Plicamycin

A to Z Drug Facts

Actions Plicamycin inhibits cellular RNA and enzymatic RNA synthesis. It may block the hypercalcemic action of pharmacologic doses of vitamin D. It also acts on osteoclasts and blocks the action of parathyroid hormone. It renders osteoclasts unable to fully respond to parathryoid hormone with the biosynthesis necessary for osteolysis.

 Indications

Adult

Malignant testicular tumors, hypercalcemia and hypercalciuria associated with advanced neoplasms.

Pediatric

Hypercalcemia and hypercalciuria associated with advanced neoplasms.

 Contraindications Thrombocytopenia, thrombocytopathy, coagulation disorders, or increased susceptibility to bleeding caused by other causes; impairment of bone marrow function; pregnancy.

 Route/Dosage

Testicular Tumors

ADULTS AND PEDIATRIC: IV 25 to 30 mcg/kg/day for 8 to 10 days unless significant side effects or toxicity occurs. Do not use > 10 daily doses. Do not exceed 30 mcg/kg/day.

Hypercalcemia and Hypercalciuria Associated with Advanced Neoplasms

ADULTS AND PEDIATRIC: IV 25 mcg/kg/day for 3 or 4 days. Repeat at intervals of ³ 1 wk to achieve desired result or to maintain serum and urinary calcium excretion at normal levels.

Interactions

Calcitonin

Increased hypocalcemic effect may occur when given with calcitonin.

Lab Test Interferences Increased AST, ALT, isocritic and lactic dehydrogenases, alkaline phosphatase, serum bilirubin, ornithine carbamyl transferease, bromsulphalein retention.

 Adverse Reactions

CNS: Drowsiness, weakness, depression, headache, lethargy. DERMATOLOGIC: Rash, facial flushing. GI: Very low potential for nausea and vomiting (12 to 24 hr); elevated LFTs, anorexia, diarrhea, mucositis. HEMATOLOGIC: Bone marrow suppression, especially thrombocytopenia, nadir at 5 to 10 days, hemorrhagic diathesis, elevated bleeding time (rarely). METABOLIC: Decreased serum calcium, phosphorus, potassium. RENAL: Renal tubular necrosis with high doses, increased BUN and serum creatinine. OTHER: Proteinuria.

 Precautions

Pregnancy: Category X. Lactation: Discontinue nursing or the drug. Adults and pediatric: Dosage is based on patient's body weight. Use ideal weight if patient has abnormal fluid retention. Extravasation risk: Local irritation or phlebitis may occur. Refer to your institution specific protocol. Hemorrhagic syndrome: Usually begins with epistaxis. It can start with hematemesis progressing to more widespread GI hemorrhage or to a more generalized bleeding tendency. It is most likely caused by abnormalities in multiple clotting factors and is dose-related. Adjustment in renal insufficiency: Use with extreme caution. Plicamycin Dosage Adjustment in Renal Dysfunction Ccr Percent of usual dose: > 60 mL/min 100 30 to 60 mL/min 75: 10 to 29 mL/min 75 < 10 mL/min 50: Adjustment in hepatic insufficiency Plicamycin may be dosed at 12.5 mcg/kg for the treatment of hypercalcemia.:

 Administration/Storage

• Refrigerate unconstituted vials at 2° to 8°C (36° to 46°F).
• Add 4.9 mL of sterile water for injection to the vial for a final plicamycin concentration of 500 mcg/mL.
• Dilute with 1 L of 5% Dextrose or 0.9% Sodium Chloride. Plicamycin also can be prepared as a bolus injection or diluted in smaller volumes of fluid.
• The reconstituted solution must be prepared immediately prior to injection and any unused solution discarded. Plicamycin is stable for at least 4 to 6 hr at room temperature.
• Administer as IV bolus or infusion.
• Do not filter.
• Slow IV infusion over 4 to 6 hr. Administration by IV bolus and IV infusion over 20 to 30 min, and £ 1 to 3 hr, in 100 to 250 mL of 5% Dextrose or 0.9% Sodium Chloride are also used.
• Antiemetics may help relieve nausea and vomiting.

 Assessment/Interventions

• Obtain platelet count, prothrombin time, and bleeding time frequently during therapy and for several days following the last dose. Discontinue therapy if thrombocytopenia or a significant prolongation of prothrombin or bleeding times occurs.
• Use with extreme caution in patients with preexisting renal or hepatic impairment.
• Stop therapy for leukocytes < 4000/mm³ or platelets < 150,000/mm³, PT > 4 sec greater than control, AST > 600 U/mL, LDH > 2000 U/mL, or BUN > 25 mg/dL.
• Correct electrolyte imbalance (especially hypocalcemia, hypokalemia, and hypophosphatemia) with appropriate therapy prior to treatment.

 Patient/Family Education

• Notify health care provider if any of the following occur: Fever; sore throat; rashes; chills; unusual bleeding or bruising; bloody nose; black tarry stools; dark urine; yellowing of skin/eyes.
• Nausea, vomiting, and stomach upset are common. Avoid sweet, fried, or fatty foods. Eat smaller light meals several times a day. Dry foods (eg, toast, crackers) and liquids (eg, soups, unsweetened apple juice) may be more easily digested. Do not lie down after eating. If this does not help, antinausea drugs may be prescribed.
• Contraceptive measures are recommended during treatment.
• Calcium supplements are sometimes needed during plicamycin therapy.

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Copyright © 2003 Facts and Comparisons
David S. Tatro
A to Z Drug Facts