Skip to Content
Here’s what to ask a doctor about hereditary angioedema

Omeprazole

Pronunciation

Pronunciation

(oh MEP ra zole)

Index Terms

  • Omeprazole Magnesium

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Capsule Delayed Release, Oral:

PriLOSEC: 10 mg, 20 mg, 40 mg

Generic: 10 mg, 20 mg, 40 mg

Capsule Delayed Release, Oral, as magnesium [strength expressed as base]:

Generic: 20 mg

Packet, Oral, as magnesium [strength expressed as base]:

PriLOSEC: 2.5 mg (30 ea); 10 mg (30 ea)

Suspension, Oral:

First-Omeprazole: 2 mg/mL (90 mL, 150 mL, 300 mL) [contains benzyl alcohol, fd&c red #40, saccharin sodium; strawberry flavor]

Omeprazole+Syrspend SF Alka: 2 mg/mL (120 mL, 240 mL)

Omeprazole+Syrspend SF Alka: 2 mg/mL (100 mL) [cherry flavor]

Tablet Delayed Release, Oral:

Generic: 20 mg

Tablet Delayed Release, Oral, as magnesium [strength expressed as base]:

PriLOSEC OTC: 20 mg

PriLOSEC OTC: 20 mg [contains fd&c blue #2 aluminum lake, fd&c red #40 aluminum lake, saccharin sodium]

PriLOSEC OTC: 20 mg [contains fd&c blue #2 aluminum lake, fd&c red #40 aluminum lake, saccharin sodium; wild berry flavor]

Brand Names: U.S.

  • First-Omeprazole
  • Omeprazole+Syrspend SF Alka
  • PriLOSEC
  • PriLOSEC OTC [OTC]

Pharmacologic Category

  • Proton Pump Inhibitor
  • Substituted Benzimidazole

Pharmacology

Proton pump inhibitor; suppresses gastric basal and stimulated acid secretion by inhibiting the parietal cell H+/K+ ATP pump

Absorption

Rapid

Metabolism

Hepatic via CYP2C19 primarily and (to a lesser extent) via 3A4 to hydroxy, desmethyl, and sulfone metabolites (all inactive); saturable first-pass effect

Excretion

Urine (~77% as metabolites, very small amount as unchanged drug); feces

Clearance: 500-600 mL/minute; chronic hepatic disease: 70 mL/minute

Onset of Action

Antisecretory: ~1 hour; Peak effect: Within 2 hours

Time to Peak

Plasma: 0.5 to 3.5 hours

Duration of Action

Up to 72 hours; 50% of maximum effect at 24 hours; after stopping treatment, secretory activity gradually returns over 3 to 5 days; Maximum secretory inhibition: 4 days

Half-Life Elimination

0.5 to 1 hour; hepatic impairment: ~3 hours

Protein Binding

~95%

Special Populations: Renal Function Impairment

There is slight increase in bioavailability in patients whose creatinine clearance ranged between 10 and 62 mL/minute/1.73 m2.

Special Populations: Hepatic Function Impairment

In patients with hepatic impairment (Child-Pugh class A, B, or C), bioavailability is increased ~100%, plasma half-life is increased, and plasma clearance is decreased.

Special Populations: Elderly

The elimination rate is decreased; bioavailability is increased.

Special Populations: Race

AUC is increased approximately 4-fold in Asian patients.

Use: Labeled Indications

Duodenal ulcer (Rx only): Short-term treatment (4 to 8 weeks) of active duodenal ulcer in adults.

Gastric ulcer (Rx only): Short-term treatment (4 to 8 weeks) of active benign gastric ulcer in adults.

Gastroesophageal reflux disease (Rx only):

Treatment of erosive esophagitis: Short-term treatment (4 to 8 weeks) of erosive esophagitis (EE) due to acid-mediated gastroesophageal reflux disease (GERD) diagnosed by endoscopy in patients ≥1 year; short-term treatment (up to 6 weeks) of EE due to acid-mediated GERD in pediatric patients 1 month to <1 year.

Maintenance healing of erosive esophagitis: Maintenance healing of EE due to acid-mediated GERD in patients ≥1 year.

Symptomatic gastroesophageal reflux disease: Treatment of heartburn and other symptoms associated with GERD for up to 4 weeks in patients ≥1 year.

Heartburn (OTC only): Treatment of frequent, uncomplicated heartburn (occurring ≥2 or more days per week) in adults.

Helicobacter pylori eradication (Rx only):

Dual therapy: Treatment of H. pylori infection and duodenal ulcer disease (active or up to 1-year history) in combination with clarithromycin to eradicate H. pylori in adults.

Triple therapy: Treatment of H. pylori infection and duodenal ulcer disease (active or up to 1-year history) in combination with clarithromycin and amoxicillin to eradicate H. pylori in adults.

