MIACALCIN
Clinical safety rating: caution
Comprehensive clinical and safety monograph for MIACALCIN (MIACALCIN).
Synthetic salmon calcitonin binds to calcitonin receptors on osteoclasts, inhibiting osteoclast activity and reducing bone resorption. It also increases renal excretion of calcium and phosphate and has analgesic effects in bone pain, possibly via central modulation of pain perception.
| Metabolism | Primarily metabolized via peptidases in the kidney and liver; small amounts excreted unchanged in urine. No specific cytochrome P450 involvement. |
| Excretion | Renal excretion of intact drug and metabolites; 95% of radiolabeled dose recovered in urine, <2% in feces. |
| Half-life | Terminal half-life after intravenous administration is approximately 1.2 hours; with intramuscular or subcutaneous administration, half-life is prolonged to 1.4–2.0 hours due to absorption rate-limited elimination. |
| Protein binding | 30–40% bound to plasma proteins (mainly albumin). |
| Volume of Distribution | 0.15–0.30 L/kg; distributes primarily into extracellular fluid and bone. |
| Bioavailability | Intramuscular: 66%; subcutaneous: 50–65%; intranasal: 3–5% relative to intramuscular injection. |
| Onset of Action | Intravenous: <15 minutes; intramuscular: 15–30 minutes; subcutaneous: 30–60 minutes. |
| Duration of Action | Intravenous: 2–6 hours (calcium-lowering effect); intramuscular/subcutaneous: 6–8 hours (effect on bone turnover lasts up to 12 hours with repeated dosing). |
For osteoporosis: 200 IU (0.5 mL) intranasally once daily, alternating nostrils daily. For Paget disease: 100 IU (0.5 mL) subcutaneously or intramuscularly once daily. For hypercalcemia: 4 IU/kg subcutaneously or intramuscularly every 12 hours; may increase to 8 IU/kg every 12 hours if no response after 2 days.
| Dosage form | INJECTABLE |
| Renal impairment | No specific dose adjustment provided by manufacturer; caution in renal impairment due to potential accumulation. GFR <30 mL/min: use with monitoring. |
| Liver impairment | No specific adjustment required for hepatic impairment as calcitonin is primarily metabolized by kidneys. |
| Pediatric use | Not approved for use in children; safety and efficacy not established. |
| Geriatric use | No specific dose adjustment required; but monitor renal function in elderly due to age-related decline. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for MIACALCIN (MIACALCIN).
| Breastfeeding | Calcitonin is secreted into human milk at low levels. The milk-to-plasma ratio (M/P) has not been established for salmon calcitonin. Due to limited data, caution is advised. Effects on nursing infants are unknown; consider developmental and health benefits of breastfeeding along with mother's clinical need for Miacalcin. |
| Teratogenic Risk | Calcitonin-salmon (Miacalcin) is classified as FDA Pregnancy Category C. Animal studies have shown embryocidal effects and decreased fetal birth weights at doses 14-56 times the human dose. No adequate and well-controlled studies in pregnant women. Risk cannot be ruled out; use only if potential benefit justifies potential risk to fetus. Specific trimester risks are not well-characterized but placental transfer is limited due to high molecular weight. |
■ FDA Black Box Warning
None
| Serious Effects |
Hypersensitivity to salmon calcitonin or any formulation component; hypocalcemia; (relative) severe renal impairment (creatinine clearance <15 mL/min) due to increased risk of adverse effects.
| Precautions | Allergic reactions (including anaphylaxis, bronchospasm, urticaria); risk of hypersensitivity, especially in patients with prior exposure; nasal spray may cause rhinitis, epistaxis, or ulceration of nasal mucosa; hypocalcemia risk, especially in patients with low serum calcium or renal impairment; anti-calcitonin antibodies may develop with chronic use, potentially reducing efficacy; dermal application site reactions (for injectable forms). |
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| Fetal Monitoring | Monitor serum calcium, phosphate, and magnesium levels periodically. Assess renal function due to possible electrolyte disturbances. Observe for signs of hypersensitivity reactions (urticaria, bronchospasm, anaphylaxis). In pregnancy, monitor fetal growth and development via ultrasound due to animal reproductive findings. |
| Fertility Effects | No human studies on fertility. Animal studies have not demonstrated adverse effects on fertility. Theoretical disruption of calcium homeostasis could impact reproductive function, but specific data are lacking. |