Dosing and uses of Forteo, parathyroid hormone (teriparatide)
Adult dosage forms and strengths
prefilled injectable pen
- 600mcg/mL (2.4mL)
Osteoporosis
Treatment of postmenopausal women with osteoporosis at high risk for fracture; increase of bone mass in men with primary or hypogonadal osteoporosis at high risk for fracture; treatment of men and women with osteoporosis associated with sustained systemic glucocorticoid therapy at high risk for fracture
Administer initially while patient is sitting or lying down in the event of orthostasis
20 mcg SC once daily into thigh or abdominal walL
Dosing Modifications
CrCl <30 mL/min: Dose adjustment not necessary; bioavailability and half-life may increase
Osteoporosis (Orphan)
Orphan designation for treatment of idiopathic osteoporosis
Orphan indication sponsor
- Biomeasure, Inc; 27 Maple St; Milford, MA 01757-3650
Hypoparathyroidism (Orphan)
Orphan designation for treatment of hypoparathyroidism
Orphan sponsor
- Entera Bio, Ltd; Kiryat Hadassah Minrav Bldg, 5th Floor, P. O. Box 12117; Jeusalem 91220, Israel
Pediatric dosage forms and strengths
Safety and efficacy not established
Forteo, parathyroid hormone (teriparatide) adverse (side) effects
>10%
Hypercalcemia (transient increases 4-6 hours after dose; 11% of women, 6% of men)
1-10%
Arthralgia (10%)
Rhinitis (10%)
Nausea (9%)
Weakness (9%)
Dizziness (8%)
Pharyngitis (6%)
Dyspepsia (5%)
Rash (5%)
Depression (4%)
Dyspnea (4%)
Pneumonia (4%)
Vertigo (4%)
Antibodies to teriparatide (3% of women in long-term treatment)
Chest pain (3%)
Hyperuricemia (3%)
Leg cramps (3%)
Syncope (3%)
Vomiting (3%)
Tooth disorder (2%)
Warnings
Black box warnings
In rats, increased risk of osteosarcoma has been observed; do not prescribe for patients at high risk for osteosarcoma (eg, those with Paget disease, unexplained alkaline phosphatase elevation, open epiphyses, or previous external-beam or implant radiation therapy involving skeleton)
Contraindications
Hypersensitivity
High risk for osteosarcoma
Cautions
Hypercalcemia may predispose to digoxin toxicity
Orthostatic hypotension may occur
Urolithiasis, bone metastases, metabolic bone disease (other than osteoporosis), open epiphyses, Paget disease, preexisting hypercalcemia
Use of drug for >2 years during patient lifetime not recommended
Use caution in cardiovascular disease, renal and/or hepatic impairment, and patients with active or recent urolithiasis
Pregnancy and lactation
Pregnancy category: C
Lactation: Safe
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Forteo, parathyroid hormone (teriparatide)
Mechanism of action
Recombinant human parathyroid hormone; stimulates osteoblast function, increases calcium absorption, and increases renal tubular reabsorption of calcium; these effects lead to increased bond mineral density, bone mass, and strength
Absorption
Bioavailability: 95%
Onset: 3 months
Peak serum time: Teriparatide, 30 min; calcium, 4-6 hr
Concentration: Calcium, 9.68 mg/dL
Distribution
Vd: 0.12 L/kg
Elimination
Half-life: 5 min (IV); 1 hr (SC)
Total body clearance: Women, 62 L/hr; men, 94 L/hr
Excretion: Urine
