calcitonin (salmon)
Calcimar, Miacalcin, Salmonine

Available forms
Available by prescription only
Injection: 200-IU/ml, 2-ml vials
Nasal spray: 200 IU/activation

Indications and dosages
 Paget’s bone disease (osteitis deformans). Adults: Initially, 100 IU calcitonin S.C. or I.M. daily. Maintenance dosage is 50 to 100 IU calcitonin, three times weekly.
 Hypercalcemia. Adults: 4 IU/kg calcitonin (salmon) I.M. or S.C. q 12 hours; if no response in 1 to 2 days, increase to 8 IU/kg q 12 hours; if no response in 2 more days, increase to maximum of 8 IU/kg every 6 hours. Or, 2 to 16 IU/kg I.V. infusion ◇ q 12 hours.
 Postmenopausal osteoporosis. Adults: 100 IU calcitonin S.C. or I.M. daily, or 200 IU (one spray) daily in alternating nostrils.
 Osteogenesis imperfecta ◇. Adults: 2 IU/kg calcitonin I.M. or S.C. three times weekly, with daily P.O. calcium supplementation.

Pharmacodynamics
Hypocalcemic action: Calcitonin directly inhibits the bone resorption of calcium. This effect is mediated by drug-induced increase of cAMP level in bone cells, which alters transport of calcium and phosphate across the plasma membrane of the osteoclast. A secondary effect occurs in the kidneys, where calcitonin directly inhibits tubular resorption of calcium, phosphate, and sodium, thereby increasing their excretion. A clinical effect may not be seen for several months in patients with Paget’s disease.

Pharmacokinetics
Absorption: Plasma levels of 0.1 to 0.4 mg/ml are achieved within 15 minutes of a 200-IU S.C. dose. The maximum effect is seen in 2 to 4 hours.
Distribution: Not known.
Metabolism: Rapid metabolism occurs in the kidneys, with additional activity in the blood and peripheral tissues.
Excretion: Excreted in urine as inactive metabolites.

Contraindications and precautions
Contraindicated in patients hypersensitive to salmon calcitonin.

Interactions
None reported.

Adverse reactions
CNS: headache, weakness, dizziness, paresthesia.
CV: edema of feet, chest pressure, shortness of breath.
EENT: eye pain, nasal congestion.
GI: transient nausea, unusual taste, diarrhea, anorexia, vomiting, epigastric discomfort, abdominal pain.
GU: increased urinary frequency, nocturia.
Skin: facial flushing, rash, pruritus of ear lobes, inflammation at injection site.
Other: hypersensitivity reactions (anaphylaxis), tender palms and soles, chills.

Effects on lab test results
None reported.

Overdose and treatment
Signs and symptoms of overdose include hypocalcemia and hypocalcemic tetany. This usually occurs in patients at higher risk during the first few doses.
 Parenteral calcium will correct the symptoms and should be readily available.

Special considerations
• Preferred route is S.C.
 ALERT Prescribing, dispensing, and dosing errors have been reported using the abbreviation IU. Take care to write clearly or spell out if possible.
• Keep parenteral calcium available during the first doses in case of hypocalcemic tetany.
• Refrigerate solution. Once activated, nasal spray should be stored upright at room temperature.
• Consider a skin test using salmon calcitonin before starting therapy. If patient has allergic reactions to foreign proteins, test for hypersensitivity before therapy. Systemic allergic reactions are possible because hormone is a protein. Keep epinephrine readily available.
• Periodically monitor serum calcium levels during therapy.
• Observe patient for signs of hypocalcemic tetany during therapy (muscle twitching, tetanic spasms, and seizures if hypocalcemia is severe).
• Watch for evidence of hypercalcemic relapse: Bone pain, renal calculi, polyuria, anorexia, nausea, vomiting, thirst, constipation, lethargy, bradycardia, muscle hypotonicity, pathologic fracture, psychosis, and coma. Patient with good initial clinical response to calcitonin who suffers relapse should be evaluated for antibody formation response to the hormone protein.
• Perform periodic nasal examination in patients using nasal spray.
Pregnant patients
• Use drug cautiously.
Breast-feeding patients
• Use drug cautiously.
Pediatric patients
• There are inadequate data to support the use of calcitonin in children.

Patient education
• Teach patient how to administer drug, and assist him until he learns proper technique.
• Tell patient to handle missed doses as follows: For daily dosing, take as soon as possible, and don’t double the dose. For alternate day dosing, take as soon as possible, and then restart the alternate day schedule from this dose.
• Stress the importance of regular follow-up to assess progress.
• If given for postmenopausal osteoporosis, remind patient to take adequate calcium and vitamin D supplements.
• Instruct patient using the nasal spray to activate pump before using.
• Tell patient to report nasal irritation.

Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE THREATENING.
◆ Canada only
◇ Unlabeled clinical use