| The number of adverse effects reported from clinical use of Rocaltrol over a period of 15 years in all indications is very low with each individual effect, including hypercalcaemia, occurring rarely ( 0.001%).Since calcitriol exerts vitamin D activity, adverse effects may occur which are similar to those found when an excessive dose of vitamin D is taken, i.e. hypercalcemia syndrome or calcium intoxication (depending on the severity and duration of hypercalcemia). (See section 4.2 Posology and method of administration, and section 4.4 Special warnings and precautions for use).Hypercalcaemia and hypercalcuria are the major side effects of Rocaltrol and indicate excessive dosage. Patients with tertiary hyperparathyroidism, renal failure, or on regular haemodialysis are particularly prone to develop hypercalcaemia. The clinical features of hypercalcaemia include anorexia, constipation, nausea, vomiting, headache, weakness, apathy and somnolence. More severe manifestations may include fever, thirst/polydipsia, dehydration, polyuria, nocturia, abdominal pain, paralytic ileus, cardiac arrhythmias and psychiatric disturbances. Rarely, overt psychosis and metastatic calcification (particularly nephrocalcinosis and renal stones) may occur. The relatively short biological half-life of Rocaltrol permits rapid elimination of the compound when treatment is stopped and hypercalcaemia will recede within 2 - 7 days. This rate of reversal of biological effects is more rapid than when other vitamin D derivatives are used.In patients with normal renal function, chronic hypercalcaemia may be associated with an increase in serum creatinine.Because of the short biological half-life of calcitriol, pharmacokinetic investigations have shown normalization of elevated serum calcium within a few days of treatment withdrawal, i.e. much faster than in treatment with vitamin D3 preparations.Mild, non-progressive and reversible elevations in levels of liver enzymes (SGOT, SGPT) have been noted in a few patients treated with Rocaltrol, but no pathological changes in the liver have been reported.In concurrent hypercalcemia and hyperphosphatemia of> 6 mg/100 ml or> 1.9 mmol/l, soft-tissue calcification may occur; this can be seen radiographically. Hypersensitivity reactions (pruritus, rash, urticaria and, very rarely, severe erythematous skin disorders) may occur in susceptible individuals. | |