Endocrine Abstracts

Introduction: Hypoparathyroidism is normally treated with calcium salts and activated vitamin D. Here we report a case where synthetic 1–34 PTH (teriparatide) and i.m. vitamin D was successful in treating a case of primary hypoparathyroidism resistant to conventional treatment.

Case report: A 16-year girl presented to the emergency department with vacant episodes and mild confusion. Her childhood was uneventful until the age of 12 when she developed recurrent seizures. She was known to have a prolonged QTc interval on her ECG and was under the care of the cardiologists. Her family history was unremarkable.

On admission, her corrected serum calcium was 1.59 mmol/l, phosphate 2.49 mmol/l and magnesium 0.78 mmol/l. The serum calcium had never been checked previously. Her PTH was 0.5 pmol/l, thyroid function tests, Vitamin B12 and a 0900 h cortisol level were within normal limits. Her 24 h urine calcium excretion was 1.5 mmol/24 h (2.5–7.5) and her 25-OH Vitamin D was 24 nmol/l (43–144). The rest of the routine blood tests were unremarkable.

Primary hypoparathyroidism was diagnosed and i.v. calcium was used to correct the serum calcium in the acute setting. Initial treatment with 1-α calcidiol and later calcitiriol along with oral calcium supplements were unsuccessful. Magnesium supplements were also given.

Due to the failure of conventional treatment and ongoing symptoms, i.m. vitamin D2 150 000 units once a week was added. There was no response and treatment with teriparatide 20 μg s.c. od was added. The patient initially stabilised but relapsed later and teriparatide was increased to 20 μg bd. Her serum calcium normalized with teriparatide and i.m. vitamin D2. Her symptoms of neuromuscular irritability subsided and the QTc interval improved.

Discussion: Medical literature on the use of 1–34 PTH in hypoparathyroidism is scarce. This case highlights the use of 1–34 PTH and i.m. vitamin D2 in the treatment of refractory hypoparathyroidism.