FOSRENOL Dosage & Rx Info | Uses, Side Effects

Fosrenol Generic Name & Formulations

Legal Class

General Description

Lanthanum carbonate 500mg, 750mg, 1000mg; chew tabs.

Pharmacological Class

Phosphate binder.

How Supplied

Tabs 500mg patient pack (2 x 45 tabs)—1; Tabs 750mg patient pack (6 x 15 tabs)—1; Tabs 1000mg patient pack (9 x 10 tabs)—1; Oral pwd stick pack—10; Oral pwd patient pack (9 x 10 stick packs)—1

Manufacturer

Shire US, Inc.

Generic Availability

Mechanism of Action

Fosrenol reduces absorption of phosphate by forming insoluble lanthanum phosphate complexes that pass through the GI tract unabsorbed. Both serum phosphate and calcium phosphate product are reduced as a consequence of the reduced dietary phosphate absorption.

Fosrenol Indications

Indications

To reduce serum phosphate in end-stage renal disease.

Fosrenol Dosage and Administration

Adult

Take with meals. Chew or crush tabs completely before swallowing. Poor dentition or difficulty chewing tabs: consider using oral pwd form. Oral pwd: sprinkle on small quantity of applesauce or similar food and consume immediately; do not dissolve pwd in liquid for administration. Initially 1.5g/day in divided doses. Titrate at 2–3 wk intervals in increments of 750mg/day based on serum phosphate. Usual range: 1.5g–3g.

Children

Not recommended.

Fosrenol Contraindications

Contraindications

Bowel obstruction, including ileus and fecal impaction.

Fosrenol Boxed Warnings

Not Applicable

Fosrenol Warnings/Precautions

Warnings/Precautions

Consider discontinuing for severe GI symptoms without another explanation. Chew tabs: risk of severe GI obstruction/perforation esp. in abnormal GI anatomy (eg, diverticular disease, peritonitis, history of GI surgery, cancer, ulceration) and hypomotility disorders (eg, constipation, ileus, subileus, diabetic gastroparesis). Do not swallow whole; serious GI complications with unchewed or incompletely chewed tabs. Acute peptic ulcer. Ulcerative colitis. Crohn's disease. Monitor serum phosphate levels. Pregnancy. Nursing mothers.

Fosrenol Pharmacokinetics

Absorption

Mean Cmax: 1.0 ng/mL. Mean plasma concentration: ~0.6 ng/mL.

Distribution

Plasma protein bound: >99%.

Elimination

Fecal (94–99%), renal (<2%). Biliary excretion is the predominant route of elimination.

Fosrenol Interactions

Interactions

Separate dosing of drugs that interact with antacids by 2hrs. Antagonizes quinolone antibiotics; give quinolone 1hr before or 4hrs after Fosrenol. If quinolone given for short course, consider eliminating Fosrenol doses scheduled near quinolone intake to improve quinolone absorption. Antagonizes levothyroxine; separate administration by 2hrs, monitor TSH levels. Risk of GI obstruction or perforation with concomitant medications known to potentiate GI effects. Consider monitoring concomitant drugs that have a narrow therapeutic range. May interfere with abdominal x-ray.

Fosrenol Adverse Reactions

Adverse Reactions

Nausea, vomiting, abdominal pain; serious GI effects (obstruction, ileus, subileus, perforation, fecal impaction).

Fosrenol Clinical Trials

See Literature

Fosrenol Note