Peptide education
Teriparatide
Forteo · PTH (1-34)
Teriparatide is a prescription medicine that helps build bone. It is made from the active first 34 amino acids of human parathyroid hormone. The U.S. product Forteo is used for specific forms of osteoporosis in people at high risk of fracture.
Teriparatide is a bone-building osteoporosis medicine with controlled fracture evidence in postmenopausal women. The U.S. Forteo label describes a daily injection, specific patient groups, and precautions that matter before and during treatment.
Overview
Quick answer
Forteo has different labeled indications for postmenopausal women, men with primary or hypogonadal osteoporosis, and people with osteoporosis associated with sustained systemic glucocorticoid treatment. The clinical evidence and endpoints are not identical across those groups.
Who is Forteo prescribed for?
Its U.S. label covers postmenopausal women at high fracture risk, men at high fracture risk with primary or hypogonadal osteoporosis, and men or women with osteoporosis associated with sustained systemic glucocorticoid use. The label also includes patients who failed or could not tolerate other available osteoporosis therapy.
What is the labeled dose?
Forteo's label specifies 20 mcg under the skin once daily, into the thigh or abdomen. The fracture prevention trial also studied 40 mcg daily, but that research dose is not the labeled Forteo dose.
Must treatment always stop at two years?
Not necessarily. The Forteo label says use beyond two years during a patient's lifetime should be considered only when the patient remains at or has returned to high fracture risk. The label also notes limited data about osteosarcoma risk beyond two years.
What did the fracture trial show?
Among postmenopausal women with prior vertebral fractures, new vertebral fractures occurred in 5% of the 444 evaluable women assigned 20 mcg daily and 14% of the 448 assigned placebo over a median 21 months of observation. Those group results do not predict a specific person's outcome.
Evidence
Evidence snapshot
Forteo is labeled for high-risk postmenopausal osteoporosis, increasing bone mass in certain men, and osteoporosis associated with sustained systemic glucocorticoid treatment.
In women with prior vertebral fractures, the 20 mcg group had a lower incidence of new vertebral fractures than placebo during the study.
A randomized study in men and women taking systemic glucocorticoids reported greater spine bone-density gain and fewer new vertebral fractures with teriparatide than alendronate.
Label precautions include dizziness on standing, high calcium, urinary stones, hypersensitivity, calciphylaxis, and risk factors for osteosarcoma.
Claims
Common claims vs evidence
| Claim | Human evidence | Mechanistic evidence | Verdict |
|---|---|---|---|
| Teriparatide reduces fractures in postmenopausal osteoporosis. | The fracture prevention trial randomized women with prior vertebral fractures to placebo or daily PTH (1-34). New vertebral fractures occurred in 5% of 444 evaluable women in the 20 mcg group versus 14% of 448 in the placebo group over a median 21 months of observation. Nonvertebral fragility fractures were also less frequent in the teriparatide groups. | Intermittent PTH1 receptor signaling stimulates bone formation, and clinical studies measured increases in bone mineral density. | Supported in the studied postmenopausal population. These results do not mean that treatment eliminates fracture risk for an individual. |
| Teriparatide has evidence in glucocorticoid-associated osteoporosis. | An 18-month trial randomized 428 men and women with osteoporosis and sustained glucocorticoid exposure to teriparatide or alendronate. The teriparatide group had greater lumbar spine bone-density gains and fewer new vertebral fractures. | Supported within the studied osteoporosis and glucocorticoid context. The comparison was with alendronate, not placebo. Vertebral fractures were few, and the study was powered for bone density, not fracture outcomes. | |
| Treatment beyond two years is always forbidden. | The current U.S. Forteo label allows consideration beyond two years of lifetime use only for a patient who remains at or has returned to high fracture risk. It notes limited data on osteosarcoma risk beyond that period. | A longer course is an exception requiring clinical assessment, not an automatic extension or an absolute prohibition. | |
| The ACTIVE study proves one bone-building drug is better at preventing vertebral fractures. | ACTIVE compared blinded abaloparatide with placebo and included open-label teriparatide. Its primary vertebral-fracture comparison was abaloparatide versus placebo, not a powered comparison between the active drugs. | The study provides important context, but separate placebo results do not establish which active treatment is superior for vertebral fracture. |
Bottom line
Main takeaway
Forteo is a prescription medicine for certain people whose bones are vulnerable to fracture. It is not a general supplement. The decision to use it depends on medical history and the cause and severity of osteoporosis.
