Drug Interaction Report

MONITOR: Drugs that decrease clotting, vasoconstriction, or platelet aggregation may interfere with the therapeutic effect of verteporfin. These agents may antagonize the physiologic responses to local damage of neovascular endothelium induced by activated verteporfin, which include the release of procoagulant and vasoactive factors that result in vessel occlusion. However, the clinical significance is unknown.

MANAGEMENT: If possible, agents such as anticoagulants, thrombolytics, platelet inhibitors, nonsteroidal anti-inflammatory drugs, ginkgo, dong quai, and vasodilators should be discontinued prior to verteporfin therapy. Otherwise, the potential for diminished efficacy of verteporfin should be considered.

MONITOR: Ethanol may increase folic acid elimination and folic acid absorption is decreased in chronic alcoholics. Excessive alcohol consumption may lead to folate deficiency.

MANAGEMENT: Monitoring of patient response to folic acid supplementation if they also consume alcohol regularly may be recommended.

ADJUST DOSING INTERVAL: Administration with food may increase the absorption of calcium. However, foods high in oxalic acid (spinach or rhubarb), or phytic acid (bran and whole grains) may decrease calcium absorption.

MANAGEMENT: Calcium may be administered with food to increase absorption. Consider withholding calcium administration for at least 2 hours before or after consuming foods high in oxalic acid or phytic acid.