H2 Blockers

Scleroderma is a rare disease associated with excessive production of collagen, a major component of scar tissue, causing characteristic patches of tight and hard skin. Several types of scleroderma exist, broadly categorized into one of two groups: localized scleroderma, which usually only affects the skin, and systemic scleroderma, which as its name implies is multi-system.  

Systemic scleroderma typically affects both the skin and internal organs, such as the heart, lung, kidneys and the digestive tract. One common issue is gastroesophageal reflux disease  (GERD), where the muscle sealing the junction between the stomach and food pipe (or esophagus) weakens.  

GERD is associated with frequent heartburn, as stomach acid travels back up the esophagus. This results in discomfort as the esophagus becomes inflamed, and can cause permanent damage if left untreated. 

Several treatments are available to reduce GERD symptoms and prevent permanent damage from occurring. Histamine H2-receptor antagonists or H2 blockers are one such treatment. 

How H2 blockers work

Stomach acid is secreted by cells lining the wall of the stomach. When a substance called histamine binds to a receptor on these cells, for example in response to eating, this triggers the cell to start releasing stomach acid. In a patient with GERD, this stomach acid can escape the stomach and travel up the esophagus. 

H2 blockers reduce the symptoms of GERD by reducing the amount of stomach acid produced. They compete with histamine to bind to the receptors, blocking the cells from being stimulated. 

With less stomach acid being produced, the likelihood of acid backing up into the esophagus is reduced. This should reduce discomfort, and allow time for the esophagus to heal. 

Types of H2 blockers 

There are many types of H2 blockers, which can be taken by mouth or administered as an injection into the bloodstream. Some are available over-the-counter at reduced doses, but stronger prescription medications are often recommended for chronic GERD.  

Examples of common H2 blockers include Axid (nizatidine), Pepcid (famotidine), Tagamet (cimetidine), and Zantac (ranitidine). 

Other information 

In rare cases, H2 blockers may cause side effects such as constipation or diarrhea, difficult urination, drowsiness, dry mouth or skin, and headaches. In elderly patients, H2 blockers may also cause dizziness and confusion. 

Long-term use of H2 blockers may be associated with vitamin B-12 deficiency and an increased risk of bone fractures. 

H2 blockers may be prescribed in addition to other medications, such as proton pump inhibitors (PPIs) that reduce stomach acid through a later stage in the same pathway, working prevent GERD symptoms from resurfacing at night. 


Scleroderma News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.