calcitonin

calcitonin /cal·ci·to·nin/ (-to´nin) a polypeptide hormone secreted by C cells of the thyroid gland, and sometimes of the thymus and parathyroids, which lowers calcium and phosphate concentration in plasma and inhibits bone resorption. Preparations (c.-human, c.-salmon) are used in the treatment of osteitis deformans, postmenopausal osteoporosis, and hypercalcemia.

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cal·ci·to·nin (kls-tnn)

n.

A peptide hormone, produced by the thyroid gland in humans, that acts to lower plasma calcium and phosphate levels without augmenting calcium accretion. Also called thyrocalcitonin.

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Calcitonin

A hormone produced by the parafollicular cells (C cells) of the thyroid. The main function of the hormone is to regulate calcium levels in body serum.

Mentioned in: Hypoparathyroidism, Osteoporosis, Paget's Disease of Bone, Thyroid Cancer

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calcitonin

[kal′sitō′nin]

Etymology: L, calx + Gk, tonos, tone

a hormone produced in parafollicular cells of the thyroid that participates in regulating the blood level of calcium and stimulates bone mineralization. A synthetic preparation of the hormone is used in the treatment of certain bone disorders. Calcitonin acts to reduce the blood level of calcium and to inhibit bone resorption, whereas parathyroid hormone acts to increase blood calcium level and bone resorption. Vitamin D also contributes to the regulation of calcium homeostasis. Also called salmon calcitonin, thyrocalcitonin.

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calcitonin (kal·si·tōˑ·nin),

n hormone originating in the thyroid's parafollicular cells; plays a role in calcium blood level regulation and serves to stimulate bone mineralization.

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calcitonin (kal´sitō´nin),

n brand names: Calcitonin, Calcimar, Miacalcin;
drug class: synthetic polypeptide calcitonins;
action: inhibits bone resorption, reduces osteoclast function, reduces serum calcium levels in hypercalcemia;
uses: Paget's disease, postmenopausal osteoporosis, hypercalcemia.

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calcitonin

a polypeptide hormone secreted by the parafollicular or C cells of the thyroid gland, which is involved in plasma calcium homeostasis. It acts to decrease the rate of bone resorption. Called also thyrocalcitonin.

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calcitonin gene-related peptides

potent vasodilators widely distributed in periadventitial nerves of blood vessels, sinoatrial and atrioventricular nodes, sensory neurons and the central nervous system generally.

calcitonin-secreting cells

parafollicular cells of the thyroid gland.

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calcitonin (human)

Cibacalcin

Pharmacologic class: Hormone (calcium-lowering)

Therapeutic class: Hypocalcemic

Pregnancy risk category C

Action

Directly affects bone, kidney, and GI tract. Decreases osteoclastic osteolysis in bone; also reduces mineral release and collagen breakdown in bone and promotes renal excretion of calcium. In pain relief, acts through prostaglandin inhibition, pain threshold modification, or beta-endorphin stimulation.

Availability

Injection: 0.5 mg/ml (human), 1 mg/ml (human), 200 international units/ml in 2-ml vials (salmon)

Nasal spray (salmon): 200 international units/actuation, metered nasal spray in 3.7 ml-bottle

⊘Indications and dosages

➣ Postmenopausal osteoporosis

Adults: Calcitonin (salmon) - 100 international units/day I.M. or subcutaneously, or 200 international units/day intranasally with concurrent supplemental calcium and vitamin D

➣ Paget's disease of bone (osteitis deformans)

Adults: Calcitonin (salmon) - Initially, 100 international units/day I.M. or subcutaneously; after titration, maintenance dosage is 50 to 100 international units daily or every other day (three times weekly). Calcitonin (human) - 0.5 mg I.M. or subcutaneously daily, reduced to 0.25 mg daily.

➣ Hypercalcemia

Adults: Calcitonin (salmon) - 4 international units/kg I.M. or subcutaneously q 12 hours; after 1 or 2 days, may increase to 8 international units/kg q 12 hours; after 2 more days, may increase further, if needed, to 8 international units q 6 hours.

Contraindications

• Hypersensitivity to drug or salmon
• Pregnancy or breastfeeding

Precautions

Use cautiously in:
• renal insufficiency, pernicious anemia
• children.

Administration

☞ Before salmon calcitonin therapy begins, perform skin test, if ordered.
• Bring nasal spray to room temperature before using.
• Give intranasal dose as one spray in one nostril daily; alternate nostrils every day.
• To minimize adverse effects, give at bedtime.
• Rotate injection sites to decrease inflammatory reactions.

Route	Onset	Peak	Duration
I.M., subcut.	15 min	4 hr	8-24 hr
Intranasal	Rapid	0.5 hr	1 hr

Adverse reactions

CNS: headache, weakness, dizziness, paresthesia

CV: chest pain

EENT: epistaxis, nasal irritation, rhinitis

GI: nausea, vomiting, diarrhea, epigastric pain or discomfort

GU: urinary frequency

Musculoskeletal: arthralgia, back pain

Respiratory: dyspnea

Skin: rash

Other: altered taste, allergic reactions including facial flushing, swelling, and anaphylaxis

Interactions

Drug-drug. Previous use of bisphosphonates (alendronate, etidronate, pamidronate, risedronate): decreased response to calcitonin

Patient monitoring

• Monitor for adverse reactions during first few days of therapy.
• Assess alkaline phosphatase level and 24-hour urinary excretion of hydroxyproline.
• Check urine for casts.
• Monitor serum electrolyte and calcium levels.

