Ranitidine is a best-selling drug used to reduce high stomach acid. Through its lowering effect on stomach acid, it is widely used in the treatment of conditions such as gastroesophageal reflux, ulcers in the stomach and bowel, erosive esophagitis, and Zollinger-Ellison syndrome. Read on to learn more about this medication, its health benefits, and main adverse effects.
Disclaimer: By writing this post, we are not recommending this drug. Some of our readers who were already taking the drug requested that we commission a post on it, and we are simply providing information that is available in the scientific literature. Please discuss your medications with your doctor.
Ranitidine is a drug that decreases stomach acid production and is therefore employed in the treatment and prevention of disorders related to excessive stomach acid .
Developed in 1977, ranitidine was first introduced into the market in 1981 and quickly became the best-selling drug worldwide .
The main brand names for ranitidine are Zantac® and Taladine®.
Prescription ranitidine comes as tablets (oral and effervescent), capsules, and syrup. This medication is mainly used to treat :
- Ulcers of the stomach and bowel
- Esophagus inflammation
- Gastroesophageal reflux disease (GERD)
- Zollinger-Ellison syndrome
- Acid indigestion
Histamine is a compound that is produced by white blood cells (mast cells and basophils), platelets, immune cells (lymphocytes), brain cells, and secreting cells in stomach glands (enterochromaffin cells) .
In the stomach, histamine is produced by enterochromaffin cells and activates those that produce acid (parietal cells) by binding to the H2-receptors on their surface .
Ranitidine and other H2-receptor blockers were designed by using histamine as a starting point and modifying its chemical structure .
These chemicals compete with histamine for binding to the H2-receptor. The reversible interaction between a blocker and the receptor prevents the binding of histamine, and thus the activation of acid production .
Over-the-counter ranitidine is approved to prevent and relieve heartburn associated with acid ingestion and sour stomach. Prescription ranitidine is mainly approved for the treatment and prevention of ulcers of the stomach and intestines and gastroesophageal reflux disease.
Follow your doctor’s instructions carefully. Take ranitidine as recommended and do not change its dose and frequency or stop taking it without your doctor’s approval. Your healthcare provider may recommend you combine ranitidine with other medications (such as antacids and PPIs). Talk to your doctor if your condition doesn’t improve or if it worsens.
Gastroesophageal reflux disease (GERD) is the abnormal entry of stomach acid into the esophagus. The main symptoms of this disease, which affects 20% of the US adult population at least once a week, are heartburn and regurgitation .
Low doses of ranitidine decreased stomach acid for 9 hours in a small trial on 24 healthy people .
However, a small trial on 18 people with GERD showed the development of tolerance to the medication after long-term treatment with ranitidine, resulting in a reduced efficiency .
In a small trial on 29 children, low doses of ranitidine reduced stomach acid .
In a small trial on 18 pregnant women, ranitidine twice daily relieved GERD symptoms more efficiently than the same dose once daily .
However, PPIs generally outperform ranitidine in the treatment of this disease.
Both ranitidine and omeprazole were equally efficient in treating GERD symptoms in a clinical trial on 76 children .
Heartburn is a burning and painful sensation in the chest and upper stomach that is normally due to the entry of stomach acid into the esophagus, and is the main symptom of gastroesophageal reflux disease (GERD) .
Heartburn is generally well controlled with antacids. While H2-receptor blockers and PPIs prevent the formation of acid in the stomach, antacids neutralize it after its production .
In a clinical trial on almost 100 people with self-perceived heartburn taking either an antacid (Maalox) or ranitidine, the antacid was faster in relieving heartburn symptoms .
In a small trial on 26 people with frequent meal-induced heartburn, ranitidine was faster at reducing stomach acidity, while the effect of the antacid (calcium carbonate) was faster in the esophagus .
In a longer-term trial on over 150 people suffering from heartburn frequently, ranitidine was more effective than antacid (calcium carbonate) in relieving heartburn, curing erosive esophagitis, reducing pain, and improving life quality .
However, doubling the dose to 300 mg did not improve the recovery rate in the first trial .
