Calcitonin-Salmon

 Action Decreases rate of bone turnover, presumably by regulating bone metabolism (blocking bone resorption). In conjunction with parathyroid hormone endogenous calcitonin regulates serum calcium.

 Indications Treatment of moderate to severe Paget's disease, postmenopausal osteoporosis, hypercalcemia. Nasal spray for treatment of symptomatic Paget's disease.

 Contraindications Standard considerations.

 Route/Dosage

Paget's Disease

ADULTS: Initial dose: SC/IM 100 IU/day; maintenance: SC/IM 50 IU/day or qod is usually sufficient.

Postmenopausal Osteoporosis

ADULTS: SC/IM 100 IU/day with supplemental calcium and adequate vitamin D intake. Intranasal 200 IU per day, alternating nostrils.

Hypercalcemia

ADULTS: Starting dose: SC/IM 4 IU/kg q 12 hr. Titrate gradually on basis of response to maximum dose of 8 IU/kg q 6 hr.

 Interactions None well documented.

 Lab Test Interferences None well documented.

 Adverse Reactions

DERM: Injection site inflammation; flushing of face or hands; pruritus of ear lobes; edema of feet; skin rashes. EENT: Eye pain; salty taste. GI: Nausea with or without vomiting (decreases with continued administration); anorexia; diarrhea; epigastric discomfort; abdominal pain. GU: Nocturia. OTHER: Feverish sensation.

 Precautions

Pregnancy: Category C. Lactation: Undetermined. Children: Safety and efficacy not established. Allergy: Systemic allergic reactions, including anaphylaxis, may occur. Antibody formation: Circulating antibodies to calcitonin-salmon may occur after 2 to 18 mo of treatment. Treatment may or may not remain effective. Hypocalcemic tetany: May occur with calcitonin, although no cases have been reported. Osteogenic sarcoma: Known to increase in Paget's disease.

 Administration/Storage

• Administer by SC or IM injection. For doses > 2 ml, use IM site.
• Rotate injection sites to prevent skin irritation.
• Give medication at bedtime to reduce nausea and flushing.
• Keep medication under refrigeration.

 Assessment/Interventions

• Obtain patient history, including drug history and any known allergies. Inquire about possible allergy to fish protein.
• Intradermal testing should be considered before first full therapeutic dose is given, to determine hypersensitivity.
• Have epinephrine (1:1000), antihistamines, and resuscitation equipment available in case anaphylaxis occurs.
• Use padded siderails and keep bed in low position if twitching or paresthesia occurs.
• Institute safety precautions to prevent falls.
• During early therapy have parenteral calcium available in case hypocalcemia occurs.
• Monitor serum calcium levels weekly during initial therapy.
• Periodically monitor BUN, serum creatinine, alkaline phosphatase, urinary hydroxyproline excretion (every 24 hr), parathyroid hormone levels, and electrolytes.
• Observe for signs of anaphylaxis, especially early in treatment. Notify physician immediately if any of these signs occur.
• Assess patient for signs of hypocalcemia: Tachycardia, paresthesia, muscle cramps, laryngospasm, twitching, colic, Chvostek's or Trousseau's sign. Notify physician if any of these signs occur.

 Patient/Family Education

• Teach patient aseptic injection technique.
• Instruct patient to rotate injection sites.
• Explain comfort measures to be used for injection sites.
• Emphasize importance of maintaining adequate intake of vitamin D.
• Explain that nausea is a common side effect, usually occurring 30 min after injection, and will lessen during course of therapy.
• Tell patient that other side effects include anorexia, vomiting, diarrhea, and flushing of face, ears, hands, and feet.
• If patient is taking medication for osteoporosis, explain need for maintaining proper levels of total calcium (1.5 g/day) and vitamin D.
• Remind patient that follow-up office visits and lab tests are necessary.
• Caution patient to follow low-calcium diet if ordered and to avoid high-calcium foods such as bok choy, broccoli, canned salmon/sardines, clams, cream soups, milk and dairy products, blackstrap molasses, oysters, spinach, tofu.
• Instruct patient not to take otc medications without consulting physician.