Omeprazole

Omeprazole

[omeprazole IV $8.20; omeprazole oral 10 cents]

ADMINISTRATION ROUTES:

• PO, IV

ALTERNATIVE NAMES:

• Dr Reddy’s Omeprazole, Losec, Omezol

ICU INDICATIONS:

1. ulcer prophylaxis
2. upper gastrointestinal bleeding

PRESENTATION AND ADMINISTRATION:

• IV:
  Omeprazole 40mg vial (powder) plus 10ml of specialised solvent
  Use only solvent provided for reconstitution as follows:
  1. draw up 10ml of solvent from the ampoule
  2. slowly add approximately 5ml of solvent to the vial
  3. withdraw as much air as possible from the vial to reduce positive pressure
  4. transfer the remaining solvent in to the vial
  5. rotate and shake the vial to dissolve the powder

  Inject solution over at least two and a half minutes at a rate not exceeding 4ml per minute
  Note: the omeprazole formulation available in the ICU cannot be given by infusion (see DOSAGE for recommendations)
  Store at room temperature
  Protect from light
  Prepare immediately before use.
  Reconstituted solution is stable at room temperature for four hours.

• PO / NG:
  Capsules:
  Dr Reddys Omeprazole Capsules 10mg (purple / yellow), 20mg (purple / light grey), 40mg (yellow / purple)
  Losec Capsules 10mg (pink), 20mg (pink / reddish-brown), 40mg (reddish-brown)
  Omezol Capsules 10mg (pale pink / white), 20mg (pink / white), 40mg (pink / beige)
  Suspension:
  10mg/5ml

  Note: Tablets can be dispersed in water and given via NG immediately following dispersion but only if NG tubes >8Fr. For NG tubes <8Fr, liquid should be used.

DOSAGE:

• IV:
  Ulcer Prophylaxis: 40mg daily (change to oral as soon as possible)
  High dose (for upper GI bleed): 40mg 6-12 hourly
• PO:
  Ulcer Prophylaxis: 40mg daily

DOSAGE IN RENAL FAILURE AND RENAL REPLACEMENT THERAPY:

• Dose as in normal renal function

DOSAGE IN PAEDIATRICS:

• 0.4-0.8mg/kg 12 to 24 hourly

CLINICAL PHARMACOLOGY:

• Omeprazole is a specific inhibition of the H+/K+ ATPase enzyme system at the secretory surface of the gastric parietal cell. Because this enzyme system is regarded as the acid (proton) pump within the gastric mucosa, omeprazole has been characterized as a gastric acid-pump inhibitor, in that it blocks the final step of acid production.

CONTRAINDICATIONS:

1. hypersensitivity to omeprazole

WARNINGS

• Nil

PRECAUTIONS

• General: Nil
• Laboratory Tests: No tests additional to routine ICU tests are indicated
• Drug/Laboratory Test Interactions: None reported

IMPORTANT DRUG INTERACTIONS FOR THE ICU

• Omeprazole can prolong the elimination of diazepam, warfarin and phenytoin, drugs that are metabolized by oxidation in the liver. There have been reports of increased INR and prothrombin time in patients receiving proton pump inhibitors, including omeprazole, and warfarin concomitantly.

ADVERSE REACTIONS

• Body as a Whole:
  Allergic reactions
• Gastrointestinal:
  Abdominal pain, constipation, diarrhoea, flatulence, nausea, vomiting, elevated LFTs
• Renal:
  Interstitial nephritis
• Nervous System:
  Headache, somnolence