OMEPRAZOLE
( Prilosec OTC™ [OTC]; Prilosec®)

DOSING: ADULTS

Active duodenal ulcer: 20 mg/day for 4-8 weeks
Gastric ulcers: 40 mg/day for 4-8 weeks
Symptomatic GERD: 20 mg/day for up to 4 weeks
Erosive esophagitis: 20 mg/day for 4-8 weeks; maintenance of healing: 20 mg/day for up to 12 months total therapy
Peptic ulcer disease: Eradication of Helicobacter pylori: Dose varies with regimen: 20 mg once daily or 40 mg/day as single dose or in 2 divided doses; requires combination therapy with antibiotics
Frequent heartburn (OTC labeling): Oral: 20 mg/day for 14 days; treatment may be repeated after 4 months if needed

DOSING IN RENAL IMPAIRMENT — No adjustment is necessary.

DOSING IN HEPATIC IMPAIRMENT Specific guidelines are not available; bioavailability is increased with chronic liver disease.


ADMINISTRATION

Capsule: Should be swallowed whole; do not chew or crush. Best if taken before breakfast. Delayed release capsule may be opened and contents added to applesauce.
Tablet: Should be swallowed whole; do not crush or chew.


SIGNIFICANT  ADVERSE REACTIONS
 Abdominal pain
 Cough
 Dizziness
 Headache
 Rash
 Diarrhea
 Nausea / Vomiting  
Constipation
 Taste perversion


CONTRAINDICATIONS 

Hypersensitivity to omeprazole or  substituted benzimidazoles (ie, esomeprazole,


DRUG INTERACTIONS 

Antifungal agents (imidazole): Proton pump inhibitors may decrease the absorption of itraconazole , ketoconazole,indinavir ,  atazanavir and  the serum concentration of nelfinavir.
Esomeprazole and omeprazole may increase levels of benzodiazepines metabolized by oxidation –such as , diazepam, midazolam, triazolam
Clozapine: Omeprazole may alter the concentrations/effects of clozapine
CYP2C9 substrates: Omeprazole may increase the levels/effects of CYP2C9 substrates. Example substrates include bosentan, dapsone, fluoxetine, glimepiride, glipizide, losartan, montelukast, nateglinide, paclitaxel, phenytoin, warfarin, and zafirlukast.
CYP2C19 inducers: May decrease the levels/effects of omeprazole. Example inducers include aminoglutethimide, carbamazepine, phenytoin, and rifampin.
CYP2C19 substrates: Omeprazole may increase the levels/effects of CYP2C19 substrates. Example substrates include citalopram, diazepam, methsuximide, phenytoin, propranolol, and sertraline.
HMG-CoA reductase inhibitors: Omeprazole may increase the levels/effects of HMG-CoA reductase inhibitors; monitor..
Iron salts (oral): Omeprazole may decrease the absorption of oral iron salts
Methotrexate: Concurrent use with omeprazole may decrease the excretion of methotrexate.
Phenytoin: Elimination of phenytoin may be prolonged; monitor. Phenytoin may decrease omeprazole levels/effects.
Warfarin: Proton pump inhibitors may increase the levels/effects or warfarin; monitor.

PREGNANCY RISK FACTOR — C

LACTATION — Enters breast milk/not recommended