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Natpara Side Effects

Generic name: parathyroid hormone

Medically reviewed by Drugs.com. Last updated on May 12, 2020.

Note: This document contains side effect information about parathyroid hormone. Some of the dosage forms listed on this page may not apply to the brand name Natpara.

In Summary

Common side effects of Natpara include: decreased serum calcium, diarrhea, hypercalcemia, increased serum calcium, increased urine calcium excretion, vomiting, and hypocalcemia. See below for a comprehensive list of adverse effects.

For the Consumer

Applies to parathyroid hormone: subcutaneous powder for solution

Warning

Subcutaneous route (Powder for Solution)

In male and female rats, parathyroid hormone caused an increase in the incidence of osteosarcoma (a malignant bone tumor). The occurrence of osteosarcoma was dependent on parathyroid hormone dose and treatment duration. This effect was observed at parathyroid hormone exposure levels ranging from 3 to 71 times the exposure levels in humans receiving a 100 mcg dose of parathyroid hormone. These data could not exclude a risk to humans.Because of a potential risk of osteosarcoma, use parathyroid hormone only in patients who cannot be well-controlled on calcium and active forms of vitamin D alone and for whom the potential benefits are considered to outweigh this potential risk.Avoid use of parathyroid hormone in patients who are at increased baseline risk for osteosarcoma, such as patients with Paget’s disease of bone or unexplained elevations of alkaline phosphatase, pediatric and young adult patients with open epiphyses, patients with hereditary disorders predisposing to osteosarcoma or patients with a prior history of external beam or implant radiation therapy involving the skeleton.Because of the risk of osteosarcoma, parathyroid hormone is available only through a restricted program under a Risk Evaluation and Mitigation Strategy (REMS) called the NATPARA REMS Program.

Side effects requiring immediate medical attention

Along with its needed effects, parathyroid hormone (the active ingredient contained in Natpara) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking parathyroid hormone:

More common

  • Abdominal or stomach cramps or pain
  • blurred vision
  • confusion
  • constipation
  • convulsions
  • depression
  • difficulty with breathing
  • dizziness
  • dry mouth
  • headache
  • incoherent speech
  • increased urination
  • irregular heartbeats
  • loss of appetite
  • metallic taste
  • muscle cramps in the hands, arms, feet, legs, or face
  • muscle weakness
  • nausea
  • nervousness
  • numbness and tingling around the mouth, fingertips, or feet
  • pounding in the ears
  • slow or fast heartbeat
  • thirst
  • tremor
  • unusual tiredness
  • vomiting
  • weight loss

Side effects not requiring immediate medical attention

Some side effects of parathyroid hormone may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

  • Abnormal or decreased touch sensation
  • body aches or pain
  • chills
  • cough
  • diarrhea
  • difficulty with moving
  • ear congestion
  • fever
  • loss of voice
  • muscle pain or stiffness
  • pain in the joints or neck
  • pain or tenderness around the eyes and cheekbones
  • sneezing
  • sore throat
  • stuffy or runny nose
  • tightness of the chest
  • upper abdominal or stomach pain

For Healthcare Professionals

Applies to parathyroid hormone: subcutaneous powder for injection

General

The more commonly reported adverse reactions have included paresthesia, hypocalcemia, headache, hypercalcemia, nausea, hypoesthesia, diarrhea, vomiting, arthralgia, hypercalciuria, and extremity pain.

Metabolic

Hypocalcemia combines reported events of hypocalcemia and blood calcium decreased; hypercalciuria combines reported events of hypercalciuria and urine calcium increased; and hypercalcemia combines reported events of hypercalcemia and blood calcium increased.

During clinical trials, 3 patients receiving this drug required IV fluids to correct hypercalcemia. In the postmarketing period, seizures due to hypocalcemia have been reported. The risk of hypocalcemia increases when this drug is withdrawn.[Ref]

Very common (10% or more): Hypocalcemia (27%), hypercalcemia (19%); hypercalciuria (11%)[Ref]

Nervous system

Very common (10% or more): Paresthesia (31%), headache (25%), hypoesthesia (14%)

Common (1% to 10%): Facial hypoesthesia

Postmarketing reports: Seizures due to hypocalcemia[Ref]

Hypersensitivity

Postmarketing reports: Hypersensitivity reactions including anaphylaxis, dyspnea, angioedema, urticaria, rash

Cardiovascular

Common (1% to 10%): Hypertension[Ref]

Gastrointestinal

Very common (10% or more): Nausea (18%), diarrhea (12%), vomiting (12%)

Common (1% to 10%): Upper abdominal pain[Ref]

Musculoskeletal

Very common (10% or more): Arthralgia (11%), pain in extremity (10%)

Common (1% to 10%): Neck pain[Ref]

Immunologic

Common (1% to 10%): Immunogenicity[Ref]

Genitourinary

Common (1% to 10%): Blood 25-hydroxycholecalciferol decreased[Ref]

Respiratory

Common (1% to 10%): Upper respiratory tract infection, sinusitis[Ref]

References

1. "Product Information. Natpara (parathyroid hormone)." NPS Pharmaceuticals, Bedminster, NJ.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.