Lansoprazole Theophylline

There is a decreased absorption of lansoprazole when it is administered with sucralfate Lansoprazole may decrease tiie effects of ketoconazole, iron salts, and digoxin. When lansoprazole is administered with theophylline, there is an... 

While generally not of major concern, omeprazole may inhibit the metabolism of warfarin, diazepam, and phenytoin lansoprazole may decrease theophylline concentrations. Drug interactions with omeprazole are of particular concern in patients who are considered slow metabolizers, as are approximately 3% of the Caucasian population. Unfortunately, it is unclear which patients have the polymorphic gene variation that makes them slow metabolizers.17 The metabolism of esomeprazole may also be altered in patients with this polymorphic gene variation. Patients on potentially interacting drugs should be monitored for development of drug-related problems. 

CIMETIDINE FAMOTIDINE NIZATIDINE, RANITIDINE BRONCHODILATORS -THEOPHYLLINE t efficacy and adverse effects, including seizures. There is conflicting information associated with ranitidine, famotidine and nizatidine Inhibition of metabolism via CYP1A2, cimetidine being the best known inhibitor Use alternative acid suppression, e.g. a proton pump inhibitor (not omeprazole or lansoprazole) or monitor closely considerable patient variation. Check levels on day 3 and then at 1 week. A 30-50% i dose of theophylline may be required. For doses <400 mg/day, the interaction may not be clinically significant... 

Co-administration of either lansoprazole or pantoprazole in healthy subjects did not affect the steady-state pharmacokinetics of theophylline in therapeutic doses (74). 

Pan WJ, Goldwater DR, Zhang Y, Pilmer BL, Hunt RH. Lack of a pharmacokinetic interaction between lansoprazole or pantoprazole and theophylline. Aliment Pharmacol Ther 2000 14(3) 345-52. 

Acetaminophen, aldrin, alfentanil, amiodarone, aminopyrine, amitriptyline, amprenavir, androstenedione,antipyrine, astemizole, benzphetamine, budesonide, carbamazepine, celecoxib, chlorpromazine, chlorzoxazone, cisapride, clarithromycin, clozapine, cocaine, codeine, cortisol, cyclophosphamide,cyclosporin, dapsone, delavirdine, dextromethorphan, digitoxin, diltiazem, diazepam, erythromycin, 17j3-estradiol, ethinylestradiol, etoposide, felbamate, fentanyl, flutamide, hydroxyarginine, ifosphamide, imipramine, indinavir, ketoconazole, lansoprazole, loratidine, losartan, lovastatin, (iS)"mephen3d in, methadone, mianserin, miconazole, mifepristone, nelfinavir, nevirapine, nicardipine, nifedipine, odansetron, omeprazole, orphenadrine, proguanil, propafenone, quinidine, quinine, rapamycin, retinoic acid, ritonavir, saquinavir, selegiline, serindole, sufentanil, sulfinpyrazone, tacrolimus, tamoxifen, tamsulosin, taxol, teniposide, terfenadine, tetrahydrocannabinol, theophylline, toremifene, triazolam, trimethadone, trimethoprim, troleandomycin, verapamil, warfarin, zatosetron, Zolpidem, zonisamide... 

Omeprazole may cause a small increase in theophylline clearance, and lansoprazole may canse a small decrease in theophylline levels, neither of which are likely to be clinically relevant Pantopra-zole and rabeprazole do not appear to interact with theophylline. 

Lansoprazole 60 mg daily for 9 days caused only a very slight reduction in the steady-state theophylline levels of 14 healthy subjects. Other studies have also shown little or no change in theophylline pharmacokinetics on concurrent use. ... 

Lansoprazole possibly induces cytochrome P450 isoenzyme CYP1A2 (the enzyme by which theophylline is metabolised) to a small extent, but this is unlikely to be significant unless an individual is particularly sensitive to this effect. Other proton pump inhibitors are unlikely to interact with theophylline, and so no special precautions would seem necessary on eoneurrent use. 

Granneman GR, Karol MD, Locke CS, Cavanau JH. Pharmacokinetic interaction between lansoprazole and theophylline. Ther Drug Monit (1995) 17, 460-4. 

Kokufu T, Ihara N, Sugioka N, Koyama H, Ohta T, Mori S, Nakajima K. Effects of lansoprazole on pharmacokinetics and metabolism of theophylline. Eurf Clin Pharmacol (1995) 48, 391-5. 

Ko J-W, Jang I-J, Shin S-G, Flockhart DA. Effect of lansoprazole on theophylline clearance in extensive and poor metabolizers of cytochrome P450 2C19. Clin Pharmacol Ther (1998) 63, 217. 

CYP lAl and 1A2 are engaged in bioconversion of a limited number of drugs, including caffeine and theophylline [20]. Both omeprazole and lansoprazole are able to induce these isoforms in vitro [62,63]. Such induction seems to be transient, as reported for omeprazole in vitro [63]. As to pantoprazole, a less pronounced induction has been reported in rat liver microsomes [64], while only elevated CYPl A1 messenger RNA (mRNA) levels were observed in a human hepatoma cell line [65]. 

Negative results with pantoprazole in this area are less than conclusive, since the interaction potential with theophylline has only been studied at a pantoprazole dose of 30 mg applied by 2-min injections [58], so that the period of liver exposure was lower than in the clinical setting. Even so, a nonsignificant decrease in elimination half-life by 10% was noted. Lansoprazole hastening of theophylline elimination appears inconsiderable from a practical point of view. More important are concerns over possible links between cancerogenesis and inducibility of lA isoforms. The ambiguities of this issue have been mooted previously. In the present context, it may suffice to emphasize that the 1A induction by PPIs is trivial in magnitude, probably transient and may even have positive aspects [41]. 

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