Hypoparathyroidism is treated with oral calcium carbonate and vitamin D analogues to increase serum calcium levels. Recombinant human parathyroid hormone (rhPTH) therapy can be considered in patients with poorly controlled hypocalcaemia or side effects to conventional treatment. Constipation, a known side effect of calcium carbonate, is often easily managed with simple laxatives. We describe resolution of severe constipation by changing conventional treatment to rhPTH. A female patient, diagnosed with 22q11 deletion and hypocalcaemia during the neonatal period, was managed with calcium supplements. She developed constipation at 4-years-old when she was commenced on Movicol. Strategies such as star charts and reward systems were also trialled. Unfortunately, the patient developed soiling and management was escalated to Picolax and then Botox and manual extraction. The patient was referred to endocrinology at 6-years-old and was commenced on Alfacalcidol, which improved her bowels for a short period. Calcium supplements were weaned at the age of 6.5 years, as the patient found them difficult to take with her constipation. Overtime, Alfacalcidol was increased to 85nanogram/kg/day and her vitamin D levels were optimised. At 9-years-old, the patient experienced seizure-like activity and was found to have an adjusted calcium level of 1.82mmol/l (2.15-2.74), phosphate level of 2.21mmol/l (0.97-1.94) and inappropriately low PTH of 2.2pmol/l (1.1-6.9). She was re-commenced on oral calcium, but control remained poor (adjusted calcium ranged from 1.58 to 2.02mmol/l and phosphate ranged from 1.85 to 2.58mmol/L) and she was requiring regular surgical intervention for constipation. She was admitted at 12 years of age for rhPTH (Terrosa) therapy subcutaneously. The dose was initiated at 0.31micrograms/kg/dose twice daily and increased in stages to 0.40micrograms/kg/dose twice daily. Table 1 shows improvement of bone biochemistry following rhPTH. Her bowel movements have improved. She has remained on oral laxatives but has not required surgical intervention to date since starting rhPTH. Recombinant human PTH therapy can be used successfully to wean calcium supplements and reduce severe complications secondary to the oral medication. It also improves compliance and overall bone biochemistry.
|Level||Pre-rhPTH||3 days post-rhPTH||2 weeks post-rhPTH||4 weeks post-rhPTH|
|Calcium mmol/l (2.15-2.74)||1.59||1.92||2.27||2.43|
|Adjusted calcium mmol/l (2.15-2.74)||1.67||1.94||2.17||2.31|
|Phosphate mmol/l (0.81-1.61)||2.76||2.39||1.54||1.63|
|Parathyroid hormone pmol/l (1.1-6.9)||1.9||NA||NA||NA|
|Urine calcium/creatinine ratio mm/mmCr (0-0.6)||0.07||NA||0.49||NA|
15 Sep 2022 - 17 Sep 2022