Abaloparatide

Class and Category

Pharmacologic class: Parathyroid hormone analogue

Therapeutic class: Antiosteoporotic

Indications and Dosages

To treat postmenopausal women with osteoporosis who are at high risk for fracture, such as a history of multiple risk factors for fracture, have already sustained an osteoporotic fracture, or who have failed or are intolerant to other available osteoporosis therapy.

SUBCUTANEOUS INJECTION

Adult postmenopausal women. 80 mcg once daily.

Mechanism of Action

• Acts as an agonist at the PTH1 receptor, which activates the cAMP signaling pathway in target cells to increase bone mineral density and content. This in turn increases bone strength at vertebral and/or nonvertebral sites.

Contraindications

Hypersensitivity to abaloparatide or its components

Interactions

DRUGS

None

Adverse Reactions

CNS: Dizziness, fatigue, headache, vertigo

CV: Orthostatic hypotension, palpitations, tachycardia

GI: Abdominal pain (upper), nausea

GU: Hypercalciuria, urolithiasis

Other: Antiabaloparatide antibodies, elevated uric acid levels, hypercalcemia, injection site reactions (severe edema, pain, redness) 

Childbearing Considerations

PREGNANCY

• The drug is not indicated for use in females of reproductive potential.
• No human data on drug use in pregnant women is available.

LACTATION

• The drug is not indicated for use in females that would be breastfeeding.
• There is no information on drugs being present in breast milk, its effects on the breastfed infant, or the effects on milk production.

Nursing Considerations

• Know that abaloparatide and parathyroid hormone analogues such as teriparatide should not be given for more than 2 years cumulatively during the patient’s lifetime because of the potential risk of osteosarcoma.
• Be aware that abaloparatide should not be given to patients at increased risk for osteosarcoma. These risks include bone metastases or skeletal malignancies, hereditary disorders predisposing to osteosarcoma, open epiphyses, Paget’s disease of bone or unexplained elevations of alkaline phosphatase, or prior external beam or implant radiation therapy involving the skeleton.
• Know that abaloparatide should not be given to women with preexisting hypercalcemia or who have an underlying hypercalcemic disorder, such as primary hyperparathyroidism, because of the risk of exacerbating hypercalcemia.
• Administer abaloparatide only as a subcutaneous injection into the periumbilical region of the abdomen at about the same time every day. Never give intramuscularly or intravenously. Rotate injection site daily. Give first several doses where the patient can lie down or sit down, as orthostatic hypotension may occur.

• Monitor the patient for orthostatic hypotension for at least 4 hours after each dose.
• Monitor patient’s serum calcium levels, as ordered, because the drug may increase calcium levels, causing hypercalcemia, hypercalciuria, and urolithiasis. If preexisting hypercalciuria or urolithiasis is suspected, expect to measure the patient’s urinary calcium excretion, as ordered.
• Ensure that patient is receiving supplemental calcium and vitamin D if dietary intake is inadequate.

PATIENT TEACHING

• Inform patient that abaloparatide should not be given more than 2 years cumulatively in patient’s lifetime because of potential risk for osteosarcoma. Tell patient to immediately report persistent localized pain or occurrence of a new soft tissue mass that is tender to touch.
• Instruct the patient or caregiver how to administer a subcutaneous injection using the abaloparatide pen and how to properly dispose of the needle and pen.
• Emphasize the importance of not sharing the drug or needles with others. Also, tell the patient not to transfer the contents of the pen to a syringe.
• Tell the patient the pen must be discarded after 30 days of use, even if it still contains the unused solution.
• Advise patient to change positions slowly for at least 4 hours after abaloparatide has been given and to watch for a drop in her blood pressure with position changes. Symptoms to be alert for include dizziness, nausea, or a rapid heart rate. If present, tell the patient to lie down or sit until the symptoms pass.
• Instruct patient to report signs and symptoms of high calcium levels such as constipation, lethargy, muscle weakness, nausea, or vomiting. Inform the patient that she will need to have her calcium level checked routinely.
• Review dietary sources of calcium and vitamin D. Inform the patient that calcium and vitamin D supplementation will be needed if dietary intake is insufficient.