omeprazole (Rx, OTC)
Hypersensitivity to omeprazole or other proton pump inhibitors (PPIs)
PPIs are possibly associated with increased incidence of Clostridium difficile-associated diarrhea (CDAD); consider diagnosis of CDAD for patients taking PPIs who have diarrhea that does not improve
May require dosage reduction with liver disease
Cutaneous lupus erythematosus (CLE) and systemic lupus erythematosus (SLE) reported with PPIs; avoid using for longer than medically indicated; discontinue if signs or symptoms consistent with CLE or SLE are observed and refer patient to specialist
Shown to cause gastric carcinoid tumors in rats with increased doses, but risk in humans unconfirmed
Published observational studies suggest that PPI therapy may be associated with an increased risk for osteoporosis-related fractures of the hip, wrist, or spine, particularly with prolonged ( 1 yr), high-dose therapy
Hypomagnesemia may occur with prolonged use ( 1 year); adverse effects may result and include tetany, arrhythmias, and seizures; in 25% of cases reviewed, magnesium supplementation alone did not improve low serum magnesium levels and the PPI had to be discontinued
Decreased gastric acidity increases serum chromogranin A (CgA) levels and may cause false-positive diagnostic results for neuroendocrine tumors; temporarily discontinue PPIs before assessing CgA levels
Inhibits hepatic isoenzyme CYP2C19 and may alter metabolism of drugs that are CYP2C19 substrates
PPIs may decrease the efficacy of clopidogrel by reducing the formation of the active metabolite
Daily long-term use (e.g. longer than 3 years) may lead to malabsorption or a deficiency of cyanocobalamin
Acute interstitial nephritis has been observed in patients taking PPIs
Relief of symptoms does not eliminate the possibility of a gastric malignancy
Therapy increases risk of Salmonella, Campylobacter, and other infections
May elevate and/or prolong serum concentrations of methotrexate and/or its metabolite when administered oncomitantly with PPIs, possibly leading to toxicity; consider a temporary withdrawal of PPI therapy therapy with high dose methotrexate administration
Pregnancy category: C
Lactation: Distributes into human breast milk; use caution
Breast milk peak concentration time
3 hr following 20 mg dose (peak concentration 7% of peak serum concentrations)
Because of the potential for serious adverse reactions in nursing infants from omeprazole, and the potential for tumorigenicity shown in rat carcinogenicity studies, a decision should be made to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Drugs that require prior authorization. This restriction requires that specific clinical criteria be met prior to the approval of the prescription.
Drugs that have quantity limits associated with each prescription. This restriction typically limits the quantity of the drug that will be covered.
Drugs that have step therapy associated with each prescription. This restriction typically requires that certain criteria be met prior to approval for the prescription.
Drugs that have restrictions other than prior authorization, quantity limits, and step therapy associated with each prescription.