Before Using This Medicine

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For omeprazole, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to omeprazole. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy—Studies have not been done in humans. However, studies in animals have shown that omeprazole may cause harm to the fetus.

Breast-feeding—Omeprazole may pass into the breast milk. Since this medicine has been shown to cause unwanted effects, such as tumors and cancer in animals, it may be necessary for you to take another medicine or to stop breast-feeding during treatment. Be sure you have discussed the risks and benefits of the medicine with your doctor.

Children—There is no specific information comparing the use of omeprazole in children with use in other age groups.

Older adults—Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of omeprazole in the elderly with use in other age groups.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking omeprazole, it is especially important that your health care professional know if you are taking any of the following:

• Anticoagulants (blood thinners) or
• Diazepam (e.g., Valium) or
• Phenytoin (e.g., Dilantin)—Use with omeprazole may cause high blood levels of these medicines, which may increase the chance of side effects

Other medical problems—The presence of other medical problems may affect the use of omeprazole. Make sure you tell your doctor if you have any other medical problems, especially:

• Liver disease or a history of liver disease—This condition may cause omeprazole to build up in the body