Pathological hypersecretory conditions (Rx only): Long-term treatment of pathological hypersecretory conditions (eg, Zollinger-Ellison syndrome, multiple endocrine adenomas, systemic mastocytosis) in adults.

Use: Unlabeled

Healing NSAID-induced ulcers; prevention of NSAID-induced ulcer; stress ulcer prophylaxis in the critically-ill

Contraindications

Hypersensitivity (eg, anaphylaxis, anaphylactic shock, angioedema, bronchospasm, interstitial nephritis, urticaria) to omeprazole, other substituted benzimidazole proton pump inhibitors, or any component of the formulation; concomitant use with products that contain rilpivirine

OTC labeling: When used for self-medication (OTC), do not use if trouble or pain when swallowing food; vomiting with blood, or bloody or black stools; heartburn with lightheadedness, dizziness, or sweating; chest pain or shoulder pain with shortness of breath, sweating, pain spreading to arms, neck or shoulders, or lightheadedness; frequent chest pain.

Dosing: Adult

Duodenal ulcer: Oral: 20 mg once daily for 4 weeks; some patients may require an additional 4 weeks. Up to 40 mg once daily has been used in patients with ulcers refractive to other therapies (eg, H2 antagonists) (Bardhan 1991).

Gastric ulcers: Oral: 40 mg once daily for 4 to 8 weeks; in clinical trials, healing rates of ulcers ≤1 cm at 4 and 8 weeks were similar between omeprazole 20 mg and 40 mg; for ulcers >1 cm omeprazole 40 mg was significantly more effective at 8 weeks.

Symptomatic GERD (without esophageal lesions): Oral: 20 mg once daily for up to 4 weeks

Erosive esophagitis: Oral:

Treatment:

Manufacturer's labeling: 20 mg once daily for 4 to 8 weeks; may continue for an additional 4 weeks if no response to 8 weeks of treatment. With recurrence of erosive esophagitis or GERD symptoms (eg, heartburn), an additional 4 to 8 weeks of treatment may be considered.

Alternate recommendations: For patients with partial response to usual dosing, may consider a dose increase to 20 mg twice daily (Kahrilas 2008; Katz 2013) or 40 mg once or twice daily (NICE 2014).

Maintenance of healing: 20 mg once daily; 10 mg once daily is recommended for Asian patients.

Helicobacter pylori eradication: Oral: Dose varies with regimen:

Manufacturer labeling:

Dual therapy: 40 mg once daily administered with clarithromycin 500 mg 3 times daily for 14 days. In patients with presence of ulcer at time of therapy initiation, continue omeprazole 20 mg once daily for an additional 14 days after completion of dual therapy.

Triple therapy: 20 mg twice daily administered with amoxicillin 1000 mg and clarithromycin 500 mg twice daily for 10 days. In patients with presence of ulcer at time of therapy initiation, continue omeprazole 20 mg once daily for an additional 18 days after completion of triple therapy.

American College of Gastroenterology guidelines (Chey 2007):

Nonpenicillin allergy: 20 mg twice daily administered with amoxicillin 1000 mg and clarithromycin 500 mg twice daily for 10 to 14 days

Penicillin allergy: 20 mg twice daily administered with clarithromycin 500 mg and metronidazole 500 mg twice daily for 10 to 14 days or 20 mg once or twice daily administered with bismuth subsalicylate 525 mg and metronidazole 250 mg plus tetracycline 500 mg 4 times daily for 10 to 14 days

Pathological hypersecretory conditions: Oral: Initial: 60 mg once daily; doses up to 120 mg 3 times daily have been administered; administer daily doses >80 mg in divided doses. Treat as long as clinically indicated; some patients have been treated continuously for >5 years.

NSAID-induced ulcer treatment (off-label use): Oral: 20 mg once daily for 4 to 8 weeks; Maintenance: 20 mg once daily for up to 6 months (Hawkey 1998)

NSAID-induced ulcer prophylaxis (off-label use): Oral: 20 mg once daily for up to 6 months (Cullen 1998)

Stress ulcer prophylaxis, ICU patients (off-label use): Oral: 40 mg once daily (Levy 1997) or may administer 40 mg loading dose followed by 20 to 40 mg once daily (ASHP 1999). Note: Intended for patients with associated risk factors (eg, coagulopathy, mechanical ventilation for ≥48 hours, severe sepsis); discontinue use once risk factors have resolved (Dellinger 2013). Omeprazole 20 mg via NG tube once daily may be less effective in some critically ill populations compared to 40 mg via NG tube once daily (Balaban 1997).

Heartburn (OTC only): Oral: 20 mg once daily for 14 days; treatment may be repeated after 4 months if needed.

Dosing: Geriatric

Refer to adult dosing. Bioavailability may be increased in elderly patients.

