Esomeprazole is a proton pump inhibitor that helps reduce the amount of gastric acid produced in the stomach. Esomeprazole achieves this by inhibiting an ion transport protein called H+/K+ ATPase that is present in the gastric parietal cells. The drug is cleared rapidly, with inactive metabolites such as 5-hydroxymethylesomeprazole and 5-carboxyesomeprazole mainly passed in the urine.
This drug is used in the short-term treatment of gastroesophageal reflux disease (GERD), to relieve inflammation and pain in the esophagus when patients are unable to take oral medications. It is also used in the treatment of peptic and duodenal ulcers and to reduce the risk of these ulcers bleeding after an endoscopy procedure. Other uses of this drug include in the prevention of gastric ulcers caused by non-steroidal anti-inflammatory drugs and treatment of the gastrointestinal ulcers associated with Chron’s disease.
The term “drug interaction” refers to the effects drugs have on each other when they interact in the body. Esomeprazole is a competitive inhibitor of CYP2C19 and CYP2C9, enzymes in the cytochrome P450 family that are important in the metabolism and excretion of other drugs. Inhibition of these enzymes by esomeprazole could therefore alter the efficacy of drugs that rely on these enzymes for their metabolism, such as diazepam (a sedative and anxiolytic) and warfarin (a blood thinner). If these drugs were used alongside esomeprazole, their concentration in the blood would rise and lead to drowsiness (caused by diazepam) and an increased tendency to bleed (caused by warfarin). On the other hand, drugs that rely on conversion by CYP2C19 and CYP2C9 to become activated (e.g clopidogrel) may have reduced effects on the body.
Furthermore, the absorption and efficacy of certain drugs depends on the presence of a certain amount of stomach acid. Since esomeprazole inhibits gastric acid, the effects of these drugs will be reduced and examples include ketoconazole and atazanavir.
Further examples of drugs that may interact with esomeprazole include the following:
- The anticoagulants cilostazol, methotrexate, digoxin, tacrolimus and saquinavir are examples of drugs where the risk of side effects may be increased by esomeprazole.
- The use of diuretics furosemide or hydrochlorothiazide may increase the risk of low magnesium levels when used in combination with esomeprazole.
- Voriconazole is an antifungal medication that may increase the likelihood of esomeprazole having side effects.
- St. John’s wort and ginkgo biloba are examples of drugs that may decrease the effectiveness of esomeprazole
Food can alter the absorption of esomeprazole and this drug should be taken at least an hour before eating any food so that absorption is not affected.
Interaction with medical conditions
Esomeprazole and the liver
Esomeprazole is mainly metabolized in the liver. No significant drug accumulation has been observed in patients with mild-to-moderate liver disease who take esomeprazole. However, significant plasma increases in esomeprazole have been observed among those with severe liver disease and a maximum daily dose of 20 mg is recommended for these patients.
Esomeprazole and the bones
Proton pump inhibitors have been shown to promote calcium loss from the bones as well as impairing the absorption of this mineral in the diet. In addition, research suggests that these drugs impair the absorption of magnesium, which is also required for bone mineralization. These side effects of esomeprazole mean the risk of osteoporosis is increased when taking this drug, particularly in women. People should inform their doctor if they have osteoporosis or risk factors for the condition, if esomeprazole is being considered as a treatment option.