Contents

Search

lansoprazole (Prevacid)

Tradename: Prevacid. Indications: - short-term treatment of gastric & duodenal ulcers - prevention of stress ulceration - GERD, pyrosis - erosive esophagitis - Helicobacter pylori infection - prevention of upper GI bleed due to hypersecretory conditions - Zollinger-Ellison syndrome [6} Dosage: 1) Ulcer: 15 mg PO QD. 2) Erosive esophagitis: 30 mg PO/IV* QD * IV given over 30 minutes; requires filter [5] Tabs: 15 mg & 30 mg. Suspension: (oral) 15 & 30 mg packets. [4]; Injection: IV form available in 30 mg vials [5] Pharmacokinetics: 1) oral bioavailability is about 80% 2) drug undergoes extensive 1st pass metabolism to primarily inactive metabolites 3) metabolized by cyt P450 2C19 & 3A4 3) elimination 1/2life < 2 hours 4) duration of action > 24 hours, related to prolonged binding of the drug to the parietal cell 5) when discontinued, secretory action returns in 3-5 days Adverse effects: 1) headache 2) abdominal pain 3) diarrhea Drug interactions: 1) drugs that require an acidic gastric pH for absorption a) ketoconazole b) iron salts c) ampicillin d) digoxin e) vitamin B12 2) sucralfate & H2 blockers a) no benefit to using in combination b) may inhibit protonation & activation of proton pump inhibitors 3) any drug which inhibits cyt P450 2C19 or 3A4 can increase lansoprazole levels 4) any drug which induces cyt P450 3A4 can diminish lansoprazole levels 5) lansoprazole induces cyt P450 1A2 -> may diminihs levels of drugs metabolized by cyt P450 1A2 Mechanism of action: 1) suppression of gastric acid secretion by inhibiting H+/K+ ATPase (proton pump) 2) proton pump inhibitors need protonation by parietal cells to be active 3) inhibition of intrinsic factor secretion ??? 4) interacts with sulfhydryl groups proton pump 5) inactive at neutral pH

Interactions

drug interactions drug adverse effects of proton pump inhibitors (PPI)

Related

cytochrome p450 1A2 (cytochrome P3-450, phenacetin deethylase, cytochrome p450-4, CYP1A2) cytochrome P450 2C19 (cytochrome P450 2C17, cytochrome P450 11A, mephenytoin 4-hydroxylase, cytochrome P450 254C, CYP2C19) cytochrome P450 3A4 (cytochrome P450 C3, nifedipine oxidase, P450-PCN1, NF-25, CYP3A4)

General

proton pump inhibitor pyrrole

Properties

INHIBITS: H+/K+ ATPase MISC-INFO: elimination route LIVER pregnancy-category B safety in lactation ?

Database Correlations

PUBCHEM cid=3883

References

  1. The Pharmacological Basis of Therapeutics, 9th ed. Gilman et al, eds. Permagon Press/McGraw Hill, 1996
  2. Drug Information & Medication Formulary, Veterans Affairs, Central California Health Care System, 1st ed., Ravnan et al eds, 1998 - not on National VA formulary
  3. Prescriber's Letter 13(3): 2006 Cytochrome P450 drug interactions Detail-Document#: 220233 (subscription needed) http://www.prescribersletter.com
  4. Prescriber's Letter 8(12):69 2001
  5. Prescriber's Letter 11(8): 2004 New Drug: Prevacid I.V. (Lansoprazole) Injection Detail-Document#: 200806 (subscription needed) http://www.prescribersletter.com
  6. Deprecated Reference

Component-of

amoxicillin/clarithromycin/lansoprazole (PrevPak, ACL) lansoprazole/naproxen (Prevacid PAC)