Dosing: Pediatric

Symptomatic GERD: Children ≥1 year to Adolescents ≤16 years: Oral:

5 kg to <10 kg: 5 mg once daily for up to 4 weeks

10 kg to <20 kg: 10 mg once daily for up to 4 weeks

≥20 kg: 20 mg once daily for up to 4 weeks

Erosive esophagitis, treatment:

Infants 1 month to <1 year: Oral:

3 kg to <5 kg: 2.5 mg once daily for up to 6 weeks

5 kg to <10 kg: 5 mg once daily for up to 6 weeks

≥10 kg: 10 mg once daily for up to 6 weeks

Children ≥1 year to Adolescents ≤16 years: Oral: Note: Duration of therapy is up to 4 to 8 weeks; may continue for an additional 4 weeks if no response to 8 weeks of treatment. With recurrence of erosive esophagitis or GERD symptoms (eg, heartburn), an additional 4 to 8 week course may be considered.

5 kg to <10 kg: 5 mg once daily

10 kg to <20 kg: 10 mg once daily

≥20 kg: 20 mg once daily

Erosive esophagitis maintenance of healing: Children ≥1 year to Adolescents ≤16 years: Oral: Note: Studies do not extend beyond 12 months.

5 kg to <10 kg: 5 mg once daily

10 kg to <20 kg: 10 mg once daily

≥20 kg: 20 mg once daily

Dosing: Renal Impairment

No dosage adjustment necessary.

Dosing: Hepatic Impairment

US labeling: Mild to severe impairment (Child-Pugh class A, B, or C): 10 mg once daily when used for maintenance of healing of erosive esophagitis. There are no dosage adjustments provided for the other indications.

Canadian labeling: Maximum dose: 20 mg/day.

Reconstitution

Granules for oral suspension: For oral administration, empty the contents of the 2.5 mg packet into 5 mL of water (10 mg packet into 15 mL of water); stir. For NG administration, add 5 mL of water into a catheter-tipped syringe, and then add the contents of a 2.5 mg packet (15 mL water for the 10 mg packet); immediately shake syringe. Note: Regardless of the route of administration, the suspension should be left to thicken for 2 to 3 minutes prior to administration.

Extemporaneously Prepared

Note: More palatable omeprazole (2 mg/mL) suspensions are commercially available as compounding kits (First-Omeprazole, Omeprazole+Syrspend SF Alka Cherry Kit).

A 2 mg/mL oral omeprazole solution (Simplified Omeprazole Solution) may be made with five omeprazole 20 mg delayed release capsules and 50 mL sodium bicarbonate 8.4%. Empty capsules into beaker. Add sodium bicarbonate solution. Gently stir (about 15 minutes) until a white suspension forms. Transfer to amber-colored syringe or bottle. Stable for 14 days at room temperature or for 30 days refrigerated.

DiGiacinto JL, Olsen KM, Bergman KL, et al, “Stability of Suspension Formulations of Lansoprazole and Omeprazole Stored in Amber-Colored Plastic Oral Syringes,” Ann Pharmacother, 2000, 34(5):600-5. 10852086Quercia R, Fan C, Liu X, et al, “Stability of Omeprazole in an Extemporaneously Prepared Oral Liquid,” Am J Health Syst Pharm, 1997, 54(16):1833-6. 9269520Sharma V, “Comparison of 24-hour Intragastric pH Using Four Liquid Formulations of Lansoprazole and Omeprazole,” Am J Health Syst Pharm, 1999, 56(23 Suppl 4):18-21.10597120

Administration

Oral: Administer before meals; may take with antacids.

Capsule: Swallow whole; do not chew or crush. Capsule may be opened and contents mixed with 1 tablespoon of applesauce (soft enough to swallow without chewing). Swallow immediately with a glass of cool water; mixture should not be chewed, crushed, warmed, or saved for future use.

Oral suspension: Following reconstitution, the suspension should be left to thicken for 2 to 3 minutes and administered within 30 minutes. If any material remains after administration, add more water, stir, and administer immediately.

Tablet: Swallow whole with a glass of water before morning meal; do not crush or chew.

Nasogastric/Gastric tube:

Oral suspension (using packets): Add 5 mL of water to a catheter tipped syringe and then add contents of a 2.5 mg packet (or 15 mL of water for the 10 mg packet). Immediately shake syringe and leave to thicken for 2 to 3 minutes; shake syringe again and within 30 minutes administer via NG or gastric tube (French size 6 or larger). Refill syringe with an equal amount of water, shake, and flush remaining contents through NG or gastric tube

Oral suspension (using capsules): The manufacturer of Prilosec does not give recommendations for extemporaneous preparation of omeprazole capsules for NG/OG administration. Consider using the packets for oral suspension. If packets are unavailable, methods of preparation of capsules for NG/OG administration have been described (Balaban 1997; Phillips 1996). An extemporaneously prepared suspension with extended stability may also be used (DiGiacinto 2000; Quercia 1997; Sharma 1999).

