Lanthanum Carbonate

Trade Names:Fosrenol- Tablets, chewable 500 mg- Tablets, chewable 750 mg- Tablets, chewable 1,000 mg

Pharmacology

Inhibits GI absorption of phosphate by forming highly insoluble lanthanum phosphate complex with dietary phosphate released from food during digestion.

Pharmacokinetics

Absorption

Very low absorption (bioavailability less than 0.002%). C _max is 1 ng/mL. Administer with or immediately after food.

Distribution

Highly bound to plasma proteins (more than 99%).

Metabolism

Not metabolized and not a substrate of CYP-450.

Elimination

Elimination half-life is 53 h.

Indications and Usage

Reducing serum phosphate in patients with end-stage renal disease.

Contraindications

None known.

Dosage and Administration

PO Initial dosage is 1,500 mg/day divided and taken with meals. Titrate dose every 2 to 3 wk, generally in increments of 750 mg/day, until acceptable serum phosphate level is reached.

General Advice

• Have patient chew tablets completely before swallowing. Caution patient not to swallow intact tablets.
• In order to bind dietary phosphate efficiently, administer prescribed dose with or immediately after a meal.

Storage/Stability

Store tablets at controlled room temperature (59° to 86°F). Protect from moisture.

Drug Interactions

Do not take within 2 h of lanthanum.

Laboratory Test Interactions

None well documented.

Adverse Reactions

Cardiovascular

Hypotension (16%).

CNS

Headache (21%).

EENT

Rhinitis (7%).

GI

Nausea (36%); vomiting (26%); diarrhea (23%); abdominal pain (17%); constipation (14%).

Metabolic-Nutritional

Hypercalcemia (4%).

Respiratory

Bronchitis (5%).

Miscellaneous

Dialysis graft complications (26%); dialysis graft occlusion (21%).

Precautions

Pregnancy

Category C .

Lactation

Undetermined.

Children

Safety and efficacy not established.

Elderly

No overall differences in safety and efficacy between patients 65 yr age and older compared with younger patients.

Special Risk Patients

Use with caution in patients with acute peptic ulcer, ulcerative colitis, Crohn disease, or bowel obstruction because these populations were not included in clinical studies.

Diagnostic tests

Abdominal x-ray patients taking lanthanum carbonate may have a radio-opaque appearance typical of an imaging agent.

Overdosage

Symptoms

There is no experience with overdosage.

Patient Information

• Advise patient that medication does not replace diet changes and to continue to adhere to prescribed diet.
• Advise patient that dose may be adjusted periodically in order to achieve max benefit.
• Advise patient to take each dose with or immediately after a meal. Caution patient to chew tablets thoroughly before swallowing and not to swallow intact tablets.
• Instruct patients to notify health care provider that they are taking lanthanum prior to an abdominal x-ray.

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