Medications for Metabolic Bone Disease

 

Mechanism of Action

Phosphorus and calcium are two minerals that are vital for keeping your body in good health. In particular, they help to maintain strong, healthy bones and teeth. An important way of regulating phosphate in the body is by controlling the amount of phosphate that is absorbed from your food and excreted by your kidneys.  As a result of kidney disease, excess phosphate starts to build up in the blood.  Phosphate binders help to remove excess phosphate from the body and reduce the amount of phosphate that gets into the blood.  These medicines "bind" the phosphate in the digestive tract by combining with it to form a compound that isn't absorbed into the blood.

 

Phosphate Binders

Drug

Dosage Regimen

Contraindications

Side Effects

Drug Interactions

Calcium Carbonate
(Alka-Mints®; Amitone®; Cal-Plus®; Caltrate®; Chooz®; Gencalc®; Rolaids® Calcium Rich; Tums®)

Oral:
500 mg to 1.5 g divided 2-4 times/day

High blood calcium; Kidney stones; Low blood phosphorus

Headache, high blood calcium, abdominal pain, nausea/vomiting, reduction in kidney function (if stones)

Calcium channel blockers-may have effectiveness reduced
Polystyrene sulfonate-potassium-binding ability is reduced
Thiazide diuretics-can worsen high blood calcium

Calcum Acetate (PhosLo®)

Oral:Initial-2 tablets with each meal; can be increased gradually to 3-4 tablets with each meal

High blood calcium; Kidney stones; Low blood phosphorus

High blood calcium, abdominal pain, headache, thirst, nausea/vomiting

Calcium channel blockers-may have effectiveness reduced
Polystyrene sulfonate-potassium-binding ability is reduced
Thiazide diuretics-can cause high blood calcium

Sevelamer (Renagel®)

Oral: 800-1600 mg 3 times/day with meals; dosage should be adjusted based on the blood phosphorous levels

Hypersensitivity to sevelamer or any component; low blood phosphorus;
bowel obstruction

Vomiting, diarrhea, increased acidity of blood

Sevelamer may bind to some drugs in the gastrointestinal tract and decrease their absorption.

Lanthanum Carbonate
(Fosrenol®)

 Oral: 750 to 1500 mg per day in divided doses with meals, then titrate in increments of 750 mg/day at intervals of 2 to 3 weeks

Maintenance-1500 to 3000 mg per day in divided doses with meals

Hypersensitivity to lanthanum carbonate

Nausea, vomiting, diarrhea

Drugs known to interact with antacids may interact with lanthanum carbonate and result in decreased absorption of the other drug

Magnesium Hydroxide
(Philips’® Milk of Magnesia)

Oral:
Antacid: 5-15 mL up to 4 times/day as needed

Intestinal obstruction; fecal impaction; renal failure; hypersensitivity to any component

Diarrhea, low blood pressure, abdominal cramps, weakness

May cause  decreased absorption of tetracyclines, digoxin, indomethacin or iron salts