Lanthanuminteractions

There is a potential for lanthanum carbonate to interact with compounds that bind to cationic antacids (i.e., aluminum-, magnesium-, or calcium-based); therefore, do not take such compounds within 2 hours of dosing with lanthanum carbonate chewable tablets. Oral quinolone antibiotics must be taken at least 1 hour before or 4 hours after lanthanum carbonate chewable tablets. Do not take thyroid hormone replacement therapy within 2 hours of dosing with lanthanum carbonate chewable tablets. Monitoring of TSH levels is recommended in patients receiving both medicinal agents. For oral medications where a reduction in the bioavailability of that medication would have a clinically significant effect on its safety or efficacy, consider separation of the timing of the administration of the two drugs.

7.1 Drugs Binding to

Antacids There is a potential for lanthanum carbonate to interact with compounds which bind to cationic antacids (i.e., aluminum-, magnesium-, or calcium-based); therefore, do not administer such compounds within 2 hours of dosing with lanthanum carbonate. Examples of relevant classes of compounds where antacids have been demonstrated to reduce bioavailability include antibiotics (such as quinolones, ampicillin, and tetracyclines), thyroid hormones, ACE inhibitors, statin lipid regulators, and anti-malarials.

7.2 Quinolone

Antibiotics Co-administration of lanthanum carbonate with quinolone antibiotics may reduce the extent of their absorption. The bioavailability of oral ciprofloxacin was decreased by approximately 50% when taken with lanthanum carbonate in a single-dose study in healthy volunteers. Administer oral quinolone antibiotics at least 1 hour before or 4 hours after lanthanum carbonate. When oral quinolones are given for short courses, consider eliminating the doses of lanthanum carbonate that would normally be scheduled near the time of quinolone intake to improve quinolone absorption.

7.3 Levothyroxine

The bioavailability of levothyroxine was decreased by approximately 40% when taken together with lanthanum carbonate. Administer thyroid hormone replacement therapy at least 2 hours before or 2 hours after dosing with lanthanum carbonate and monitor thyroid stimulating hormone (TSH) levels.

7.4 Use with

Other Oral Medications There are no empirical data on avoiding drug interactions between lanthanum carbonate 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 separation of the timing of the administration of the two drugs. The duration of 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. Consider monitoring clinical responses or blood levels of concomitant medications that have a narrow therapeutic range.