Paricalcitol
Paricalcitol (Zemplar)
Paricalcitol
( pair-ee- KAL-sih-tohl)
Pregnancy Category: C Zemplar (Rx)

Classification: Drug for hyperparathyroidism

Action/Kinetics: Synthetic vitamin D analog that reduces parathyroid hormone levels in chronic renal failure with no significant changes in the incidence of hypercalcemia or hyperphosphatemia. Serum phosphorous, calcium, and calcium x phosphorous product may increase. Peak levels: 5 min which decrease quickly within 2 hr. t 1/2: About 15 hr. Hepatobiliary excretion is most common.

Uses: Prevention and treatment of secondary hyperparathyroidism associated with chronic renal failure.

Contraindications: Evidence of vitamin D toxicity, hypercalemia, or hypersensitivity to any part of the product. Use of phosphate or vitamin D-related compounds concomitantly with paricalcitol.

Special Concerns: Use with caution during lactation or if given with digitalis compounds. Safety and efficacy have not been determined in children.

Side Effects: GI: N&V;, GI bleeding, dry mouth. CV: Palpitation. CNS: Lightheadedness. Respiratory: Pneumonia. Body as a whole: Edema, chills, fever, flu, sepsis, not feeling well.

Overdose Management: Symptoms: Hypercalcemia. Early symptoms include weakness, headache, somnolence, nausea, vomiting, dry mouth, constipation, muscle pain, bone pain, and metallic taste. Late symptoms include anorexia, weight loss, conjunctivitis, pancreatitis, photophobia, rhinorrhea, pruritus, hyperthermia, decreased libido, elevated BUN, hypercholesterolemia, elevated AST and ALT, ectopic calcification, hypertension, cardiac arrhythmias, somnolence, overt psychosis, death (rarely). Treatment: Immediately reduce or discontinue therapy. Institute a low calcium diet and withdraw calcium supplements. Mobilize client, give attention to fluid and electrolyte imbalances, assess ECG abnormalities (especially if also taking digitalis), and undertake hemodialysis or peritoneal dialysis against a calcium-free dialysate. Monitor serum calcium levels frequentlly until normal values are obtained.

Drug Interactions: Digitalis toxicity is potentiated by hypercalcemia.

How Supplied: Injection: 5 mcg/mL

Dosage
?Injection Treat hyperparathyroidism associated with chronic renal failure.
Initial: 0.04-0.1 mcg/kg (2.8 to 7 mcg) as a bolus dose no more frequently than every other day at any time during dialysis. Doses as high as 0.24 mcg/kg (16.8 mcg) have been used safely. If a satisfactory response is not seen, the dose may be increased by 2 to 4 mcg at 2- 4-week intervals. During any dosage adjustment period, monitor serum calcium and phosphorous levels more frequently. If an elevated calcium level or Ca x P product greater than 75 is noted, immediately reduce or stop the drug until parameters are normal. Then, restart at a lower dose. Doses may need to be decreased as the parathyroid levels decrease in response to therapy.