A small proportion of people with gastroesophageal reflux disease (GERD) develop erosive esophagitis, in which the lining of the esophagus is inflamed and worn away .
Those whose esophagus is in contact with stomach acid for extended periods have the highest risk of developing erosive esophagitis .
In a small trial on 7 people with erosive esophagitis, low doses of ranitidine decreased the exposure of the esophagus to acid, but failed to reduce it to normal values .
In a trial on almost 400 people with erosive esophagitis being treated with proton pump inhibitors (PPIs), adding ranitidine improved heartburn symptoms in the short term, but patients eventually developed tolerance .
Zollinger-Ellison syndrome is the presence of a tumor, normally in the pancreas, bowel, or nodes on the stomach, which produces a hormone (gastrin) that stimulates the increased release of stomach acids .
The symptoms are caused by the excess of acid and include :
- Ulcers in the bowel
- Gastroesophageal reflux
- Loss of appetite
Excessive acid production can be treated with H2-receptor blockers. Due to its low side effects and limited interactions with other drugs, ranitidine is often the treatment of choice .
Ranitidine has also been effectively used in managing Zollinger-Ellison syndrome in pregnant women .
Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly prescribed to treat inflammatory conditions and reduce pain. Their long-term use is associated with increased risk of developing ulcers in the stomach and bowel [63, 64].
Given their stronger action, PPIs have been included in trials comparing their efficiency to that of ranitidine against NSAID-induced ulcers.
In a clinical trial of over 500 people on NSAID with ulcers in the stomach or bowel, omeprazole was more effective than ranitidine in healing and preventing ulcers .
The efficiency of esomeprazole in healing NSAID-induced stomach ulcers was higher in people taking esomeprazole than in those taking ranitidine in one trial on over 400 people, but comparable in a similar one [75, 76].
Critically ill patients, such as those in intensive care units, are more prone to stomach ulcers .
Because stress-induced ulcers are uncommon at low acid levels in the stomach, H2-receptor inhibitors are very popular for prevention of ulcers .
In a small trial on 37 people in intensive care units, ranitidine efficiently reduced stomach acidity, thus preventing the appearance of stress-induced ulcers .
In another trial on 48 newborn babies in the neonatal intensive care unit, short-term treatment with ranitidine prevented the appearance of stomach ulcers .
However, in a trial on almost 100 people in intensive care units with normal liver and kidney function subjected to long-term mechanical ventilation, ranitidine did not decrease the incidence rate of stress-induced ulcers .
In a meta-analysis of 3 studies, omeprazole was as effective as ranitidine in the prevention of stress-induced ulcers .
In contrast, sucralfate (a drug that binds to ulcers and creates a protective barrier against stomach acids) was at least as effective as ranitidine in preventing the appearance of stress-induced ulcers and reduced the risk of pneumonia in 2 trials [84, 85].
Ulcers are breaks in the lining of the stomach or first part of the small intestine.
The main symptoms are :
- Stomach pain
- Loss of appetite
- Vomiting of blood
- Weight loss
Helicobacter pylori is a bacteria that infects the digestive system. Although most infected individuals do not show symptoms of disease, infection with this bacteria is responsible for most ulcer cases diagnosed .
Ranitidine bismuth citrate, previously sold under the brand name Titrec® and now available as a generic drug, is an effective treatment against H. pylori-induced ulcers. This drug combines the acid-decreasing action of ranitidine and the antimicrobial and mucosal-protective roles of bismuth .
The combination of ranitidine bismuth citrate with the antibiotic clarithromycin was more effective in healing ulcers and eradicating H. pylori than ranitidine bismuth citrate alone in several studies [104, 105, 106, 107].
A clinical trial on over 200 people showed that amoxicillin could be used as an alternative to clarithromycin in those intolerant or resistant to this antibiotic .
In a trial on over 500 people with duodenal ulcer and H. pylori infection, a dual therapy with clarithromycin and omeprazole was as effective as one with this antibiotic and ranitidine bismuth citrate .