Dietary Considerations

Administer before meals.

Storage

Capsules, tablets: Store at 15°C to 30°C (59°F to 86°F). Protect from light and moisture.

Granules for oral suspension: Store at 25°C (77°F); excursions permitted to 15°C to 30°C (59°F to 86°F).

Powder for suspension (compounding kits): Refer to manufacturer's labeling.

OTC capsules: Store at 20°C to 25°C (68°F to 77°F); protect from moisture.

Drug Interactions

Amphetamine: Proton Pump Inhibitors may increase the absorption of Amphetamine. Monitor therapy

Antihepaciviral Combination Products: May decrease the serum concentration of Omeprazole. Monitor therapy

Atazanavir: Proton Pump Inhibitors may decrease the serum concentration of Atazanavir. Management: See full drug interaction monograph for details. Consider therapy modification

Bisphosphonate Derivatives: Proton Pump Inhibitors may diminish the therapeutic effect of Bisphosphonate Derivatives. Monitor therapy

Bosentan: CYP2C9 Inhibitors (Moderate) may increase the serum concentration of Bosentan. Management: Concomitant use of both a CYP2C9 inhibitor and a CYP3A inhibitor or a single agent that inhibits both enzymes with bosentan is likely to cause a large increase in serum concentrations of bosentan and is not recommended. See monograph for details. Monitor therapy

Bosutinib: Proton Pump Inhibitors may decrease the serum concentration of Bosutinib. Management: Consider alternatives to proton pump inhibitors, such as antacids or H2 receptor antagonists. Administer alternative agents more than 2 hours before or after bosutinib. Consider therapy modification

Cannabis: CYP2C9 Inhibitors (Moderate) may increase the serum concentration of Cannabis. More specifically, tetrahydrocannabinol serum concentrations may be increased. Monitor therapy

Carvedilol: CYP2C9 Inhibitors (Moderate) may increase the serum concentration of Carvedilol. Specifically, concentrations of the S-carvedilol enantiomer may be increased. Monitor therapy

Cefditoren: Proton Pump Inhibitors may decrease the serum concentration of Cefditoren. Management: If possible, avoid use of cefditoren with proton pump inhibitors (PPIs). Consider alternative methods to minimize/control acid reflux (eg, diet modification) or alternative antimicrobial therapy if use of PPIs can not be avoided. Consider therapy modification

Cilostazol: CYP2C19 Inhibitors may increase the serum concentration of Cilostazol. Management: Consider reducing the cilostazol dose to 50 mg twice daily in patients who are also receiving inhibitors of CYP2C19. Consider therapy modification

Citalopram: CYP2C19 Inhibitors (Moderate) may increase the serum concentration of Citalopram. Management: Limit citalopram dose to a maximum of 20 mg/day if used with a moderate CYP2C19 inhibitor. Patients using this combination should be monitored closely for evidence of citalopram toxicity (e.g., serotonin syndrome, QT prolongation, etc.). Consider therapy modification

Clopidogrel: Omeprazole may diminish the antiplatelet effect of Clopidogrel. Omeprazole may decrease serum concentrations of the active metabolite(s) of Clopidogrel. Avoid combination

CloZAPine: Omeprazole may decrease the serum concentration of CloZAPine. Omeprazole may increase the serum concentration of CloZAPine. Monitor therapy

CycloSPORINE (Systemic): Omeprazole may increase the serum concentration of CycloSPORINE (Systemic). Monitor therapy

CYP2C19 Inducers (Strong): May increase the metabolism of CYP2C19 Substrates. Management: Consider an alternative for one of the interacting drugs. Some combinations may be specifically contraindicated. Consult appropriate manufacturer labeling. Consider therapy modification

CYP2C19 Substrates: CYP2C19 Inhibitors (Moderate) may decrease the metabolism of CYP2C19 Substrates. Monitor therapy

CYP2C9 Substrates: CYP2C9 Inhibitors (Moderate) may decrease the metabolism of CYP2C9 Substrates. Monitor therapy

Cysteamine (Systemic): Proton Pump Inhibitors may diminish the therapeutic effect of Cysteamine (Systemic). Monitor therapy

Dabigatran Etexilate: Proton Pump Inhibitors may decrease serum concentrations of the active metabolite(s) of Dabigatran Etexilate. Monitor therapy

Dabrafenib: May decrease the serum concentration of CYP2C19 Substrates. Management: Seek alternatives to the CYP2C19 substrate when possible. If concomitant therapy cannot be avoided, monitor clinical effects of the substrate closely (particularly therapeutic effects). Consider therapy modification

