Medically reviewed on Nov 15, 2018
(oh MEP ra zole)
- Omeprazole Magnesium
Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product
Capsule Delayed Release, Oral:
PriLOSEC: 10 mg [DSC], 20 mg [DSC], 40 mg [DSC]
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)
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; wild berry flavor]
Brand Names: U.S.
- PriLOSEC OTC [OTC]
- Proton Pump Inhibitor
- Substituted Benzimidazole
Proton pump inhibitor; suppresses gastric basal and stimulated acid secretion by inhibiting the parietal cell H+/K+ ATP pump
Hepatic via CYP2C19 primarily and (to a lesser extent) via 3A4 to hydroxy, desmethyl, and sulfone metabolites (all inactive); saturable first-pass effect
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
0.5 to 1 hour; hepatic impairment: ~3 hours
Special Populations: Renal Function Impairment
There is slight increase in bioavailability in patients whose CrCl 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 ~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.
Off Label Uses
Data from two randomized, double-blinded, placebo-controlled parallel design trials support the use of omeprazole for the treatment of dyspepsia [Meineche-Schmidt 2004], [Veldhuyzen van Zanten 2005]. In addition, data from a systematic review support the use of omeprazole for the treatment of patients with ulcer and reflux-like functional dyspepsia [Pinto-Sanchez 2017].
Based on the American College of Gastroenterology (ACG) and Canadian Association of Gastroenterology (CAG) guidelines for the management of dyspepsia, the use of omeprazole is effective and recommended treatment for dyspepsia and functional dyspepsia in patients <60 years of age who are H. pylori negative or who remain symptomatic after H. pylori eradication therapy [ACG/CAG [Moayyedi 2017]].
NSAID-induced ulcer prophylaxis
According to the American College of Gastroenterology 2009 Guidelines for Prevention of NSAID-Related Ulcer Complications, proton pump inhibitors are effective and recommended in the prophylaxis of gastric and duodenal ulcers in patients receiving NSAID therapy [Lanza 2009].
Data from randomized, double-blind, parallel-group studies support the use of omeprazole in the prevention of NSAID-induced gastric and duodenal ulcers [Cullen 1998], [Regula 2006].
NSAID-induced ulcer treatment
Data from a randomized, single-blinded study and randomized, double-blind studies support the use of omeprazole as treatment for NSAID-induced gastric and duodenal ulcers [Bianchi 1998], [Hawkey 1998], [Yeomans 1998].
Stress ulcer prophylaxis in critically ill patients
Data from a prospective randomized clinical trial in patients at high risk for stress ulcer prophylaxis administered either omeprazole or IV ranitidine, support the use of omeprazole for the prevention of stress ulcers [Levy 1997]. Additional trials may be necessary to further define the role of omeprazole in this setting.
Based on the Surviving Sepsis Campaign International Guidelines for the Management of Severe Sepsis and Septic Shock, stress ulcer prophylaxis using a proton pump inhibitor or a histamine H2-receptor antagonist is recommended in sepsis or septic shock patients who have GI bleeding risk factors.
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.
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).
Dyspepsia (off-label use): Oral: 20 mg once daily for up to 4 weeks (Meineche-Schmidt 2004; Pinto-Sanchez 2017; Veldhuyzen van Zanten 2005).
Erosive esophagitis: Oral:
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 (ACG [Katz 2013]; Kahrilas 2008) 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.
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.
GERD, refractory (off-label dose): Oral: For patients with partial response to usual dosing, may consider a dose increase to 20 mg twice daily for 8 weeks (ACG [Katz 2013]; Hershcovici 2010).
GERD, symptomatic (without esophageal lesions): Oral: 20 mg once daily for up to 4 weeks
Heartburn (OTC only): Oral: 20 mg once daily for 14 days; treatment may be repeated after 4 months if needed.
Helicobacter pylori eradication: Oral: Dose varies with regimen:
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 1,000 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; Chey 2017):
Clarithromycin triple regimen: 20 to 40 mg twice daily in combination with clarithromycin 500 mg twice daily and either amoxicillin 1 g twice daily or metronidazole 500 mg 3 times daily; continue regimen for 14 days. Note: Avoid use of clarithromycin triple therapy in patients with risk factors for macrolide resistance (eg, prior macrolide exposure, local clarithromycin resistance rates ≥15%, eradication rates with clarithromycin-based regimens ≤85%) (ACG [Chey 2017]; Fallone 2016).
Bismuth quadruple regimen: 20 mg twice daily in combination with tetracycline 500 mg 4 times daily, metronidazole 250 mg 4 times daily or 500 mg 3 or 4 times daily, and either bismuth subcitrate 120 to 300 mg 4 times daily or bismuth subsalicylate 300 mg 4 times daily; continue regimen for 10 to 14 days.
Concomitant regimen: 20 mg twice daily in combination with amoxicillin 1 g twice daily, clarithromycin 500 mg twice daily, and either metronidazole or tinidazole 500 mg twice daily; continue regimen for 10 to 14 days.
