Velphoro Drug Interactions

Effects of other agents on the pharmacokinetics of Velphoro: Effect of concomitant medications administrated with Velphoro on its phosphate binding capacity was not measured.
Effect of Velphoro on the pharmacokinetics of other agents: Interaction studies have not been performed in patients on dialysis.
Five in vivo drug-drug interaction studies (n=approx. 40/study) have been conducted with losartan, furosemide, digoxin, warfarin, and omeprazole in healthy human male and female subjects receiving 1,000mg Velphoro 3 times a day with meals. Velphoro did not affect the bioavailability of these drugs as measured by the area under the curve (AUC) when co-administered with Velphoro or given 2 hours later.
In vitro interactions were studied in aqueous solutions which mimic the physico-chemical conditions of the gastro-intestinal tract with or without the presence of phosphate (400mg). The study was conducted at pH 3.0, 5.5 and 8.0 with incubation at 37°C for 6 hours.
Interaction has been observed in in vitro studies with the following drugs: alendronate, atorvastatin, doxercalciferol, doxycycline, levothyroxine and paricalcitol.
Levothyroxine should not be prescribed with Velphoro while doxycycline should be taken at least 1 hour before Velphoro.
Data from clinical studies have shown that Velphoro does not affect the lipid lowering effects of HMG-CoA reductase inhibitors (e.g., atorvastatin and simvastatin). In addition, clinical studies demonstrated no impact of Velphoro on iPTH lowering effect of oral Vitamin D analogues. Changes in Vitamin D and 1,25-dihydroxy Vitamin D levels are minimal and clinically insignificant.
In vitro studies with the following active substances did not show extensive interaction: acetylsalicylic acid, cephalexin, cinacalcet, ciprofloxacin, clopidogrel, enalapril, hydrochlorothiazide, metformin, metoprolol, nifedipine, pioglitazone, simvastatin and quinidine.
Velphoro is almost not adsorbed from the gastrointestinal tract but may affect the bioavailability of other medicinal products. There are no empirical data on avoiding drug interactions between Velphoro and most concomitant oral drugs. For oral medications where a reduction in the bioavailability of that medication would have a clinically significant effect on its safety or efficacy, consider separating the administration of the two drugs. The necessary separation depends upon the absorption characteristics of the medication concomitantly administered, such as the time to reach peak systemic levels and whether the drug is an immediate release or an extended release product. For concomitant treatment with medicinal products with a narrow therapeutic window, caution should be exercised and the clinical effect and adverse events should be monitored, on initiation or dose adjustment of either Velphoro or the concomitant medicinal product, or the physician should consider measuring blood levels.
Laboratory Tests: Velphoro does not affect guaiac based (Haemoccult) or immunological based (iColo Rectal and Hexagon Opti) faecal occult blood tests.