Dabrafenib: Proton Pump Inhibitors may decrease the serum concentration of Dabrafenib. Dabrafenib may decrease the serum concentration of Proton Pump Inhibitors. Management: Seek alternatives to the proton pump inhibitor when possible. If concomitant therapy cannot be avoided, monitor for diminished effects of both drugs. Consider therapy modification

Darunavir: May decrease the serum concentration of Omeprazole. Monitor therapy

Dasatinib: Proton Pump Inhibitors may decrease the serum concentration of Dasatinib. Management: Antacids (taken 2 hours before or after dasatinib administration) can be used in place of the proton pump inhibitor if some acid-reducing therapy is needed. Avoid combination

Delavirdine: Proton Pump Inhibitors may decrease the serum concentration of Delavirdine. Management: Chronic therapy with proton pump inhibitors (PPIs) should be avoided in patients treated with delavirdine. The clinical significance of short-term PPI therapy with delavirdine is uncertain, but such therapy should be undertaken with caution. Avoid combination

Dexmethylphenidate: Proton Pump Inhibitors may increase the absorption of Dexmethylphenidate. Specifically, proton pump inhibitors may interfere with the normal release of drug from the extended-release capsules (Focalin XR brand), which could result in both increased absorption (early) and decreased delayed absorption. Monitor therapy

Dextroamphetamine: Proton Pump Inhibitors may increase the absorption of Dextroamphetamine. Specifically, the dextroamphetamine absorption rate from mixed amphetamine salt extended release (XR) capsules may be increased in the first hours after dosing. Monitor therapy

Dronabinol: CYP2C9 Inhibitors (Moderate) may increase the serum concentration of Dronabinol. Monitor therapy

Enzalutamide: May decrease the serum concentration of CYP2C19 Substrates. Conversely, concentrations of active metabolites may be increased for those drugs activated by CYP2C19. Management: Concurrent use of enzalutamide with CYP2C19 substrates that have a narrow therapeutic index should be avoided. Use of enzalutamide and any other CYP2C19 substrate should be performed with caution and close monitoring. Consider therapy modification

Erlotinib: Proton Pump Inhibitors may decrease the serum concentration of Erlotinib. Avoid combination

Escitalopram: Omeprazole may increase the serum concentration of Escitalopram. Management: Monitor for increased escitalopram toxicity with concomitant use of omeprazole. Recommendations for management of this interaction found in product labeling may differ by country. Consult appropriate labeling. Consider therapy modification

Fluconazole: May increase the serum concentration of Proton Pump Inhibitors. Monitor therapy

Fosphenytoin: Omeprazole may increase the serum concentration of Fosphenytoin. Fosphenytoin may decrease the serum concentration of Omeprazole. Monitor therapy

Gefitinib: Proton Pump Inhibitors may decrease the serum concentration of Gefitinib. Management: Avoid use of proton pump inhibitors (PPIs) with gefitinib when possible. If required, administer gefitinib 12 hours after administration of the PPI or 12 hours before the next dose of the PPI. Consider therapy modification

Indinavir: Proton Pump Inhibitors may decrease the serum concentration of Indinavir. Monitor therapy

Iron Salts: Proton Pump Inhibitors may decrease the absorption of Iron Salts. Exceptions: Ferric Carboxymaltose; Ferric Citrate; Ferric Gluconate; Ferric Hydroxide Polymaltose Complex; Ferric Pyrophosphate Citrate; Ferumoxytol; Iron Dextran Complex; Iron Sucrose. Monitor therapy

Itraconazole: Proton Pump Inhibitors may decrease the serum concentration of Itraconazole. Consider therapy modification

Ketoconazole (Systemic): Proton Pump Inhibitors may decrease the serum concentration of Ketoconazole (Systemic). Ketoconazole (Systemic) may increase the serum concentration of Proton Pump Inhibitors. Consider therapy modification

Ledipasvir: Proton Pump Inhibitors may decrease the serum concentration of Ledipasvir. Management: Avoid the use of PPIs at doses greater than the equivalent of omeprazole 20 mg, avoid administration of PPIs within 2 hours prior to ledipasvir dosing, and avoid use of PPIs in combination with food. Consider therapy modification

Lumacaftor: May decrease the serum concentration of CYP2C19 Substrates. Monitor therapy

Mesalamine: Proton Pump Inhibitors may diminish the therapeutic effect of Mesalamine. Proton pump inhibitor-mediated increases in gastrointestinal pH may cause the premature release of mesalamine from specific sustained-release mesalamine products. Management: Consider avoiding concurrent administration of high-dose proton pump inhibitors (PPIs) with sustained-release mesalamine products. Consider therapy modification

Methotrexate: Proton Pump Inhibitors may increase the serum concentration of Methotrexate. Monitor therapy

