Lanthanum: what it treats, how to take it, side effects
Last updated September 7, 2026.
**Lanthanum carbonate is a phosphate binder that lowers high blood phosphate in people with kidney failure.** It traps phosphorus from food in your gut so less enters your blood. Chew or crush tablets completely before swallowing because whole or partly chewed tablets can cause serious bowel problems.
What does it treat?
You may receive lanthanum, sold as Fosrenol, for high phosphate with end-stage kidney disease. Your clinician uses blood tests to guide treatment, alongside your prescribed diet and dialysis.
How do you take it?
The labeled adult starting dose is 1,500 mg daily, divided with or immediately after meals. Most patients need 1,500 to 3,000 mg daily; your clinician adjusts it every 2 to 3 weeks using phosphate results. Studies evaluated up to 4,500 mg daily, but the dosing section does not set a universal maximum: follow your prescribed ceiling. Completely chew or crush chewable tablets. Sprinkle oral powder onto a little applesauce and eat immediately; do not dissolve it in liquid or save the mixture. Skip missed doses without doubling. Stop and call your doctor immediately for severe belly symptoms.
Side effects to know
- Common: You may have nausea, vomiting, belly pain, indigestion, diarrhea, or constipation.
- Serious: Stop taking lanthanum and get urgent help for severe belly pain, swelling, or inability to pass gas or stool, which can signal bowel blockage or a tear. Facial swelling or breathing trouble requires emergency help.
Who should not take it?
Do not take it with a lanthanum allergy, bowel blockage, ileus, or impacted stool. Discuss constipation, digestive disease, previous bowel surgery, and difficulty chewing first. Review your oral medicines for spacing requirements. Current labeling recommends a different phosphate binder during pregnancy or breastfeeding. The label gives no specific alcohol restriction; discuss alcohol with your kidney team.
When is it an emergency?
For overdose, call Poison Control at 1-800-222-1222 immediately; headache, nausea, and vomiting are possible signs. Call 911 for collapse, breathing trouble, or inability to wake up. Throat swelling can signal anaphylaxis. Severe belly pain with swelling, vomiting, or inability to pass gas or stool needs emergency department evaluation.
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Common questions
What is the maximum daily dose?
The dosing section reports studies up to 4,500 mg daily. It does not specify a universal maximum. Do not exceed your prescription.
Can I drink alcohol?
The label lists no specific alcohol interaction. That does not establish a safe amount for you. Ask your kidney team how alcohol fits your care plan.
Can I take it while pregnant or breastfeeding?
Current labeling recommends another phosphate binder in both situations. Human safety information is insufficient. Contact your prescriber to arrange an alternative.
Should I take it with food?
Take it during or immediately after meals. It needs food phosphorus to bind. Follow your prescribed low-phosphorus diet.
What are overdose signs?
Headache, nausea, and vomiting can occur. Call Poison Control at 1-800-222-1222 without waiting for symptoms. Call 911 for collapse or breathing trouble.
Which medicines need separate timing?
Take levothyroxine at least 2 hours before or after lanthanum. Take oral quinolone antibiotics at least 1 hour before or 4 hours afterward. Ask your pharmacist to check every oral medicine and antacid.