teriparatide

teriparatide,

a parathyroid hormone used to treat postmenopausal women with osteoporosis and men with primary hypogonadal osteoporosis at high risk for fracture.

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teriparatide (recombinant)

Forsteo (UK), Forteo

Pharmacologic class: Biosynthetic fragment of human parathyroid hormone

Therapeutic class: Parathyroid hormone

Pregnancy risk category C

FDA Boxed Warning

• In male and female rats, drug increased incidence of osteosarcoma (malignant bone tumor). Because of uncertain relevance of this finding to humans, use drug only in patients for whom potential benefits outweigh potential risk. Don't administer to patient at increased baseline risk for osteosarcoma.

Action

Stimulates new bone growth by binding to specific high-affinity cell-surface receptors

Availability

Injection: 750 mcg/3 ml (controlled pen device)

⊘Indications and dosages

➣ Osteoporosis in patients at high risk for bone fracture

Adults: 20 mcg/day subcutaneously for up to 2 years

Contraindications

• Hypersensitivity to drug
• Conditions that increase osteosarcoma risk (such as Paget's disease, unexplained alkaline phosphatase elevation, open epiphyses, skeletal radiation therapy)
• Bone cancer metastases or history of bone cancer
• Metabolic bone disease other than osteoporosis
• Hypercalcemia

Precautions

Use cautiously in:
• urolithiasis, hypotension
• concurrent use of cardiac glycosides
• pregnant or breastfeeding patients.

Administration

• Inject subcutaneously into thigh or abdominal wall, with patient lying down.
• Know that prefilled injection pen delivers 20 mcg of drug per actuation and may be reused for up to 28 days after first injection. Discard pen in protected container after 28 days, even if it's not empty.

Route	Onset	Peak	Duration
Subcut.	Rapid	Rapid	Unknown

Adverse reactions

CNS: dizziness, headache, insomnia, depression, vertigo, asthenia

CV: hypertension, angina, syncope

EENT: rhinitis, pharyngitis

GI: nausea, vomiting, diarrhea, dyspepsia, anorexia

Metabolic: hyperuricemia

Musculoskeletal: joint pain, cramps

Respiratory: cough, dyspnea, pneumonia

Skin: rash, sweating

Other: pain

Interactions

Drug-drug. Digoxin: increased digoxin toxicity

Drug-diagnostic tests. Calcium: increased level

Patient monitoring

• Monitor respiratory and neurologic status and assess patient's mood.
• Monitor bone mineral density tests and calcium level.

Patient teaching

• Instruct patient to promptly report such adverse reactions as cough and difficulty breathing.
• Tell patient that prefilled injection pen delivers 20 mcg of drug per actuation. Inform him that he may reuse it for up to 28 days after first injection, and should then discard it in appropriate receptacle, even if it's not empty.
• Advise patient to establish effective bedtime routine to minimize insomnia.
• Caution patient to avoid driving and other hazardous activities until he knows how drug affects strength and balance.
• As appropriate, review all other significant adverse reactions and interactions, especially those related to the drugs and tests mentioned above.