Skip to main content

Drug Interactions between gefitinib and Zantac

This report displays the potential drug interactions for the following 2 drugs:

Edit list (add/remove drugs)

Interactions between your drugs

Major

raNITIdine gefitinib

Applies to: Zantac (ranitidine) and gefitinib

ADJUST DOSING INTERVAL: Coadministration with drugs that elevate gastric pH such as H2-receptor antagonists and antacids may decrease the plasma concentrations of gefitinib. According to the manufacturer, the solubility of gefitinib is pH-dependent and decreases sharply between pH 4 and 6, becoming practically insoluble above pH 7. When gefitinib 250 mg was administered to healthy male volunteers (n=26) one hour following two oral 450 mg doses of ranitidine with sodium bicarbonate as needed to achieve a sustained gastric pH above 5.0, mean gefitinib peak plasma concentration (Cmax) and systemic exposure (AUC) decreased by 71% and 47%, respectively, compared to administration of gefitinib alone. High doses of short-acting antacids may have a similar effect if taken regularly in close proximity to gefitinib administration.

MANAGEMENT: The possibility of a diminished therapeutic response to gefitinib should be considered during coadministration with H2-receptor antagonists or antacids. If concomitant treatment is required, the manufacturer recommends administering gefitinib 6 hours before or 6 hours after an H2-receptor antagonist or antacid.

References

  1. "Product Information. Iressa (gefitinib)." Astra-Zeneca Pharmaceuticals (2023):
  2. "Product Information. Apo-Gefitinib (gefitinib)." Apotex Inc (2022):
  3. "Product Information. Iressa (gefitinib)." AstraZeneca UK Ltd (2023):
  4. "Product Information. Iressa (gefitinib)." AstraZeneca Pty Ltd (2021):
  5. Tang W, Tomkinson H, Masson E "Effect of sustained elevated gastric pH levels on gefitinib exposure." Clin Pharmacol Drug Dev 6 (2017): 517-23
View all 5 references

Switch to consumer interaction data

Drug and food interactions

Minor

raNITIdine food

Applies to: Zantac (ranitidine)

H2 antagonists may reduce the clearance of nicotine. Cimetidine, 600 mg given twice a day for two days, reduced clearance of an intravenous nicotine dose by 30%. Ranitidine, 300 mg given twice a day for two days, reduced clearance by 10%. The clinical significance of this interaction is not known. Patients should be monitored for increased nicotine effects when using the patches or gum for smoking cessation and dosage adjustments should be made as appropriate.

References

  1. Bendayan R, Sullivan JT, Shaw C, Frecker RC, Sellers EM "Effect of cimetidine and ranitidine on the hepatic and renal elimination of nicotine in humans." Eur J Clin Pharmacol 38 (1990): 165-9

Switch to consumer interaction data

Therapeutic duplication warnings

No warnings were found for your selected drugs.

Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.

See also

Report options

Loading...
QR code containing a link to this page

Drug Interaction Classification

These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication.
Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan.
Unknown No interaction information available.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer