Teriparatide

Pronunciation: TER-i-PAR-a-tide
Class: Parathyroid hormone

Trade Names

Forteo
- Injection 250 mcg/mL

Pharmacology

Regulates bone metabolism, renal tubular reabsorption of calcium and phosphate, and intestinal calcium reabsorption.

Slideshow: Flashback: FDA Drug Approvals 2013

Pharmacokinetics

Absorption

Bioavailability is approximately 95% and T max is approximately 30 min.

Distribution

Vd is approximately 0.12 L/kg (IV dose).

Metabolism

Metabolized by nonspecific enzymatic mechanisms in the liver.

Elimination

Cl is approximately 62 L/h (women) and 94 L/h (men). Half-life is 5 min (IV) and 1 h (subcutaneous). Excreted via the kidneys.

Onset

2 h (serum calcium concentrations begin to increase).

Peak

4 to 6 h (peak serum calcium concentrations).

Duration

16 to 24 h (serum calcium concentrations return to baseline).

Special Populations

Renal Function Impairment

In patients with severe renal impairment (CrCl less than 30 mL/min), the AUC and half-life increased 73% and 77%, respectively. Maximum serum concentration was not increased.

Hepatic Function Impairment

No studies have been performed.

Elderly

No age-related differences in pharmacokinetics were detected.

Gender

Systemic exposure is approximately 20% to 30% lower in men; no dosage adjustment needed.

Indications and Usage

Treatment of postmenopausal women with osteoporosis who are at a high risk for fracture (eg, history of osteoporotic fracture); to increase bone mass in men with primary or hypogonadal osteoporosis who are at high risk of fracture (eg, history of osteoporotic fracture); treatment of men and women with osteoporosis associated with sustained systemic glucocorticoid therapy (daily dosage equivalent to prednisone 5 mg or more) at high risk of fracture (eg, history of osteoporotic fracture).

Contraindications

Hypersensitivity to teriparatide or to any of its excipients.

Dosage and Administration

Adults

Subcutaneous 20 mcg once daily into thigh or abdominal wall.

General Advice

  • Rotate injection sites (thigh, abdominal wall). Give new injections at least 1 inch from old site and never into areas where the skin is tender, bruised, red, or hard.
  • Administer initially under circumstances in which the patient can sit or lie down if symptoms of orthostatic hypotension occur.

Storage/Stability

Store at 36° to 46°F at all times. During the use period, minimize time out of the refrigerator; the dose can be administered immediately following removal from the refrigerator. Recap delivery device when not in use. Delivery device can be used for up to 28 days after first injection; discard after 28-day use period even if it still contains unused solution. Do not freeze. Discard if delivery device has been frozen.

Drug Interactions

Digoxin

Hypercalcemia may predispose patients to digitalis toxicity. Because teriparatide transiently increases serum calcium (4 to 6 h postdose), use teriparatide with caution in patients taking digoxin.

Loop diuretics (eg, furosemide)

In healthy patients and patients with mild, moderate, or severe renal insufficiency (CrCl 13 to 72 mL/min), coadministration of IV furosemide (20 to 100 mg) with teriparatide 40 mcg resulted in small increases in the serum calcium (2%) and 24-h urine calcium (37%) responses to teriparatide that did not appear to be clinically important.

Thiazide diuretics (eg, hydrochlorothiazide)

In healthy patients, coadministration of hydrochlorothiazide 25 mg with teriparatide did not affect the serum calcium response to teriparatide 40 mcg. The 24-h urine excretion of calcium was reduced by a clinically unimportant amount (15%). The effect of giving a higher dose of hydrochlorothiazide with teriparatide on serum calcium levels has not been studied.

Adverse Reactions

Cardiovascular

Hypertension (7%); angina pectoris, syncope (3%).

CNS

Asthenia (9%); dizziness, headache (8%); insomnia (5%); anxiety, depression, vertigo (4%).

Dermatologic

Rash (5%); sweating (2%); urticaria (postmarketing).

GI

Nausea (14%); gastritis (7%); constipation, diarrhea, dyspepsia (5%); vomiting (3%); GI disorder, tooth disorder (2%).

Metabolic

Hypercalcemia, hyperuricemia greater than 13 mg/dL (postmarketing).

Musculoskeletal

Arthralgia (10%); leg cramps (3%); muscle spasms of the leg or back (postmarketing).

Respiratory

Rhinitis (10%); dyspnea, increased cough, pharyngitis, pneumonia (6%); acute dyspnea, chest pain, orofacial edema.

Miscellaneous

Pain (21%); herpes zoster, neck pain (3%); anaphylaxis, angioedema, bone turnover and osteosarcoma, drug hypersensitivity, injection-site reactions including injection-site pain, swelling, and bruising (postmarketing).

Precautions

Warnings

Osteosarcoma

Increased incidence in rats. Dose and duration dependent. Should not be prescribed in patients who are at increased baseline risk for osteosarcoma (eg, open epiphyses, Paget disease, prior external beam or implant radiation therapy involving skeleton, unexplained elevations of alkaline phosphatase).


Monitor

Monitor serum calcium and phosphorous as needed. Consider measurement of urinary calcium excretion if active urolithiasis or preexisting hypercalciuria is suspected.


Pregnancy

Category C .

Lactation

Undetermined.

Children

Safety and efficacy not established.

Special Risk Patients

Do not administer to patients at increased risk of osteosarcoma (ie, children and young adults with open epiphyses, Paget disease, prior external beam or implant radiation therapy involving the skeleton, unexplained elevations of alkaline phosphate); do not use in patients with bone metastases or history of skeletal malignancies, metabolic bone diseases other than osteoporosis, or preexisting hypercalcemia or underlying hypercalcemia disorder (eg, primary hyperparathyroidism).

Long-term therapy

Use for more than 2 yr is not recommended.

Orthostatic hypotension

Symptomatic orthostatic hypotension may occur.

Urolithiasis

Use with caution.

Overdosage

Symptoms

Delayed hypercalcemic effect, dizziness, headache, nausea, orthostatic hypotension, vomiting, weakness/lethargy.

Patient Information

  • Instruct patient to read Medication Guide and pen user manual before starting therapy and each time the prescription is renewed.
  • Ensure that the patient understands how to store, prepare, and administer the dose and how to dispose of used equipment and supplies. The patients should perform the first injection under the supervision of a qualified health care provider.
  • Advise patient to inject prescribed dose at about the same time every day.
  • Advise patient that if a dose is missed to take it as soon as remembered, but to never administer more than 1 injection in the same day.
  • Advise patient to administer the first few doses in an area where they can sit or lie down quickly if they get dizzy.
  • Advise patient that if they feel light-headed or have palpitations after the injection to sit or lie down until symptoms resolve. Advise patient to notify health care provider if these symptoms persist or worsen.
  • Advise patient regarding other ways they can help their osteoporosis: supplemental calcium and vitamin D, weight-bearing exercises, and reduction of cigarette smoking and alcohol consumption.
  • Instruct patient to report the following symptoms to health care provider: persistent nausea, vomiting, constipation, tingling, lethargy, muscle weakness.
  • Inform patients of the increased incidence of osteosarcoma in rats and that the clinical relevance of these findings is unknown. Encourage patients to enroll in the voluntary teriparatide patient registry designed to collect information on the potential risk of osteosarcoma in humans.

Copyright © 2009 Wolters Kluwer Health.

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