Methylphenidate: Proton Pump Inhibitors may increase the absorption of Methylphenidate. Specifically, proton pump inhibitors may interfere with the normal release of drug from the extended-release capsules (Ritalin LA brand), which could result in both increased absorption (early) and decreased delayed absorption. Monitor therapy

Multivitamins/Minerals (with ADEK, Folate, Iron): Proton Pump Inhibitors may decrease the serum concentration of Multivitamins/Minerals (with ADEK, Folate, Iron). Specifically, the absorption of iron may be decreased. Monitor therapy

Mycophenolate: Proton Pump Inhibitors may decrease the serum concentration of Mycophenolate. Specifically, concentrations of the active mycophenolic acid may be reduced. Monitor therapy

Nalmefene: Omeprazole may decrease the serum concentration of Nalmefene. Monitor therapy

Nelfinavir: Proton Pump Inhibitors may decrease serum concentrations of the active metabolite(s) of Nelfinavir. Proton Pump Inhibitors may decrease the serum concentration of Nelfinavir. Avoid combination

Nilotinib: Proton Pump Inhibitors may decrease the serum concentration of Nilotinib. Management: Avoid this combination when possible since separation of doses is not likely to be an adequate method of minimizing the interaction. Consider therapy modification

PAZOPanib: Proton Pump Inhibitors may decrease the serum concentration of PAZOPanib. Avoid combination

Phenytoin: May decrease the serum concentration of Omeprazole. Omeprazole may increase the serum concentration of Phenytoin. Monitor therapy

Posaconazole: Proton Pump Inhibitors may decrease the serum concentration of Posaconazole. Consider therapy modification

Raltegravir: Proton Pump Inhibitors may increase the serum concentration of Raltegravir. Monitor therapy

RifAMPin: May decrease the serum concentration of Omeprazole. Avoid combination

Rilpivirine: Proton Pump Inhibitors may decrease the serum concentration of Rilpivirine. Avoid combination

Riociguat: Proton Pump Inhibitors may decrease the serum concentration of Riociguat. Monitor therapy

Risedronate: Proton Pump Inhibitors may diminish the therapeutic effect of Risedronate. Proton Pump Inhibitors may increase the serum concentration of Risedronate. This applies specifically to use of delayed-release risedronate. Avoid combination

Saquinavir: Proton Pump Inhibitors may increase the serum concentration of Saquinavir. Monitor therapy

St John's Wort: May decrease the serum concentration of Omeprazole. Avoid combination

Tacrolimus (Systemic): Proton Pump Inhibitors may increase the serum concentration of Tacrolimus (Systemic). Management: Tacrolimus dose adjustment may be required. Rabeprazole, pantoprazole, or selected H2-receptor antagonists (i.e., ranitidine or famotidine) may be less likely to interact. Genetic testing may predict patients at highest risk. Consider therapy modification

Tetrahydrocannabinol: CYP2C9 Inhibitors (Moderate) may increase the serum concentration of Tetrahydrocannabinol. Monitor therapy

Tipranavir: May decrease the serum concentration of Proton Pump Inhibitors. These data are derived from studies with Ritonavir-boosted Tipranavir. Monitor therapy

TiZANidine: CYP1A2 Inhibitors (Weak) may increase the serum concentration of TiZANidine. Management: Avoid these combinations when possible. If combined use cannot be avoided, initiate tizanidine at an adult dose of 2 mg and increase in 2-4 mg increments based on patient response. Monitor for increased effects of tizanidine, including adverse reactions. Consider therapy modification

Velpatasvir: Proton Pump Inhibitors may decrease the serum concentration of Velpatasvir. Avoid combination

Vitamin K Antagonists (eg, warfarin): Omeprazole may increase the serum concentration of Vitamin K Antagonists. Monitor therapy

Voriconazole: May increase the serum concentration of Proton Pump Inhibitors. Proton Pump Inhibitors may increase the serum concentration of Voriconazole. Management: In patients receiving omeprazole 40 mg/day or greater, reduce omeprazole dose by half when initiating voriconazole. Monitor therapy

Test Interactions

Omeprazole may falsely elevate serum chromogranin A (CgA) levels. The increased CgA level may cause false-positive results in the diagnosis of a neuroendocrine tumor. Temporarily stop omeprazole ≥14 days prior to assessing CgA level; repeat level if initially elevated; use the same laboratory for all testing of CgA levels.

