CALCITONIN-SALMON
Clinical safety rating: safe
Animal studies have demonstrated safety
Synthetic polypeptide analog of salmon calcitonin that inhibits osteoclastic bone resorption, increases renal excretion of calcium and phosphate, and reduces serum calcium via direct action on osteoclast calcitonin receptors.
| Metabolism | Primarily metabolized via proteolysis in the kidneys, liver, and blood; excreted as inactive metabolites in urine. |
| Excretion | Primarily metabolized in the kidneys, with 95% of the dose excreted as inactive metabolites in urine; less than 2% excreted unchanged in feces. |
| Half-life | Terminal elimination half-life is 1.2 hours for subcutaneous and intramuscular routes; clinical effect persists longer due to prolonged receptor binding. |
| Protein binding | 30-40%, primarily to albumin. |
| Volume of Distribution | 0.3-0.4 L/kg, indicating distribution primarily into extracellular fluid. |
| Bioavailability | Subcutaneous: 71%; Intramuscular: 66%; Intranasal: 3%. |
| Onset of Action | Subcutaneous: 15 minutes; Intramuscular: 15 minutes; Intranasal: 30 minutes; Intravenous: immediate. |
| Duration of Action | Subcutaneous/Intramuscular: 8-12 hours; Intranasal: 6-8 hours; Intravenous: 2-4 hours. |
100 IU subcutaneously or intramuscularly once daily for osteoporosis; 4 IU/kg subcutaneously or intramuscularly every 12 hours for Paget's disease; 4 IU/kg subcutaneously or intramuscularly every 12 hours for hypercalcemia.
| Dosage form | INJECTABLE |
| Renal impairment | CrCl <30 mL/min: reduce dose by 50%; CrCl <15 mL/min: avoid use. |
| Liver impairment | No adjustment required for mild to moderate hepatic impairment (Child-Pugh A or B); Child-Pugh C: use with caution. |
| Pediatric use | Not established; use not recommended. |
| Geriatric use | No specific adjustment; monitor for renal function and electrolyte disturbances. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
No significant drug interactions Potential for serious allergic reactions including anaphylaxis.
| Breastfeeding | Calcitonin is present in human milk at low concentrations. M/P ratio not established. Oral bioavailability in infants is negligible due to protein digestion. Use with caution in nursing mothers, although likely safe given minimal absorption. Observe infant for signs of hypocalcemia. |
| Teratogenic Risk | Pregnancy Category C. Salmon calcitonin does not cross the placenta in significant amounts. Animal studies have shown embryocidal effects and reduced fetal birth weights at high doses. No adequate human studies exist. Risk cannot be ruled out; use only if clearly needed. Potential risks to fetus in all trimesters include hypocalcemia due to maternal calcitonin administration. |
■ FDA Black Box Warning
None.
| Common Effects | osteoporosis |
| Serious Effects |
["Hypersensitivity to salmon calcitonin or any component of the formulation","Hypocalcemia (absolute)"]
| Precautions | ["Hypersensitivity reactions (rare, including anaphylaxis, bronchospasm, urticaria)","Hypocalcemia risk (especially with high doses or prolonged use)","Nasal ulceration (with intranasal formulation; periodic exam recommended)","Malignancy risk (theoretical; long-term use associated with increased cancer incidence in some studies; not confirmed)","Antibody formation (may reduce efficacy)"] |
| Food/Dietary | Calcium-rich foods or supplements may reduce absorption; separate by at least 2 hours. No other significant food interactions. |
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| Fetal Monitoring | Monitor maternal serum calcium during therapy, especially if used for hypercalcemia or Paget disease. For prolonged use, monitor bone mineral density and renal function. In pregnancy, monitor fetal growth and development via ultrasound if prolonged use. |
| Fertility Effects | In animal studies, high doses of salmon calcitonin have been associated with decreased fertility and impaired implantation. No human data. Theoretical effect due to calcium regulation disturbances. Use during attempts to conceive only if clearly necessary. |
| Clinical Pearls | Monitor for hypersensitivity reactions, especially in patients with allergies to fish. Nasal spray may cause rhinitis and epistaxis. Use with caution in patients with hypocalcemia or renal impairment. Efficacy may diminish with prolonged use due to antibody formation. |
| Patient Advice | Report signs of allergy such as rash, hives, difficulty breathing, or swelling of face/throat immediately. · For nasal spray: alternate nostrils daily; do not sniff deeply after administration. · Avoid taking calcium supplements within 2 hours of calcitonin to ensure absorption. · Calcitonin may cause nausea, vomiting, or flushing; take at bedtime to minimize these effects. · Store calcitonin injection in refrigerator; nasal spray at room temperature. · Do not discontinue abruptly without consulting your doctor. |