Parathyroid Hormone Analogue (Anabolic Bone Agent) Pregnancy: Contraindicated — risk of fetal skeletal effects

Teriparatide

Brand names: Forsteo

Adult dose

Dose: 20 mcg SC once daily

Route: Subcutaneous injection (thigh or abdomen)

Frequency: Once daily

Max: 20 mcg OD; maximum treatment duration 24 months (lifetime)

For severe osteoporosis with fractures or at very high fracture risk. Stimulates new bone formation (anabolic). Only 24 months lifetime treatment — follow with antiresorptive agent (bisphosphonate) to maintain gains.

Paediatric dose

Route: N/A

Frequency: N/A

Max: Not licensed in children or adolescents

Not established — open epiphyses are a contraindication due to risk of osteosarcoma (based on animal data)

Dose adjustments

Renal

Avoid if eGFR <30

Hepatic

No specific dose adjustment

Clinical pearls

Anabolic vs antiresorptive: teriparatide actually builds new bone (increases BMD more than bisphosphonates in trabecular bone)
NICE TA161: teriparatide for very severe osteoporosis (T-score ≤−4 or ≤−3.5 with ≥2 falls/fractures, unable to tolerate bisphosphonates)
Osteosarcoma black box (FDA): theoretical based on rat studies; no confirmed cases in humans — benefit-risk favourable in severe osteoporosis
First injection: dizziness and hypotension common — give seated, observe 30 min

Contraindications

Pre-existing hypercalcaemia
Metabolic bone disease other than osteoporosis (Paget's disease, hyperparathyroidism, unexplained elevated ALP)
Prior radiation to the skeleton
Malignancy or skeletal metastases
Open epiphyses (children/adolescents)
Pregnancy

Side effects

Hypercalcaemia (check serum calcium at 1 month)
Nausea
Dizziness
Leg cramps
Hypotension (especially on first injection — observe for 30 min)
Osteosarcoma (rare — black box warning based on rat data; no confirmed human cases in 20+ years post-marketing)

Interactions

Digoxin — hypercalcaemia may increase digoxin toxicity

Monitoring

Serum calcium (1 month after starting; then periodically)
BMD (DEXA at 18 months, then post-treatment)
Urinary calcium/creatinine ratio (hypercalciuria monitoring)
ALP if unexpectedly elevated

Reference: BNFc; BNF; NICE TA161; FRAX Fracture Risk Assessment; Lilly Forsteo SPC. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways