Parathyroid Hormone (PTH)

Endocrine & Metabolic

Mark this drug class

Examples

teriparatide (Forteo)abaloparatide (Tymlos)

Prefix / Suffix: -paratide

Physiology

Parathyroid hormone (PTH) regulates calcium. Continuous high PTH causes bone loss; intermittent low-dose PTH stimulates bone formation.

Mechanism of Action

Synthetic PTH (1-34) — when given as daily injection, stimulates osteoblast activity and new bone formation (anabolic effect).

Indications

Severe osteoporosis at high fracture risk
Glucocorticoid-induced osteoporosis
Failure or intolerance of bisphosphonates

Side Effects / Adverse Effects

Orthostatic hypotension (especially after first dose)
Nausea, dizziness
Leg cramps
Hypercalcemia
Osteosarcoma in animal studies (black box — limit to 2 years lifetime)
Injection site reactions

Contraindications

Increased baseline risk of osteosarcoma (Paget's, prior radiation, unexplained alkaline phosphatase elevation)
Severe renal impairment
Hypercalcemia
Pregnancy

Nursing Considerations

Daily subcutaneous injection in thigh or abdomen
Give first dose with patient sitting/lying — orthostatic hypotension risk
Lifetime use limited to 2 years (osteosarcoma concern)
Rotate injection sites
Refrigerate pen; use within 28 days of first use
Follow with bisphosphonate after stopping to maintain bone gains
Ensure adequate calcium and vitamin D
Monitor serum and urine calcium

Ask PharmPal Nurse

Your AI tutor for Parathyroid Hormone (PTH)

Ask me anything about this drug class.

Disclaimer: PharmPal Nurse is for education only and is not medical advice. Do not use it to diagnose, treat, prescribe, or make patient-care decisions; always verify with current drug references, your instructor, facility policy, and a licensed provider. In emergencies, call local emergency services.