Sequential regimen: 20 mg twice daily plus amoxicillin 1 g twice daily for 5 to 7 days; then continue omeprazole along with clarithromycin 500 mg twice daily, and either metronidazole or tinidazole 500 mg twice daily for 5 to 7 days.
Hybrid regimen: 20 mg twice daily plus amoxicillin 1 g twice daily for 7 days; then continue omeprazole and amoxicillin along with clarithromycin 500 mg twice daily, and either metronidazole or tinidazole 500 mg twice daily for 7 days.
Levofloxacin triple regimen: 20 mg twice daily in combination with amoxicillin 1 g twice daily and levofloxacin 500 mg once daily; continue regimen for 10 to 14 days.
NSAID-induced ulcer prophylaxis (off-label use): Oral: 20 mg once daily for up to 6 months (Cullen 1998; Lanza 2009; Regula 2006).
NSAID-induced ulcer treatment (off-label use): Oral: Initial: 20 mg once daily for 4 to 8 weeks; Maintenance: 20 mg once daily for up to 6 months (Bianchi 1998; Hawkey 1998; Yeomans 1998).
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.
Stress ulcer prophylaxis in critically ill patients (off-label use): Oral or via NG tube: 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, sepsis/septic shock); discontinue use once risk factors have resolved (Rhodes 2017). 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).
Discontinuation of therapy: Oral: Some experts recommend a step-down approach in order to avoid worsening or rebound symptoms. One strategy is to decrease the dose by 50% over 2 to 4 weeks. If the patient is already on the lowest possible dose, alternate-day therapy may be considered. If symptoms worsen during treatment or after discontinuation, patient should be re-evaluated (Kim 2018).
Refer to adult dosing. Bioavailability may be increased in elderly patients.
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
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. Alternatively, a maximum dose of 20 mg/day regardless of indication, has been recommended (Losec Canadian product labeling). In a very small study, omeprazole systemic exposure and half-life increased ~2- and ~3-fold respectively, in patients with mild to severe hepatic impairment.
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.
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
Administer 30 to 60 minutes before meals; may take with antacids. If administering twice daily, first dose should be administered before breakfast and the second dose before dinner (ACG [Katz 2013]; Hershcovici 2010).
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.
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).
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.
Acalabrutinib: Proton Pump Inhibitors may decrease the serum concentration of Acalabrutinib. Avoid combination
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
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
Capecitabine: Proton Pump Inhibitors may diminish the therapeutic effect of Capecitabine. 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
Cefpodoxime: Proton Pump Inhibitors may decrease the serum concentration of Cefpodoxime. Monitor therapy
Cefuroxime: Proton Pump Inhibitors may decrease the absorption of Cefuroxime. Avoid combination
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: Omeprazole may increase the serum concentration of Citalopram. Management: Limit citalopram dose to a maximum of 20 mg/day if used with omeprazole. Consider therapy modification
CloBAZam: Omeprazole may increase serum concentrations of the active metabolite(s) of CloBAZam. Monitor therapy
Clopidogrel: Omeprazole may diminish the antiplatelet effect of Clopidogrel. Omeprazole may decrease serum concentrations of the active metabolite(s) of Clopidogrel. Management: Clopidogrel labeling recommends avoiding concurrent omeprazole due to a possible decrease in clopidogrel effectiveness. Rabeprazole or pantoprazole may be lower-risk alternatives to omeprazole. Consider therapy modification
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 (High risk with Inducers). Management: Consider an alternative for one of the interacting drugs. Some combinations may be specifically contraindicated. Consult appropriate manufacturer labeling. Consider therapy modification
Cysteamine (Systemic): Proton Pump Inhibitors may diminish the therapeutic effect of Cysteamine (Systemic). Monitor therapy
Dabrafenib: May decrease the serum concentration of CYP2C19 Substrates (High risk with Inducers). 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
Dacomitinib: Proton Pump Inhibitors may decrease the serum concentration of Dacomitinib. Management: Avoid concurrent use of dacomitinib with proton pump inhibitors. Antacids may be used. Histamine H2-receptor antagonists (HR2A) may be used if dacomitinib is given at least 6 hours before or 10 hours after the H2RA. Avoid combination
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
Doxycycline: Proton Pump Inhibitors may decrease the bioavailability of Doxycycline. Monitor therapy
Enzalutamide: May decrease the serum concentration of CYP2C19 Substrates (High risk with Inducers). 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 Isomaltoside; 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: PPI doses equivalent to omeprazole 20 mg or lower may be given with ledipasvir under fasted conditions. Administration with higher doses of PPIs, 2 hours after a PPI, or in combination with food and PPIs may reduce ledipasvir bioavailability. Consider therapy modification
Lumacaftor: May decrease the serum concentration of CYP2C19 Substrates (High risk with Inducers). 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
Neratinib: Proton Pump Inhibitors may decrease the serum concentration of Neratinib. Specifically, proton pump inhibitors may reduce neratinib absorption. 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
Secretin: Proton Pump Inhibitors may diminish the diagnostic effect of Secretin. Specifically, use of PPIs may cause a hyperresponse in gastrin secretion in response to secretin stimulation testing, falsely suggesting gastrinoma. Management: Avoid concomitant use of proton pump inhibitors (PPIs) and secretin, and discontinue PPIs several weeks prior to secretin administration, with the duration of separation determined by the specific PPI. See full monograph for details. Consider therapy modification
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
Tipranavir: May decrease the serum concentration of Proton Pump Inhibitors. These data are derived from studies with Ritonavir-boosted Tipranavir. Monitor therapy
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
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.
