FORTEO

Clinical safety rating: caution

Comprehensive clinical and safety monograph for FORTEO (FORTEO).

How it works

Recombinant human parathyroid hormone analog (1-34) that stimulates osteoblast activity, increasing bone formation and turnover.

What the body does with it

Metabolism	Hepatically cleared via nonspecific proteolytic degradation; no significant cytochrome P450 involvement.
Excretion	Renal (metabolites, primarily via glomerular filtration and tubular secretion; ~95% of absorbed dose eliminated in urine within 24 hours). Biliary/fecal: minimal (< 2%).
Half-life	Terminal half-life: approximately 1 hour (subcutaneous administration). Clinically, the short half-life supports once-daily dosing; no accumulation observed with daily dosing.
Protein binding	Approximately 80% bound to plasma proteins (primarily albumin and alpha-2 macroglobulin).
Volume of Distribution	0.9–1.1 L/kg (distribution primarily to bone, kidney, and liver; reflects extensive tissue binding).
Bioavailability	Subcutaneous: approximately 95% (bioequivalent to subcutaneous injection). Intranasal: not applicable. Intravenous: not approved.
Onset of Action	Subcutaneous: Stimulation of bone formation within 1 hour (increase in serum bone-specific alkaline phosphatase and P1NP); initial increase in serum calcium noted at 4–6 hours.
Duration of Action	Duration of biochemical effect: up to 12–24 hours (elevated bone formation markers). Clinical effect on BMD requires continuous daily dosing for at least 12–18 months. Maximum approved treatment duration: 24 months.

Classification & Brands

Action Class	Bone formation stimulator -PTH analogue
Brand Substitutes	Gemtide Injection, Gemtide Injection (2.4ml Each), Oflotas 200mg Tablet, Olox 200mg Tablet, Oflamed 200 Tablet, Oxa 200mg Tablet, Zenflox 200 Tablet, Horn O 200mg/500mg Tablet, Orni-O Tablet, Oflotas-OZ Tablet, Zorno Tablet, Ornof Tablet, OWINO Z 50 MG/125 MG SUSPENSION, Oflokem OZ Suspension, Bacter OZ Suspension, Maxxo OZ Suspension, Sinox OZ Suspension

Dosing & administration

20 mcg subcutaneously once daily.

Dosage form	SOLUTION
Renal impairment	No dose adjustment required for mild to moderate renal impairment (CrCl 30-89 mL/min). Not recommended for severe renal impairment (CrCl <30 mL/min) due to limited data.
Liver impairment	No dose adjustment required for mild to moderate hepatic impairment (Child-Pugh class A or B). Not studied in severe hepatic impairment (Child-Pugh class C).
Pediatric use	Not indicated for pediatric patients (safety and efficacy not established).
Geriatric use	No dose adjustment based on age alone; consider renal function and comorbidities.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for FORTEO (FORTEO).

Breastfeeding	Excretion into human milk unknown; however, teriparatide is a peptide hormone and likely degraded in infant GI tract. Low oral bioavailability suggests minimal systemic exposure. Caution advised. M/P ratio not determined.
Teratogenic Risk	FORTEO (teriparatide) is a Pregnancy Category C drug. In animal studies, teriparatide caused increased fetal skeletal abnormalities and soft tissue anomalies at doses 2-194 times the human exposure. No adequate human studies exist. Risk cannot be ruled out; use only if potential benefit justifies potential risk to fetus, especially during first trimester.

Warnings & precautions

■ FDA Black Box Warning

Increased risk of osteosarcoma in rats; avoid use in patients with Paget disease, unexplained alkaline phosphatase elevation, pediatric populations, or prior radiation therapy to the skeleton.

