H2 Receptor Antagonists and Acid Reflux

By Patricia Raymond, Michelle Beaver

H2 receptor antagonists (also known as H2 blockers) are prescribed to treat occasional acid reflux that results from too much stomach acid making its way up the esophagus and causing esophageal inflammation.

These drugs used to be prescription only, but they’ve recently been approved for over-the-counter sales. The only difference between the over-the-counter and prescription forms of the drug is dosage.

It’s common for an H2 receptor antagonist to be prescribed alongside other medications as part of a reflux or GERD treatment plan. Many doctors recommend using H2 receptor antagonists to help reduce the severity and frequency of acid reflux attacks, while using antacids to help alleviate the immediate symptoms associated with heartburn and reflux.

Your doctor may recommend taking antacids and H2 receptor antagonists together to prevent your reflux, but don’t take them within one hour of each other. Taking antacids within the same hour can make the H2 blocker take longer to work.

How they work

H2 receptor antagonists target one of the critical components in acid reflux, stomach acid. Unlike antacids, which reduce or neutralize already existing stomach acid, H2 receptor antagonists block or prevent the production of new stomach acid. They reduce stomach acid production by blocking histamine receptors in stomach cells.

Histamine is a neurotransmitter common in the body. In the stomach, histamine is one of the triggers for acid production. H2 blockers reduce the acidity level of the stomach, so even if the stomach’s contents enter the esophagus, there is less esophageal damage and inflammation.

This type of drug can be given in one of two ways: by mouth or injection through an intravenous (IV) line. The injection version is used solely in the hospital. Generally, H2 receptor antagonists are taken orally once or twice daily. Some patients find that they only need to take the medication once a day, shortly after dinner but before bedtime.

Like other medications, your specific dose and treatment regime will be determined by your doctor, based on your symptoms as well as your reaction to the medication.

Histamine receptors are most active in the evenings, so you get more bang for your buck taking your H2 receptor antagonists toward the end of the day. Discuss the best timing with your doctor or pharmacist.

What they’re good for

H2 receptor antagonists are inexpensive and can be very helpful in treating mild to moderate cases of acid reflux. Clinical trials have shown that people who only have symptoms a couple times a month respond well to this type of medication. Studies have found that around half of all GERD patients respond favorably to treatment with H2 receptor antagonists.

This type of drug can be very helpful in reducing the number and severity of symptoms associated with acid reflux. Although H2 blockers rarely eliminate every symptom, they can have a dramatic impact on your day-to-day well-being. They’re most helpful when you’re anticipating reflux.

If you know you’re going to be having a few drinks or going out to an especially spicy meal, this particular type of drug can be a great tool. Taking an H2 receptor antagonist about an hour before you go out can significantly reduce the risk of suffering an excruciating bout of heartburn or other acid reflux symptoms. However, this “as needed” dosage should be an occasional thing — don’t abuse it.

Another benefit of H2 receptor antagonists is the impact they have on the esophagus. Several studies have shown that these types of drugs can help heal the damage that acid reflux does to the esophagus. Although the drug itself has been shown to speed esophageal healing, there’s also the fact that these types of drugs provide longer-term relief than antacids.

H2 blockers help prevent reflux flare-ups instead of simply neutralizing them as they manifest. This means fewer flares and more time for the esophagus to heal before it’s exposed to corrosive stomach acid again.

What they’re not so good for

Although H2 receptor antagonists can be great for about half of GERD patients, others still have breakthrough symptoms of reflux despite taking them.

H2 blockers usually provide longer relief than antacids, but they also take longer to work. While antacids can provide near immediate relief from heartburn and other reflux symptoms, H2 receptor antagonists usually take at least an hour to provide any relief. This type of medication isn’t ideal for immediate flare-ups, but it’s often effective for long-term acid reflux reduction and relief.

H2 blockers do provide relief for a longer period of time than antacids, but they’re still a short-term fix for your reflux. They only affect stomach acid production for a short period, meaning that your body will return to its usual acid production after you stop taking the medication.

Potential side effects

Pay attention to both the frequency and severity of any side effects. Also make sure to tell your doctor about any changes to side effects that you notice. Good news: Just because you experience a side effect when you start taking a specific medication doesn’t mean that you’ll always have to deal with that side effect.

It’s common for some side effects, especially mild ones, to go away after a patient has been on a particular medication for a few weeks or even a few days.

Just like any of the other over-the-counter reflux medications, you shouldn’t take H2 receptor antagonists for more than two weeks without getting the green light from your doctor. You should be aware of a variety of side effects associated with H2 blockers. For instance, constipation and diarrhea have been reported. Dizziness, headaches, nausea, and vomiting are other side effects that have been associated with H2 receptor antagonists.