Efficacy and safety of Renagel has not been studied in patients with:
• swallowing disorders
• active inflammatory bowel disease
• gastrointestinal motility disorders including untreated or severe gastroparesis, diverticulosis retention of gastric contents and abnormal or irregular bowel motion
• patients with a history of major gastrointestinal surgery
Therefore, caution should be exercised when Renagel is used in patients with these disorders.
Intestinal obstruction and ileus/sub-ileus
In very rare cases, intestinal obstruction and ileus/subileus have been observed in patients during treatment with sevelamer hydrochloride. Constipation may be a preceding symptom. Patients who are constipated should be monitored carefully while being treated with sevelamer hydrochloride. Renagel treatment should be re-evaluated in patients who develop severe constipation or other severe gastrointestinal symptoms.
Fat-soluble vitamins
Depending on diet intake and the nature of end stage renal failure, dialysis patients may develop low vitamin A, D, E and K levels. It cannot be excluded that Renagel can bind fat-soluble vitamins contained in ingested food. Therefore, in patients not taking these vitamins, monitoring vitamin A, D and E levels and assessing vitamin K status through the measurement of thromboplastin time should be considered and the vitamins should be supplemented if necessary. Additional monitoring of vitamins and folic acid is recommended in patients receiving peritoneal dialysis, since in the clinical study, vitamin A, D, E and K levels were not measured in these patients.
Folate deficiency
There is at present insufficient data to exclude the possibility of folate deficiency during long term Renagel treatment.
Hypocalcaemia/hypercalcaemia
Patients with renal insufficiency may develop hypocalcaemia or hypercalcaemia. Renagel does not contain calcium. Serum calcium levels should be monitored as is done in normal follow-up of a dialysis patient. Elemental calcium should be given as a supplement in case of hypocalcaemia.
Metabolic acidosis
Patients with chronic renal failure are predisposed to developing metabolic acidosis. Worsening of acidosis has been reported upon switching from other phosphate binders to sevelamer in a number of studies where lower bicarbonate levels in the sevelamer-treated patients compared to patients treated with calcium-based binders were observed. Closer monitoring of serum bicarbonate levels is therefore recommended.
Peritonitis
Patients receiving dialysis are subject to certain risks for infection specific to the dialysis modality. Peritonitis is a known complication in patients receiving peritoneal dialysis (PD) and in a clinical study with Renagel, a number of peritonitis cases were reported. Therefore, patients on PD should be closely monitored to ensure the reliable use of appropriate aseptic technique with the prompt recognition and management of any signs and symptoms associated with peritonitis.
Swallowing and choking difficulties
Uncommon reports of difficulty swallowing the Renagel tablet have been reported. Many of these cases involved patients with co-morbid conditions including swallowing disorders or oesophageal abnormalities. Caution should be exercised when Renagel is used in patients with difficulty swallowing.
Hypothyroidism
Closer monitoring of patients with hypothyroidism co-administered with sevelamer hydrochloride and levothyroxine is recommended (see section 4.5).
Long term chronic treatment
As data on the chronic use of sevelamer for over one year are not yet available, potential absorption and accumulation of sevelamer during long-term chronic treatment cannot be totally excluded (see section 5.2).
Hyperparathyroidism
Renagel alone is not indicated for the control of hyperparathyroidism. In patients with secondary hyperparathyroidism Renagel should be used within the context of a multiple therapeutic approach, which could include calcium supplements, 1,25-dihydroxy Vitamin D3 or one of its analogues to lower the intact parathyroid hormone (iPTH) levels.
Serum chloride
Serum chloride may increase during Renagel treatment as chloride may be exchanged for phosphorus in the intestinal lumen. Although no clinically significant serum chloride increase has been observed in the clinical studies, serum chloride should be monitored as is done in the routine follow-up of a dialysis patient. One gram of Renagel contains approximately 180 mg (5.1 mEq) chloride.
Inflammatory gastrointestinal disorders
Cases of serious inflammatory disorders of different parts of the gastrointestinal tract (including serious complications such as haemorrhage, perforation, ulceration, necrosis, colitis and colonic/caecal mass) associated with the presence of sevelamer crystals have been reported (see section 4.8). Inflammatory disorders may resolve upon sevelamer discontinuation. Sevelamer hydrochloride treatment should be re-evaluated in patients who develop severe gastrointestinal symptoms.