ketoconazole doses with an acidic drink, such as non-diet soda.

Keep in mind: Other medications may interact with cimetidine, too. That's why it's a good idea to keep a current medication list handy for your prescriber and pharmacist. They can check if any of your medications interact with cimetidine.

How to save on cimetidine

There are ways to save on cimetidine, which is available as both brand-name and generic medications.

GoodRx can help you save over 70% off the average retail price of the generic, prescription version. Generic cimetidine's price at certain pharmacies is as low as $25.23for 60 tablets with a free GoodRx discount.

You can save on OTC medications using GoodRx, too. If your healthcare professional writes you a prescription for OTC cimetidine, you can apply a GoodRx discount to it. Just search for cimetidine HB on GoodRx, make sure the 200 mg dose is selected, and input your desired medication quantity.

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