Drug Guide
Teriparatide
Classification
Therapeutic: Bone mineral regulatory agent
Pharmacological: Recombinant parathyroid hormone analog
FDA Approved Indications
- Treatment of osteoporosis in postmenopausal women and men at high risk for fracture
Mechanism of Action
Stimulates osteoblastic activity, promoting new bone formation by intermittently activating parathyroid hormone receptors, thereby increasing bone mass.
Dosage and Administration
Adult: 20 micrograms subcutaneously once daily
Pediatric: Not indicated for pediatric use
Geriatric: Use with caution; adjust based on renal function and risk factors
Renal Impairment: Use caution; contraindicated in patients with hypercalcemia or severe renal impairment
Hepatic Impairment: No specific dose adjustment necessary
Pharmacokinetics
Absorption: Rapidly absorbed after subcutaneous injection
Distribution: Wide distribution including bone tissue
Metabolism: Metabolized by proteolytic enzymes; not CYP450 dependent
Excretion: Renal; primarily as metabolites
Half Life: 1 hour (terminal half-life)
Contraindications
- History of osteosarcoma
- Paget’s disease of bone
- Elevated serum calcium levels
Precautions
- Assess serum calcium before and during therapy, avoid in hypercalcemia, monitor for orthostatic hypotension, and caution in patients with increased risk for osteosarcoma
Adverse Reactions - Common
- Nausea (Likely)
- Leg cramps (Likely)
- Orthostatic hypotension (Likely)
Adverse Reactions - Serious
- Osteosarcoma (animal studies) (Rare but serious; human risk unknown)
- Hypercalcemia (Uncommon; monitor serum calcium)
Drug-Drug Interactions
- Thyroid hormones (may increase hypercalcemia risk)
- Digoxin (monitor for toxicity)
Drug-Food Interactions
- Calcium and vitamin D supplements (may interfere with absorption)
Drug-Herb Interactions
N/ANursing Implications
Assessment: Monitor serum calcium, phosphate, and alkaline phosphatase levels; assess for signs of hypercalcemia
Diagnoses:
- Risk for impaired bone integrity
- Risk for hypercalcemia
Implementation: Administer subcutaneous injection daily as prescribed, educate patient on injection technique, monitor for adverse effects
Evaluation: Assess bone density improvements, monitor for adverse effects, evaluate calcium levels regularly
Patient/Family Teaching
- Instruct on correct injection technique
- Avoid concurrent use of other bone-modulating agents without healthcare provider advice
- Report symptoms of hypercalcemia (confusion, muscle weakness, nausea)
- Recommend adequate calcium and vitamin D intake
Special Considerations
Black Box Warnings:
- Potential risk of osteosarcoma, primarily based on animal studies; use only in indicated populations
Genetic Factors: None identified
Lab Test Interference: None known
Overdose Management
Signs/Symptoms: Severe hypercalcemia, nausea, vomiting, weakness, confusion
Treatment: Discontinue drug, provide hydration, manage hypercalcemia with calcium-binding agents if needed
Storage and Handling
Storage: Store in a refrigerator at 2-8°C (36-46°F); protect from light
Stability: Stable until expiration date when refrigerated