According to the National Institutes of Health, Prilosec is a proton pump inhibitor 1. Also known as or omeprazole, Prilosec is mainly used in infants to treat gastroesophageal reflux disease, a condition in which backward flow of acid from the stomach causes heartburn and injury of the esophagus. Infants with GERD are at a high risk of aspiration pneumonia and asthma caused by acidic stomach contents entering the lungs. Prilosec is prescribed in such infants to prevent reflux. Some infants may suffer from side effects.

Gastrointestinal Effects

According to Drugs.com, use of Prilosec in infants may cause common side effects such as diarrhea, constipation, upset stomach and flatulence 2. Long-term use of Prilosec may cause:

• inflammation of the pancreas
  
• irritable colon
  
• stool discoloration
  
• growth of fungus in the esophagus
  
• stomatitis
  
• abdominal swelling
  
• mucosal atrophy of the tongue

Prilosec suppresses stomach acid, which is important for killing bacteria, fungi and parasites. Long-term blocking of stomach acid also hinders the absorption of vitamins and minerals needed for healthy growth.

Hematologic Effects

Drugs.com states that use of Prilosec in infants may cause agranulocytosis, which is the failure of the bone marrow to make enough white blood cells 2. Lack of white blood cells may lead to infections in infants. Prilosec may also cause low production of red blood cells and platelets, leading to anemia and abnormal bleeding.

Hypersensitivity

According to Drugs.com, some infants may be allergic to Prilosec and develop severe allergic reactions from taking Prilosec 2. Signs of allergic reactions include:

• chest tightness
  
• closing of the throat
  
• swelling of the throat
  
• problems breathing
  
• shortness of breath
  
• difficulties breathing
  
• rashes
  
• hives
  
• itching

Nervous System Effects

According to Drugs.om, use of Prilosec in infants may cause the infants to be irritable and inconsolable 2. The infants may also refuse to sleep.