Ask which fracture outcomes were measured, in which patients, and against which comparator. A study in women with previous vertebral fractures does not answer every question about osteoporosis in men or steroid users.
Read the Forteo label with the fracture prevention and glucocorticoid trials. Note the dose arms, observation periods, comparator, and endpoints.
Identity
What it is
Teriparatide corresponds to the first 34 amino acids of human parathyroid hormone. Forteo is supplied as a single-patient-use pen containing a defined solution for subcutaneous injection.
The U.S. label includes osteoporosis associated with sustained systemic glucocorticoid therapy at a daily dose equivalent to at least 5 mg of prednisone, subject to its high-risk or prior-treatment criteria.
Use context
Routes, doses, and cycle patterns
Forteo is injected once daily. The prescribed course depends on fracture risk and medical history; the fracture prevention trial also studied a higher dose than the labeled Forteo dose.
Human studies and product labels
Forteo U.S. label
- Purpose
- Treatment of labeled high-risk osteoporosis populations
- Context
- Approved prescription product
- Route
- Subcutaneous injection in the thigh or abdomen
- Amount
- 20 mcg
- Frequency
- Once daily
- Duration
- More than two years only considered for continuing or renewed high fracture risk
The label advises giving initial doses where the patient can sit or lie down if lightheaded. Calcium and vitamin D supplementation is addressed when dietary intake is inadequate.
Fracture prevention trial
- Purpose
- Fracture outcomes in postmenopausal women with prior vertebral fractures
- Context
- Study-reported regimen, not a recommendation
- Route
- Subcutaneous
- Amount
- 20 mcg or 40 mcg in separate trial arms
- Frequency
- Once daily
- Duration
- Median treatment exposure of 19 months
Both doses were compared with placebo. The 40 mcg arm was a research dose and is not the labeled Forteo regimen. Median observation was 21 months.
Glucocorticoid-associated osteoporosis trial
- Purpose
- Bone density and fracture outcomes during sustained steroid exposure
- Context
- Study-reported regimen, not a recommendation
- Route
- Subcutaneous
- Amount
- 20 mcg
- Frequency
- Once daily
- Duration
- 18 months
The active comparator was oral alendronate, not placebo.
What varies
- The Forteo pen is refrigerated at 2 to 8 C except during administration. It should not be frozen and is discarded 28 days after first use, even if solution remains. Other teriparatide products can have their own instructions.
- Tell the prescriber about high blood calcium, kidney stones, prior skeletal radiation or bone cancer, and medicines such as digoxin. The label describes specific precautions for these situations.
- If pregnancy occurs or breastfeeding is being considered, discuss the medicine promptly with the prescribing clinician; the label addresses these situations separately.
Research
Research evidence
The fracture prevention study directly assessed new fractures in women with prior vertebral fractures. The glucocorticoid study compared teriparatide with an active osteoporosis medicine, and the Forteo label also summarizes a bone density study in men.