Patient teaching

• Instruct patient to take drug before bedtime to lessen GI upset. Tell him to call prescriber if he can't maintain his usual diet because of GI upset.
• Inform patient using nasal spray that runny nose, sneezing, and nasal irritation may occur during first several days as he adjusts to spray.
• Instruct patient to bring nasal spray to room temperature before using.
• Advise patient to blow nose before using spray, to take intranasal dose as one spray in one nostril daily, and to alternate nostrils with each dose.
• Tell patient to discard unrefrigerated bottles of calcitonin (salmon) nasal spray after 30 days.
• Encourage patient to consume a diet rich in calcium and vitamin D.
• As appropriate, review all other significant adverse reactions and interactions, especially those related to the drugs mentioned above.

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calcitonin (salmon)

Calcimar, Caltine, Fortical, Miacalcic (UK), Miacalcin, Miacalcin Nasal Spray, Salmonine

Pharmacologic class: Hormone (calcium-lowering)

Therapeutic class: Hypocalcemic

Pregnancy risk category C

Action

Directly affects bone, kidney, and GI tract. Decreases osteoclastic osteolysis in bone; also reduces mineral release and collagen breakdown in bone and promotes renal excretion of calcium. In pain relief, acts through prostaglandin inhibition, pain threshold modification, or beta-endorphin stimulation.

Availability

Injection: 0.5 mg/ml (human), 1 mg/ml (human), 200 international units/ml in 2-ml vials (salmon)

Nasal spray (salmon): 200 international units/actuation, metered nasal spray in 3.7 ml-bottle

⊘Indications and dosages

➣ Postmenopausal osteoporosis

Adults: Calcitonin (salmon) - 100 international units/day I.M. or subcutaneously, or 200 international units/day intranasally with concurrent supplemental calcium and vitamin D

➣ Paget's disease of bone (osteitis deformans)

Adults: Calcitonin (salmon) - Initially, 100 international units/day I.M. or subcutaneously; after titration, maintenance dosage is 50 to 100 international units daily or every other day (three times weekly). Calcitonin (human) - 0.5 mg I.M. or subcutaneously daily, reduced to 0.25 mg daily.

➣ Hypercalcemia

Adults: Calcitonin (salmon) - 4 international units/kg I.M. or subcutaneously q 12 hours; after 1 or 2 days, may increase to 8 international units/kg q 12 hours; after 2 more days, may increase further, if needed, to 8 international units q 6 hours.

Contraindications

• Hypersensitivity to drug or salmon
• Pregnancy or breastfeeding

Precautions

Use cautiously in:
• renal insufficiency, pernicious anemia
• children.

Administration

☞ Before salmon calcitonin therapy begins, perform skin test, if ordered.
• Bring nasal spray to room temperature before using.
• Give intranasal dose as one spray in one nostril daily; alternate nostrils every day.
• To minimize adverse effects, give at bedtime.
• Rotate injection sites to decrease inflammatory reactions.

Route	Onset	Peak	Duration
I.M., subcut.	15 min	4 hr	8-24 hr
Intranasal	Rapid	0.5 hr	1 hr

Adverse reactions

CNS: headache, weakness, dizziness, paresthesia

CV: chest pain

EENT: epistaxis, nasal irritation, rhinitis

GI: nausea, vomiting, diarrhea, epigastric pain or discomfort

GU: urinary frequency

Musculoskeletal: arthralgia, back pain

Respiratory: dyspnea

Skin: rash

Other: altered taste, allergic reactions including facial flushing, swelling, and anaphylaxis

Interactions

Drug-drug. Previous use of bisphosphonates (alendronate, etidronate, pamidronate, risedronate): decreased response to calcitonin

Patient monitoring

• Monitor for adverse reactions during first few days of therapy.
• Assess alkaline phosphatase level and 24-hour urinary excretion of hydroxyproline.
• Check urine for casts.
• Monitor serum electrolyte and calcium levels.

Patient teaching

• Instruct patient to take drug before bedtime to lessen GI upset. Tell him to call prescriber if he can't maintain his usual diet because of GI upset.
• Inform patient using nasal spray that runny nose, sneezing, and nasal irritation may occur during first several days as he adjusts to spray.
• Instruct patient to bring nasal spray to room temperature before using.
• Advise patient to blow nose before using spray, to take intranasal dose as one spray in one nostril daily, and to alternate nostrils with each dose.
• Tell patient to discard unrefrigerated bottles of calcitonin (salmon) nasal spray after 30 days.
• Encourage patient to consume a diet rich in calcium and vitamin D.
• As appropriate, review all other significant adverse reactions and interactions, especially those related to the drugs mentioned above.

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calcitonin

Thyrocalcitonin Physiology A 32 residue polypeptide–plasma levels 100 pg/mL hormone produced by the parafollicular or 'C'–ultimobranchial cells of the thyroid; calcitonin is rapidly secreted in response to ↑ plasma Ca2+, pentagastrin, glucagon, β-adrenergics, and alcohol; it is produced by several neoplasms, especially, medullary CA of thyroid–MCT, which may also be associated with other endocrine tumors ↑ in MCT, small cell of the lung, breast CA. See C cells.