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%, postmarketing, and/or case reports (adverse event occurrence may vary based on formulation): Abdominal swelling, abnormal dreams, aggression, agitation, agranulocytosis, allergic reactions, alopecia, anaphylaxis, anemia, angina pectoris, angioedema, anorexia, anxiety, apathy, arthralgia, atrophic gastritis, blurred vision, bone fracture, bradycardia, bronchospasm, chest pain, cholestatic hepatitis, Clostridioides (formerly Clostridium) difficile-associated diarrhea (CDAD), colitis (microscopic), confusion, cutaneous lupus erythematosus, depression, dermatitis, diplopia, disturbed sleep, drowsiness, dysgeusia, epistaxis, erythema multiforme, esophageal candidiasis, fatigue, fecal discoloration, fever, gastric carcinoid tumor, gastric polyp (benign), glycosuria, gynecomastia, hallucination, hematuria, hemolytic anemia, hepatic disease (hepatocellular, cholestatic, mixed), hepatic encephalopathy, hepatic failure, hepatic necrosis, hepatitis, hepatocellular hepatitis, hepatotoxicity (idiosyncratic) (Chalasani 2014), hyperhidrosis, hypersensitivity reaction, hypertension, hypocalcemia, hypoglycemia, hypokalemia, hypomagnesemia, hyponatremia, increased gamma glutamyl transferase, increased serum alkaline phosphatase, increased serum ALT, increased serum AST, increased serum bilirubin, increased serum creatinine, insomnia, interstitial nephritis, irritable bowel syndrome, jaundice, leg pain, leukocytosis, leukopenia, malaise, 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, renal disease (chronic; Lazarus 2016), skin photosensitivity, sore throat, Stevens-Johnson syndrome, stomatitis, systemic lupus erythematosus, tachycardia, testicular pain, thrombocytopenia, tinnitus, toxic epidermal necrolysis, tremor, urinary frequency, urinary tract infection, urticaria, vertigo, weight gain, xeroderma, xerophthalmia, xerostomia
Concerns related to adverse effects:
• 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.
• Clostridioides (formerly 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.
• Cutaneous and systemic lupus erythematosus: Has been reported as new onset or exacerbation of existing autoimmune disease; most cases were cutaneous lupus erythematosus (CLE), most commonly, subacute CLE (occurring within weeks to years after continuous therapy). Systemic lupus erythematosus (SLE) is less common (typically occurs within days to years after initiating treatment) and occurred primarily in young adults up to the elderly. Discontinue therapy if signs or symptoms of CLE or SLE occur and refer to specialist for evaluation; most patients improve 4 to 12 weeks after discontinuation of omeprazole.
• 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.
• Fundic gland polyps: Use of proton pump inhibitors (PPIs) increases risk of fundic gland polyps, especially with long-term use >1 year. May occur without symptoms but nausea, vomiting, or abdominal pain may occur; GI bleeding and/or anemia may occur with ulcerated polyps. Diagnosis of polyps may also increase risk for small intestinal blockage. Use the lowest dose and shortest duration of PPI therapy appropriate for the condition being treated.
• 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).
• 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.
• 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.
• 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 2017).
• 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.
Susceptibility testing is recommended in patients who fail H. pylori-eradication regimen; magnesium levels (prior to initiation of therapy and periodically thereafter).
Available data have not shown an increased risk of major birth defects following maternal use of omeprazole during pregnancy.
Recommendations for the treatment of GERD in pregnancy are available. As in nonpregnant patients, lifestyle modifications followed by other medications are the initial treatments (Body 2016; Huerta-Iga 2016; Katz 2013; van der Woude 2014). Based on available data, PPIs may be used when clinically indicated (Body 2016; Matok 2012; Pasternak 2010; van der Woude 2014).
• 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, hematuria, change in amount of urine passed, or weight gain), signs of infection, signs of liver problems (dark urine, fatigue, lack of appetite, nausea, abdominal pain, light-colored stools, vomiting, or jaundice), signs of pancreatitis (severe abdominal pain, severe back pain, severe nausea, or vomiting), signs of lupus (rash on the cheeks or other body parts, sunburn easy, muscle or joint pain, angina or shortness of breath, or swelling in the arms or legs), severe dizziness, passing out, severe abdominal pain, bone pain, chills, pharyngitis, excessive weight loss, severe loss of strength and energy, signs of Clostridium difficile (C. diff)-associated diarrhea (abdominal pain or cramps, severe diarrhea 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 health care 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.
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