No interaction studies have been conducted except with digoxin, which slightly decreases imidapril levels, possibly because it reduces its absorption from the gut. Other potential interactions are not well studied: Rifampicin reduces the activation of imidapril to its active metabolite imidaprilat. Like other ACE inhibitors, imidapril increases potassium levels in the blood and can therefore cause hyperkalaemia, especially when combined with potassium-sparing diuretics or potassium substitution. Other diuretics, vasodilators, tricyclic antidepressants and antipsychotics can add to the antihypertensive effect of imidapril. Lithium can reach toxic levels when combined with imidapril. The effect of antidiabetic drugs can be increased, potentially causing hypoglycaemia (low blood glucose levels).