Adverse Reactions

1% to 10%:

Central nervous system: Headache (7%), dizziness (2%)

Dermatologic: Skin rash (2%)

Gastrointestinal: Abdominal pain (5%), diarrhea (4%), nausea (4%), flatulence (3%), vomiting (3%), acid regurgitation (2%), constipation (2%)

Neuromuscular & skeletal: Back pain (1%), weakness (1%)

Respiratory: Upper respiratory infection (2%), cough (1%)

<1% (Limited to important or life-threatening; adverse event occurrence may vary based on formulation): Abdominal swelling, abnormal dreams, aggression, agranulocytosis, allergic reactions, alopecia, anaphylaxis, anemia, angina pectoris, angioedema, anorexia, apathy, arthralgia, atrophic gastritis, benign gastric polyps, blurred vision, bone fracture, bradycardia, bronchospasm, chest pain, cholestatic hepatitis, chronic renal disease (Lazarus 2016), Clostridium difficile-associated diarrhea (CDAD), confusion, depression, dermatitis, diplopia, drowsiness, epistaxis, erythema multiforme, esophageal candidiasis, fecal discoloration, gastroduodenal carcinoids, glycosuria, gynecomastia, hallucinations, hematuria, hemolytic anemia, hepatic disease (hepatocellular, cholestatic, mixed), hepatic encephalopathy, hepatic failure, hepatic necrosis, hepatitis, hepatocellular hepatitis, hepatotoxicity (idiosyncratic) (Chalasani 2014), hyperhidrosis, hypersensitivity, hypertension, hypocalcemia, hypoglycemia, hypokalemia, hypomagnesemia, hyponatremia, increased gamma glutamyl transferase, increased serum alkaline phosphatase, increased serum bilirubin, increased serum creatinine, increased serum transaminases, insomnia, interstitial nephritis, irritable bowel syndrome, jaundice, leg pain, leukocytosis, leukopenia, malaise, microscopic colitis, microscopic pyuria, mucosal atrophy (tongue), muscle cramps, myalgia, myasthenia, nervousness, neutropenia, ocular irritation, optic atrophy, optic neuritis, optic neuropathy (anterior ischemic), osteoporosis-related fracture, pain, palpitation, pancreatitis, pancytopenia, paresthesia, peripheral edema, petechiae, photophobia, pneumonia, proteinuria, pruritus, psychiatric disturbance, purpura, sleep disturbance, sore throat, Stevens-Johnson syndrome, stomatitis, tachycardia, testicular pain, thrombocytopenia, toxic epidermal necrolysis, tremor, urinary tract infection, urticaria, weight gain, xeroderma, xerophthalmia, xerostomia

Warnings/Precautions

Concerns related to adverse effects:

• Atrophic gastritis: Long-term omeprazole therapy has caused atrophic gastritis (identified by biopsy).

• Carcinoma: In long-term (2-year) studies in rats, omeprazole produced a dose-related increase in gastric carcinoid tumors. While available endoscopic evaluations and histologic examinations of biopsy specimens from human stomachs have not detected a risk from short-term exposure to omeprazole, further human data on the effect of sustained hypochlorhydria and hypergastrinemia are needed to rule out the possibility of an increased risk for the development of tumors in humans receiving long-term therapy.

Clostridium difficile-associated diarrhea (CDAD): Use of proton pump inhibitors (PPIs) may increase risk of CDAD, especially in hospitalized patients; consider CDAD diagnosis in patients with persistent diarrhea that does not improve. Use the lowest dose and shortest duration of PPI therapy appropriate for the condition being treated.

• Fractures: Increased incidence of osteoporosis-related bone fractures of the hip, spine, or wrist may occur with proton pump inhibitor (PPI) therapy. Patients on high-dose (multiple daily doses) or long-term (≥1 year) therapy should be monitored. Use the lowest effective dose for the shortest duration of time, use vitamin D and calcium supplementation, and follow appropriate guidelines to reduce risk of fractures in patients at risk.

• Hypomagnesemia: Reported rarely, usually with prolonged PPI use of >3 months (most cases >1 year of therapy). May be symptomatic or asymptomatic; severe cases may cause tetany, seizures, and cardiac arrhythmias. Consider obtaining serum magnesium concentrations prior to beginning long-term therapy, especially if taking concomitant digoxin, diuretics, or other drugs known to cause hypomagnesemia; and periodically thereafter. Hypomagnesemia may be corrected by magnesium supplementation, although discontinuation of omeprazole may be necessary; magnesium levels typically return to normal within 1 week of stopping.

• Interstitial nephritis: Acute interstitial nephritis has been observed in patients taking PPIs; may occur at any time during therapy and is generally due to an idiopathic hypersensitivity reaction. Discontinue if acute interstitial nephritis develops.

• Vitamin B12 deficiency: Prolonged treatment (>3 years) may lead to vitamin B12 malabsorption and subsequent vitamin B12 deficiency. The magnitude of the deficiency is dose-related and the association is stronger in females and those younger in age (<30 years); prevalence is decreased after discontinuation of therapy (Lam, 2013).

Disease-related concerns:

• Gastric malignancy: Relief of symptoms does not preclude the presence of a gastric malignancy.

• Gastrointestinal infection (eg, Salmonella, Campylobacter): Use of PPIs may increase risk of these infections.