Side Effect Profile

Serious Effects

Absolute Contraindications

["Paget disease of bone","Unexplained alkaline phosphatase elevation","Pediatric patients (open epiphyses)","Prior external beam or implant radiation to the skeleton","Bone metastases or history of skeletal malignancies","Hypercalcemia or pre-existing hypercalcemic disorders (e.g., hyperparathyroidism)","Pregnancy and lactation"]

Clinical Precautions

Precautions

["Risk of osteosarcoma (black box)","May cause hypercalcemia and hypercalciuria","Orthostatic hypotension may occur within 4 hours of dosing","Use caution in patients with active urolithiasis","Duration of treatment should not exceed 2 years"]

Clinical Tips & Counseling

Drug interactions

Loading safety data…

FORTEO

Clinical safety rating: caution

Comprehensive clinical and safety monograph for FORTEO (FORTEO).

How it works

Recombinant human parathyroid hormone analog (1-34) that stimulates osteoblast activity, increasing bone formation and turnover.

What the body does with it

Metabolism	Hepatically cleared via nonspecific proteolytic degradation; no significant cytochrome P450 involvement.
Excretion	Renal (metabolites, primarily via glomerular filtration and tubular secretion; ~95% of absorbed dose eliminated in urine within 24 hours). Biliary/fecal: minimal (< 2%).
Half-life	Terminal half-life: approximately 1 hour (subcutaneous administration). Clinically, the short half-life supports once-daily dosing; no accumulation observed with daily dosing.
Protein binding	Approximately 80% bound to plasma proteins (primarily albumin and alpha-2 macroglobulin).
Volume of Distribution	0.9–1.1 L/kg (distribution primarily to bone, kidney, and liver; reflects extensive tissue binding).
Bioavailability	Subcutaneous: approximately 95% (bioequivalent to subcutaneous injection). Intranasal: not applicable. Intravenous: not approved.
Onset of Action	Subcutaneous: Stimulation of bone formation within 1 hour (increase in serum bone-specific alkaline phosphatase and P1NP); initial increase in serum calcium noted at 4–6 hours.
Duration of Action	Duration of biochemical effect: up to 12–24 hours (elevated bone formation markers). Clinical effect on BMD requires continuous daily dosing for at least 12–18 months. Maximum approved treatment duration: 24 months.

Classification & Brands

Action Class	Bone formation stimulator -PTH analogue
Brand Substitutes	Gemtide Injection, Gemtide Injection (2.4ml Each), Oflotas 200mg Tablet, Olox 200mg Tablet, Oflamed 200 Tablet, Oxa 200mg Tablet, Zenflox 200 Tablet, Horn O 200mg/500mg Tablet, Orni-O Tablet, Oflotas-OZ Tablet, Zorno Tablet, Ornof Tablet, OWINO Z 50 MG/125 MG SUSPENSION, Oflokem OZ Suspension, Bacter OZ Suspension, Maxxo OZ Suspension, Sinox OZ Suspension

Dosing & administration

20 mcg subcutaneously once daily.

Dosage form	SOLUTION
Renal impairment	No dose adjustment required for mild to moderate renal impairment (CrCl 30-89 mL/min). Not recommended for severe renal impairment (CrCl <30 mL/min) due to limited data.
Liver impairment	No dose adjustment required for mild to moderate hepatic impairment (Child-Pugh class A or B). Not studied in severe hepatic impairment (Child-Pugh class C).
Pediatric use	Not indicated for pediatric patients (safety and efficacy not established).
Geriatric use	No dose adjustment based on age alone; consider renal function and comorbidities.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for FORTEO (FORTEO).

Breastfeeding	Excretion into human milk unknown; however, teriparatide is a peptide hormone and likely degraded in infant GI tract. Low oral bioavailability suggests minimal systemic exposure. Caution advised. M/P ratio not determined.
Teratogenic Risk	FORTEO (teriparatide) is a Pregnancy Category C drug. In animal studies, teriparatide caused increased fetal skeletal abnormalities and soft tissue anomalies at doses 2-194 times the human exposure. No adequate human studies exist. Risk cannot be ruled out; use only if potential benefit justifies potential risk to fetus, especially during first trimester.

Warnings & precautions

■ FDA Black Box Warning

Increased risk of osteosarcoma in rats; avoid use in patients with Paget disease, unexplained alkaline phosphatase elevation, pediatric populations, or prior radiation therapy to the skeleton.