In Section 4.2 (Posology and method of administration) , Cholestagel should be administered at least four hours after the concomitant medication in order to minimize the risk of reduced absorption of the concomitant medication has been added, removing cholestagel should be administered one hour before.
In Section 4.4 (Special warnings and special precautions for use), Cholestagel can affect the bioavailability of the combined oral contraceptive pill when administered simultaneously. It is important to ensure that Cholestagel is administered at least 4 hours after the combined oral contraceptive pill to minimise the risk of any interaction has been added.
In Section 4.5 (Interaction with other medicinal products and other forms of interaction) the following paragraphs have been added;
Interaction studies have only been performed in adults.
There have been very rare reports of reduced phenytoin levels in patients who have received Cholestagel administered with phenytoin.
Levothyroxine
In an interaction study in healthy volunteers, Cholestagel reduced the AUC and Cmax of levothyroxine when administered either concomitantly or after 1 hour. No interaction was observed when Cholestagel was administered at least four hours after levothyroxine.
Combined oral contraceptive pill
In an interaction study in healthy volunteers, Cholestagel reduced the Cmax of norethindrone as well as the AUC and Cmax of ethinylestradiol when administered simultaneously with the combined oral contraceptive pill. This interaction was also observed when Cholestagel was administered one hour after the combined oral contraceptive pill. However no interaction was observed when Cholestagel was administered four hours after the combined oral contraceptive pill.
Antidiabetic agents
Co-administration of Cholestagel and glyburide (also known as glibenclamide) caused a decrease in the AUC0-inf and Cmax of glyburide by 32% and 47%, respectively. No interaction was observed when Cholestagel was administered four hours after glyburide.
Co-administration of Cholestagel and repaglinide had no effect on the AUC and caused a 19% reduction in the Cmax of repaglinide, the clinical significance of which is unknown. No interaction was observed when Cholestagel was administered one hour after repaglinide.
No interaction was observed when Cholestagel and pioglitazone were administered simultaneously in healthy volunteers
The Following paragraph has been removed.
The effect of thyroid replacement therapy should be monitored, since other bile acid sequestrants have been shown to reduce absorption of thyroxine. Specific clinical interaction studies with colesevelam and thyroid replacement therapy have not been performed. A reduced contraceptive effect cannot be excluded when colesevelam is administered to women taking oral contraceptives, as bile sequestrants have been shown to reduce the T1/2 of ethinylestradiol and the effect of colesevelam on ethinylestradiol pharmacokinetics has not been studied.