• Hepatic impairment: In patients with hepatic impairment (Child-Pugh class A, B, or C) exposure to omeprazole is increased; dosage reduction is recommended.

Concurrent drug therapy issues:

• Clopidogrel: Proton pump inhibitors (PPIs) may diminish the therapeutic effect of clopidogrel, thought to be due to reduced formation of the active metabolite of clopidogrel. The manufacturer of clopidogrel recommends either avoidance of both omeprazole (even when scheduled 12 hours apart) and esomeprazole or use of a PPI with comparatively less effect on the active metabolite of clopidogrel (eg, pantoprazole). In contrast to these warnings, others have recommended the continued use of PPIs, regardless of the degree of inhibition, in patients with a history of GI bleeding or multiple risk factors for GI bleeding who are also receiving clopidogrel since no evidence has established clinically meaningful differences in outcome; however, a clinically significant interaction cannot be excluded in those who are poor metabolizers of clopidogrel (Abraham, 2010; Levine, 2011).

• Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.

Special populations:

• Asian ethnicity: Bioavailability is increased in patients of Asian descent; dosage reduction is recommended for maintenance healing of erosive esophagitis.

• Elderly: Bioavailability may be increased in the elderly.

Dosage form specific issues:

• Benzyl alcohol and derivatives: Some dosage forms may contain benzyl alcohol; large amounts of benzyl alcohol (≥99 mg/kg/day) have been associated with a potentially fatal toxicity (“gasping syndrome”) in neonates; the “gasping syndrome” consists of metabolic acidosis, respiratory distress, gasping respirations, CNS dysfunction (including convulsions, intracranial hemorrhage), hypotension, and cardiovascular collapse (AAP ["Inactive" 1997]; CDC, 1982); some data suggests that benzoate displaces bilirubin from protein binding sites (Ahlfors, 2001); avoid or use dosage forms containing benzyl alcohol with caution in neonates. See manufacturer’s labeling.

Other warnings/precautions:

• Appropriate use: Helicobacter pylori eradication: Short-term combination therapy (≤7 days) has been associated with a higher incidence of treatment failure. The American College of Gastroenterology recommends 10 to 14 days of therapy (triple or quadruple) for eradication of H. pylori (Chey, 2007).

• Laboratory test interference: Serum chromogranin A (CgA) levels increase secondary to drug-induced decreases in gastric acid; may cause false-positive results in diagnostic investigations for neuroendocrine tumors. Temporarily stop omeprazole treatment at least 14 days before CgA test; if initial CgA levels are high, repeat test to confirm. Use same commercial laboratory for testing to prevent variable results.

• Self-medication (OTC use): When used for self-medication (OTC), notify health care provider before use if any of the following are present: heartburn for >3 months; frequent wheezing, particularly with heartburn; unexplained weight loss; nausea or vomiting; or stomach pain. Discontinue use and notify health care provider if heartburn continues or worsens; diarrhea occurs; if >14 days of therapy is needed; or if >1 course of therapy is needed every 4 months.

Monitoring Parameters

Susceptibility testing is recommended in patients who fail H. pylori-eradication regimen; magnesium levels (prior to initiation of therapy and periodically thereafter).

Pregnancy Considerations

Adverse events have been observed in some animal reproduction studies. An increased risk of hypospadias was reported following maternal use of proton pump inhibitors (PPIs) during pregnancy (Anderka, 2012), but this was based on a small number of exposures and the same association was not found in another study (Erichsen, 2012). Most available studies have not shown an increased risk of major birth defects following maternal use of omeprazole during pregnancy (Diav-Citrin, 2005; Källén, 2001; Lalkin, 1998; Matok, 2012; Pasternak, 2010). When treating GERD in pregnancy, PPIs may be used when clinically indicated (Katz, 2013).

Patient Education

• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)

• Patient may experience headache, nausea, vomiting, diarrhea, or flatulence. Have patient report immediately to prescriber signs of low magnesium (mood changes; muscle pain or weakness; muscle cramps or spasms; seizures; tremors; lack of appetite; severe nausea or vomiting; or an abnormal heartbeat, signs of kidney problems (urinary retention, blood in urine, change in amount of urine passed, or weight gain), severe dizziness, passing out, severe abdominal pain, bone pain, chills, pharyngitis, excessive weight loss, signs of Clostridium difficile (C. diff)-associated diarrhea (stomach pain or cramps, very loose or watery stools, or bloody stools), or signs of Stevens-Johnson syndrome/toxic epidermal necrolysis (red, swollen, blistered, or peeling skin [with or without fever]; red or irritated eyes; or sores in mouth, throat, nose, or eyes) (HCAHPS).

• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for healthcare professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience, and judgment in diagnosing, treating, and advising patients.

Hide