Teriparatide

INTRODUCTION

Indications

Treatment of osteoporosis in postmenopausal women at high risk for fractures. To increase bone mass in men with osteoporosis at high risk for fractures. Most useful for those have failed or are intolerant to other osteoporosis therapies.

Action

Regulates calcium and phosphate metabolism in bone and kidney by binding to specific cell receptors; stimulates osteoblastic activity. ↑ serum calcium and ↓ serum phosphorus. Therapeutic Effects: ↑ bone mineral density with reduced risk of fractures.

Adverse Reactions/Side Effects

CV: orthostatic hypotension. MS: muscle spasms.

PHYSICAL THERAPY IMPLICATIONS

Examination and Evaluation

• Assess blood pressure (BP) when patient assumes a more upright position (lying to standing, sitting to standing, lying to sitting). Document orthostatic hypotension and contact the physician when systolic BP falls >20 mm Hg, or diastolic BP falls >10 mm Hg.

• Assess any muscle spasms to rule out musculoskeletal pathology; that is, try to determine if pain is drug induced rather than caused by anatomic or biomechanical problems.

Interventions

• Institute weight-bearing and resistance exercises as tolerated to maintain or increase bone mineral density. Start with low impact or aquatic programs in patients with extensive demineralization, and increase exercise intensity slowly to prevent fractures.

• Protect against falls and fractures (See Appendix E). Modify home environment (remove throw rugs, improve lighting, etc.) and provide assistive devices (cane, walker) or other protective devices as needed to improve balance and prevent falls.

• To minimize orthostatic hypotension, patient should move slowly when assuming a more upright position.

Patient/Client-Related Instruction

• Advise patient about the benefits of proper diet in sustaining bone mineralization. If necessary, refer patient for nutritional counseling about supplemental calcium and vitamin D.

• Encourage patient to modify behaviors that increase the risk of osteoporosis (stop smoking, reduce alcohol consumption).

Pharmacokinetics

Absorption: Extensively absorbed after SC administration.

Distribution: Unknown.

Metabolism and Excretion: Metabolized by the liver; metabolites renally excreted.

Half-life: 1 hr (after SC use).

Contraindications/Precautions

Contraindicated in: Hypersensitivity; Paget's disease of the bone or other metabolic bone disease; Unexplained ↑ alkaline phosphatase; Pedi: Pediatric or young adult patients; Previous radiation therapy, history of bone metastases, or skeletal malignancy; Preexisting hypercalcemia; OB/Lactation: Pregnancy or lactation.

Use Cautiously in: Concurrent digoxin.

Interactions

Drug-Drug: Transient ...