However, ranitidine bismuth citrate in triple therapy with amoxicillin and clarithromycin eradicated H. pylori more efficiently than all PPIs except rabeprazole in a trial on almost 400 people .
Acid aspiration is the inhalation of regurgitated stomach acids into the lungs. This complication may occur during surgical procedures .
Acid aspiration is particularly harmful to patients when the stomach is full and the acid level is high .
In a trial on almost 300 people about to undergo surgery, ranitidine twice per day reduced both stomach content volume and acid levels .
In another trial on 75 children, intake of water plus ranitidine prior to surgery reduced their risk of acid aspiration and improved their behavior .
The combination of ranitidine with pirenzepine reduced both stomach content volume and acidity in a clinical trial on over 100 children .
Because they prevent histamine activity, H2-receptor blockers like ranitidine may reduce the allergic response to some agents .
Henoch-Schönlein vasculitis is the inflammation of blood vessels caused by the allergic reaction to infections or drugs.
Its main symptoms include :
- Red- or purple-colored spots on the skin
- Stomach pain
- Stomach and bowel bleeding
- Blood in the urine
In a small trial on 12 people with Henoch-Schönlein vasculitis, treatment with ranitidine reduced the duration and severity of stomach pain and bleeding .
Gut bleeding is a condition in which blood vessels of the stomach, esophagus, or bowel are broken. It can be life-threatening if it affects large vessels .
Its most common causes are:
- Ulcers in the stomach and bowel 
- Mallory-Weiss tear 
- Stress-induced stomach inflammation 
- Dieulafoy lesions 
- Dilated veins in the stomach 
However, omeprazole was more effective than ranitidine in treating upper gut bleeding in a trial on almost 100 people .
In a multi-center trial on 1200 people requiring mechanical ventilation, ranitidine reduced gut bleeding more efficiently than sucralfate .
H2-receptor blockers may prevent 3 cancer-promoting effects of histamine:
- Increased activity of immune-suppressing cells 
- Prevention of tumor recognition by immune cells 
- Promotion of cancer cell growth 
In a trial on over 500 people with cancer in the large bowel who underwent tumor removal, treatment with ranitidine for 5 years improved survival in those who did not receive blood transfusions during the surgical procedure .
In cell trials, ranitidine reduced the growth and increased the death of colorectal cancer cells .
The two main types of IBD are :
The main symptoms common to both types of IBD are:
- Tablets: 75, 150, and 300 mg
- Capsules: 150 and 300 mg
- Syrup: 75 mg/5 ml
The most common over-the-counter doses to treat and prevent heartburn and acid indigestion are 75 and 150 mg per use per day .
Doubling the standard dose to 300 mg of ranitidine twice per day does not improve its efficiency in treating gastroesophageal reflux symptoms .
In people suffering from stomach and bowel ulcers, one single dose of 300 mg ranitidine daily is as effective as two doses of 150 mg per day .
In the treatment of erosive esophagitis, the recommended doses are ranitidine 300 mg twice daily or 150 mg per day 4 times daily .
Zollinger-Ellison syndrome can be treated with very high doses (up to 2.1 g ranitidine per day) .
Ranitidine is very safe and doses up to 6 g per day are generally well tolerated .
However, side effects have been reported. For more, check out this post.
The evidence for the effects of ranitidine on skin allergic reactions is based on a few studies of a relatively small size with a certain risk of bias .
More evidence is needed to evaluate the efficiency of ranitidine in colorectal cancer therapy .
Ranitidine, sold under the brand name Zantac®, is an H2 histamine receptor blocker that is prescribed to treat disorders caused by too much stomach acid production, such as gastric ulcers, GERD, heartburn, and erosive esophagitis.
It is also sometimes used to prevent acid aspiration during surgery and to help with allergic reactions and gut bleeding. Some early clinical evidence suggests that it may have a use in colorectal cancer therapy and to reduce bowel inflammation, but additional research is required.
Ranitidine is generally given in doses of between 75 and 300 mg per day, though higher doses are occasionally used. Make sure to follow your doctor’s instructions precisely if you are prescribed ranitidine.