omeprazole

omeprazole

(oh me' pray zol)

Losec (CAN), Prilosec, Zegerid

Pregnancy Category C

Drug classes

Antisecretory agent

Proton pump inhibitor

Therapeutic actions

Gastric acid-pump inhibitor: Suppresses gastric acid secretion by specific inhibition of the hydrogen-potassium ATPase enzyme system at the secretory surface of the gastric parietal cells; blocks the final step of acid production.

Indications

·        Short-term treatment of active duodenal ulcer

·        First-line therapy in treatment of heartburn or symptoms of GERD

·        Short-term treatment of active benign gastric ulcer

·        GERD, severe erosive esophagitis, poorly responsive symptomatic GERD

·        Long-term therapy: Treatment of pathologic hypersecretory conditions (Zollinger-Ellison syndrome, multiple adenomas, systemic mastocytosis)

·        Eradication of Helicobacter pylori with amoxicillin or metronidazole and clarithromycin

·        Prilosec OTC: Treatment of frequent heartburn (2 or more days per week)

·        Unlabeled use: Posterior laryngitis; enhance efficacy of pancreatin for the treatment of steatorrhea in cystic fibrosis

Contraindications and cautions

·        Contraindicated with hypersensitivity to omeprazole or its components.

·        Use cautiously with pregnancy, lactation.

Available forms

DR capsules—10, 20, 40 mg; DR tablets—20 mg (OTC); powder for oral suspension—20, 40 mg/packet

Dosages

ADULTS

·        Active duodenal ulcer: 20 mg PO daily for 4–8 wk. Should not be used for maintenance therapy.

·        Active gastric ulcer: 40 mg PO daily for 4–8 wk.

·        Severe erosive esophagitis or poorly responsive GERD: 20 mg PO daily for 4–8 wk. Do not use as maintenance therapy. An additional 4–8 wk course can be considered if needed.

·        Pathologic hypersecretory conditions: Individualize dosage. Initial dose is 60 mg PO daily. Doses up to 120 mg tid have been used. Administer daily doses of > 80 mg in divided doses.

·        Frequent heartburn (2 or more days per week): 20 mg (Prilosec OTC tablet) PO once daily before eating in the morning for 14 days. May repeat the 14-day course q 4 mo.

PEDIATRIC PATIENTS

Safety and efficacy not established.

Pharmacokinetics

Route	Onset	Peak
Oral	Varies	0.5–3.5 hr

Metabolism: Hepatic; T_1/2: 0.5–1 hr

Distribution: Crosses placenta; may enter breast milk

Excretion: Bile, urine

Adverse effects

·        CNS: Headache, dizziness, asthenia, vertigo, insomnia, apathy, anxiety, paresthesias, dream abnormalities

·        Dermatologic: Rash, inflammation, urticaria, pruritus, alopecia, dry skin

·        GI: Diarrhea, abdominal pain, nausea, vomiting, constipation, dry mouth, tongue atrophy

·        Respiratory: URI symptoms, cough, epistaxis

·        Other: Cancer in preclinical studies, back pain, fever

Interactions

Drug-drug

·        WARNING: Increased serum levels and potential increase in toxicity of benzodiazepines, phenytoin, warfarin; if these combinations are used, monitor patient very closely

·        Decreased absorption with sucralfate; give these drugs at least 30 min apart

Nursing considerations

Assessment

·        History: Hypersensitivity to omeprazole or any of its components; pregnancy, lactation

·        Physical: Skin lesions; T; reflexes, affect; urinary output, abdominal examination; respiratory auscultation

Interventions

·        Administer before meals. Caution patient to swallow capsules whole—not to open, chew, or crush them. If using oral suspension, empty packet into a small cup containing 2 tbsp of water. Stir and have patient drink immediately; fill cup with water and have patient drink this water. Do not use any other diluent.

·        WARNING: Arrange for further evaluation of patient after 8 wk of therapy for gastroreflux disorders; not intended for maintenance therapy. Symptomatic improvement does not rule out gastric cancer, which did occur in preclinical studies.

·        Administer antacids, if needed.

Teaching points

·        Take the drug before meals. Swallow the capsules whole; do not chew, open, or crush them. If using the oral suspension, empty packet into a small cup containing 2 tablespoons of water. Stir and drink immediately; fill cup with water and drink this water. Do not use any other liquid or food to dissolve the packet. This drug will need to be taken for up to 8 weeks (short-term therapy) or for a prolonged period (> 5 years in some cases).

·        Have regular medical follow-up visits.

·        You may experience these side effects: Dizziness (avoid driving or performing hazardous tasks); headache (request medications); nausea, vomiting, diarrhea (maintain proper nutrition); symptoms of upper respiratory tract infection, cough (do not self-medicate; consult with your health care provider if uncomfortable).

·        Report severe headache, worsening of symptoms, fever, chills.

Adverse effects in Italic are most common; those in Bold are life-threatening.