Teriparatide
Parathyroid hormone (PTH) analogues
Parathyroid hormone (PTH) analoguesPregnancy: avoid
Not used in pregnancy or breastfeeding; it is meant for postmenopausal women and men.
The first 34 amino acids of human parathyroid hormone, injected once a day to build new bone in severe osteoporosis.
Also called: Recombinant human PTH (1-34)
Quick facts
- Group
- Parathyroid hormone (PTH) analogues
- Target
- PTH/PTHrP type 1 receptor (PTH1R), a G-protein–coupled receptor
- Used for
- Reduction of vertebral · Osteoporosis in men
- Key effects
- Nausea · Leg cramps and joint pain · Headache
- Monitor
- Serum calcium as ordered · Blood pressure
- ATC
- H05AA02
No doses: the clinician sets them by the current guideline.
Mechanism of action
The figure shows teriparatide itself (a peptide chain) bound to the human PTH1 receptor with its Gs protein; as a peptide, it has no small-molecule ligand code.
Teriparatide is recombinant PTH(1-34), the active part of the hormone. It binds the PTH1 receptor on osteoblasts and kidney cells. Given once daily it produces a short peak that stimulates osteoblasts more than osteoclasts, so formation exceeds resorption, bone mass rises and vertebral and other fractures fall. In the kidney it increases calcium reabsorption and phosphate excretion, which can raise serum calcium for a few hours.
- A daily injection gives a short peak of PTH(1-34)
- It activates the PTH1 receptor on osteoblasts
- Osteoblasts multiply and lay down new bone
- Bone mass rises and fractures fall
Indications
- Postmenopausal osteoporosis at high fracture risk Osteoporosis →
- Reduction of vertebral and non-vertebral fractures Osteoporotic vertebral compression fracture →
- Osteoporosis in men and glucocorticoid-induced osteoporosis at high fracture risk
Adverse effects
Common
- Dizziness and orthostatic hypotension after the first doses
- Nausea, heartburn
- Leg cramps and joint pain
- Injection-site redness, pain or bruising
- Headache
Contraindications
- Hypersensitivity to teriparatide
- Avoided in Paget disease, open epiphyses and previous skeletal radiation
- Avoided with bone cancer or metastases to bone
- Avoided in hypercalcaemic disorders (e.g. primary hyperparathyroidism)
- Not used in pregnancy
Key interactions
- Digoxin
- The transient rise in calcium can make digoxin toxicity more likely
What is monitored
- Serum calcium as ordered
- Blood pressure and dizziness after the first doses
- Kidney stones or urinary symptoms
- Cumulative time on treatment
- Skin lesions in calciphylaxis
Administration and safety
- Subcutaneous injection once a day into the thigh or abdomen, rotating sites; never into a vein or muscle
- The pen is used only by the person it was prescribed for and the drug is not moved to a syringe; a new needle each time
- The first doses are given where the person can sit or lie down at once
- Use beyond two years in a lifetime is considered only if fracture risk stays high
Pregnancy and breastfeeding
Not used in pregnancy or breastfeeding; it is meant for postmenopausal women and men.
Nursing care
- Teach injection technique, site rotation and needle disposal
- Teach to rise slowly and sit or lie down if dizzy or the heart races after a dose
- Teach signs of high calcium: nausea, vomiting, constipation, weakness, fatigue
- Ask about Paget disease, bone radiation, bone cancer and kidney stones before starting
- Check digoxin use and watch for its toxicity
Pharmacokinetics
- Absorption
- Subcutaneous, with high bioavailability
- Metabolism
- Broken down by peptidases, believed to be mainly in the liver
- Elimination
- Fragments are cleared by the kidney
- Half-life
- About one hour after a subcutaneous injection
Test yourself
Think of the answer, then tap the question to see it.
Why are the first doses of teriparatide given with the person sitting or lying down?
It can cause transient orthostatic hypotension, with dizziness, palpitations or fainting, in the hours after early doses.
Which drug interaction is flagged in the teriparatide label?
Digoxin: teriparatide raises serum calcium transiently, which can bring on digitalis toxicity.
In which two situations, for example, is teriparatide avoided?
Any two of: Paget disease, open epiphyses, previous skeletal radiation, bone cancer or metastases, hypercalcaemic disorders, pregnancy.
Connections
← Back to the class: Parathyroid hormone (PTH) analogues
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Teriparatide Injection: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2026); DailyMed - TERIPARATIDE injection (DailyMed (U.S. National Library of Medicine), 2026); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026).
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Representative model, for educational purposes only.