From the Guidelines
Primary hyperparathyroidism (PHPT) can cause a range of side effects, including bone demineralization, fractures, nephrolithiasis, nephrocalcinosis, muscle weakness, and neurocognitive disorders, due to the excessive production of parathyroid hormone (PTH) and subsequent hypercalcemia. These side effects can be attributed to the disruption of normal calcium balance in the body, as excess PTH pulls calcium from bones into the bloodstream 1. Some common symptoms of PHPT include:
- Bone-related complications such as osteoporosis, bone fractures, and joint pain
- Kidney problems like nephrolithiasis, nephrocalcinosis, and decreased kidney function
- Muscle weakness and neurocognitive disorders like memory problems and difficulty concentrating
- Cardiovascular effects including high blood pressure, heart rhythm abnormalities, and increased risk of heart disease
- Gastrointestinal symptoms like abdominal pain, nausea, vomiting, and constipation
The severity of these side effects can vary widely among patients, with some experiencing minimal effects while others have significant complications 1. It is essential to note that the presentation of PHPT can differ depending on the country and routine biochemical screening practices, with asymptomatic cases being more common in countries where screening is routine 1. Treatment of PHPT typically involves surgical excision of the abnormally functioning parathyroid tissue, which can help alleviate these side effects and prevent long-term complications 1.
From the FDA Drug Label
In a randomized double-blind, placebo-controlled study of 67 patients with primary hyperparathyroidism for whom parathyroidectomy would be indicated on the basis of serum calcium levels, but who are unable to undergo surgery, the most common adverse reactions are listed in Table 4. Table 4 Adverse Reactions Occurring in ≥ 10% of Subjects in a Double-Blind, Placebo-Controlled Study in Patients with Primary Hyperparathyroidism Adverse Reaction Placebo (n = 34) n (%) Cinacalcet (n = 33) n (%) Nausea 6 (18) 10 (30) Muscle spasms 0 (0) 6 (18) Headache 2 (6) 4 (12) Back pain 2 (6) 4 (12)
The side effects of primary hyperparathyroidism (PHPT) are not directly stated in the label, but the common adverse reactions in patients with PHPT treated with cinacalcet are:
- Nausea
- Muscle spasms
- Headache
- Back pain 2
From the Research
Side Effects of Primary Hyperparathyroidism (PHPT)
- Renal complications:
- Hypercalciuria
- Nephrolithiasis
- Nephrocalcinosis 3
- Osteoporosis 3
- Hypercalcemia, which can be accompanied by various symptoms and complications 3
- Normocalcemic primary hyperparathyroidism, which may require calcium loading for diagnosis 3
Differential Diagnosis and Related Conditions
- Familial hypocalciuric hypercalcemia (FHH), a dominant autosomal disease that impairs parathyroid cell sensitivity to calcemia elevation 3
- Secondary hyperparathyroidism (SHP), which can be caused by various factors such as 25 OHvitD deficiency, kidney failure, renal hypercalciuria, malabsorption, and certain drugs 3
- Tertiary hyperparathyroidism (THP), which consists of autonomous PTH secretion by the parathyroid glands after prolonged stimulation under SHP 3
Consequences of Uncontrolled Hyperparathyroidism
- Soft-tissue and vascular calcification
- Cardiovascular disease
- Calcific uremic arteriolopathy (CUA)
- Neurological disturbances
- Hematological abnormalities
- Endocrine dysfunction 4