| Study / evidence area | Population | Design | Product context | Main outcome | Limitations | Weight |
|---|---|---|---|---|---|---|
| Fracture prevention trial | 1,637 postmenopausal women with prior vertebral fractures | Randomized, placebo-controlled, two teriparatide dose groups | Daily subcutaneous 20 mcg or 40 mcg, with the latter not the labeled Forteo dose | New vertebral fractures in 5% of 444 evaluable women with 20 mcg versus 14% of 448 with placebo | Not all randomized women had evaluable radiographs. Median treatment exposure was 19 months and median observation was 21 months; participants had prior vertebral fractures. | Controlled fracture endpoint in a defined population |
| Glucocorticoid-associated osteoporosis trial | 428 men and women with osteoporosis receiving sustained glucocorticoids | Randomized, double-blind, active-controlled | Daily subcutaneous 20 mcg teriparatide or daily oral alendronate for 18 months | Greater spine bone-density gains and fewer new vertebral fractures with teriparatide | Manufacturer-funded study powered for bone density, with few vertebral fractures and an active comparator | Controlled evidence in glucocorticoid-associated osteoporosis |
| Male osteoporosis study summarized in the label | Men with primary or hypogonadal osteoporosis | Randomized, placebo-controlled | Forteo 20 mcg subcutaneously once daily | Greater lumbar spine bone-density gain than placebo | Bone-density results are not direct fracture-reduction proof in this trial | Controlled bone-density endpoint in men |
Cautions
Safety and unknowns
- Pain, nausea, and joint aches are common adverse reactions in the label. Some people experience dizziness or a blood-pressure drop on standing, particularly around the first doses.
- Teriparatide can raise blood calcium. People with an underlying high-calcium disorder such as primary hyperparathyroidism should avoid Forteo according to the label. Urinary calcium and active or recent kidney stones may also need assessment.
- Osteosarcoma occurred in rat studies. The label states that an increased risk has not been observed in human observational studies, while data beyond two years remain limited. It advises avoiding Forteo in people with certain elevated baseline risks, such as skeletal radiation, bone malignancy, Paget's disease, or open growth plates.
- The label warns about serious allergic reactions, calciphylaxis, and possible digoxin toxicity. Swelling of the face or throat or trouble breathing can signal a serious allergic reaction and requires urgent medical attention.
Product quality
Product identity and quality
Forteo is a specific prescription product with a defined pen, concentration, and cold-storage instructions. Its label does not verify the identity or sterility of a non-prescription product using the teriparatide name.
Product identity
A name on an unapproved vial does not establish equivalence to a prescription pen.
Refrigeration and disposal
Forteo has product-specific storage and a 28-day in-use period.
Medication history
Prior treatment, calcium disorders, and other medicines affect clinical decisions.
Mechanism
How it is proposed to work
Teriparatide gives a brief parathyroid hormone signal that stimulates bone formation when given once daily. It can increase bone mineral density in the populations studied.
Teriparatide binds the PTH1 receptor. The effect of parathyroid hormone signaling on bone depends in part on the pattern of exposure.
Bone-density changes and fracture outcomes are related but distinct measurements. A study measuring one does not automatically prove the other.
FAQ
Common questions
Is treatment always stopped after two years?
The Forteo label says use beyond two years during a patient's lifetime should be considered only if the patient remains at or has returned to high fracture risk.
Is the studied 40 mcg dose the Forteo label dose?
No. The fracture prevention trial included 20 mcg and 40 mcg research groups; the current Forteo label specifies 20 mcg once daily.
Details
Technical details
Sources
References
- 1.
DailyMed. Forteo prescribing information
U.S. product label for indications, administration, duration, storage, and safety.
- 2.
doi:10.1056/NEJM200105103441904 PMID:11346808
Randomized fracture trial comparing daily 20 mcg or 40 mcg parathyroid hormone (1-34) with placebo.
- 3.
PubMed. Teriparatide or alendronate in glucocorticoid-induced osteoporosis
doi:10.1056/NEJMoa071408 PMID:18003959
Randomized comparison in men and women with osteoporosis associated with sustained glucocorticoid use.
- 4.
doi:10.1001/jama.2016.11136 PMID:27533157 NCT01343004
Randomized placebo comparison with an open-label teriparatide arm in postmenopausal women.