Drug Interaction Report

Talk to your doctor before using naproxen together with lansoprazole. Using these medications together may affect the enteric coating of naproxen, causing the medication to be released too early in the body. This can make naproxen less effective. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

Chronic use of drugs known as proton pump inhibitors including lansoprazole can sometimes cause hypomagnesemia (low blood levels of magnesium), and the risk may be further increased when combined with other medications that also have this effect such as amphotericin B liposomal. In severe cases, hypomagnesemia can lead to irregular heart rhythm, palpitations, muscle spasm, tremor, and seizures. In children, abnormal heart rhythm may cause fatigue, upset stomach, dizziness, and lightheadedness. A dose adjustment or more frequent monitoring by the doctor may be required to safely use both medications. If you are using an over-the-counter proton pump inhibitor medication such as Prilosec OTC, Zegerid OTC or Prevacid 24 HR, you should follow the directions on the package carefully. Do not use the medication more frequently or for a longer period than recommended on the label unless otherwise prescribed by your doctor. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

Ask your doctor before using naproxen together with ethanol (alcohol). Do not drink alcohol while taking naproxen. Alcohol can increase your risk of stomach bleeding caused by naproxen. Call your doctor at once if you have symptoms of bleeding in your stomach or intestines. This includes black, bloody, or tarry stools, or coughing up blood or vomit that looks like coffee grounds. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

Consumer information for this interaction is not currently available.

MONITOR: Smoking cessation may lead to elevated plasma concentrations and enhanced pharmacologic effects of drugs that are substrates of CYP450 1A2 (and possibly CYP450 1A1) and/or certain drugs with a narrow therapeutic index (e.g., flecainide, pentazocine). One proposed mechanism is related to the loss of CYP450 1A2 and 1A1 induction by polycyclic aromatic hydrocarbons in tobacco smoke; when smoking cessation agents are initiated and smoking stops, the metabolism of certain drugs may decrease leading to increased plasma concentrations. The mechanism by which smoking cessation affects narrow therapeutic index drugs that are not known substrates of CYP450 1A2 or 1A1 is unknown. The clinical significance of this interaction is unknown as clinical data are lacking.

MANAGEMENT: Until more information is available, caution is advisable if smoking cessation agents are used concomitantly with drugs that are substrates of CYP450 1A2 or 1A1 and/or those with a narrow therapeutic range. Patients receiving smoking cessation agents may require periodic dose adjustments and closer clinical and laboratory monitoring of medications that are substrates of CYP450 1A2 or 1A1.