Calcitonin Flashcards
What class does Calcitonin belong to?
agents affecting calcium and bone metabolism
What are examples of other drugs in the same class as Calcitonin?
parathyroid hormone
teriparatide
What is calcitonin indicated for?
Used to lower plasma Ca concentrations in patients with hypercalcaemia associated with malignancy.
Treatment of Paget’s disease of bone when other treatments are ineffective/inappropriate
For the prevention/treatment of postmenopausal osteoporosis if beneifits outweigh risks of malignancy assoc. with long term use.
For OP vertebral compression fracture associated bone pain.
Neurological complications
What is the dose of calcitonin used in osteoporosis?
For acute bone pain: 100-200 IU/day by SC or IM in divided doses OR slow IV infusion (in physiological saline); continue until satisfactory response; usual duration is less than 4 weeks.
What is Calcitonin?
Calcitonin is involved with parathyroid hormone in the regulation of bone turnover, and hence in the maintenance of calcium balance and homeostasis.
It increases bone mass and bone mineral density and decreases bone resorption.
What is the mechanism of action of Calcitonin?
Calcitonin binds to the calcitonin receptor which is found primarily in osteoclasts. This enhances the production of vitamin D producing enzymes (25-hydroxyvitamine D-24-hydroxylase), leading to greater calcium retention and enhanced bone density. Binding of calcitonin to its receptor also activates adenylyl cyclase and the phosphatidyl-inositol-calcium pathway.
Calcitonin is a powerful inhibitor of osteoclasts, and has opiate-mediated analgesic properties.
What are the characteristic pharmacokinetic/pharmacodynamic parameters of Calcitonin?
Absolute F ~70% afiter IM or SC
Apparent VD = 0.15-0.3L/kg
Protein binding ~ 30-40%
Elimination half life ~1 hour for IM and 1-1.5 hours for SC
Metabolites are 95% excreted by the kidney
What is the role of Calcitonin in Osteoporosis therapy?
secondary line after bisphophonates do not work.
It is used as treatment for bone pain if paracetamol, NSAIDs and low dose opioid are not sufficient.
It is quite expensive ($110.00, MIMS)
What are the precautions with Calcitonin use?
history of allergy, heart failure, prolonged use is associated with risk of malignancy,
ensure patient has adequate Ca and Vitamin D intake.
Pregnancy Category B2: avoid unless benefit outweighs risk.
Avoid in breast feeding - inhibits lactation.
Take caution in renal impairment
What are the contraindications of Calcitonin use?
hypocalcaemia
What are the adverse effects associated with calcitonin use?
nausea, vomiting, diarrhoea
abdrominal pain, taste disturbances, flushing
dizziness, headache, fatigue, malignancy, musculoskeletal pain.
What are the drug interactions associated with calcitonin use?
Lithium: monitor for adverse effects of lithium (trmor, dysarthria, ataxia, confusion) consider monitoring lithium levels if interaction is suspected.
What are the alarm bells associated with calcitonin use
highly advised to have a skin test to determine allergy to calcitonin salmon.
use the lowest effective dose of calcitonin for the shortest possible time to decrease malignancy risk.
