Shortness of breath, especially from minimal physical activity
Swelling in the hands and feet
Rapid and/or heavy heartbeat
Chest pain
Drug interactions
It is advised that those using isradipine not take dolasetron (Anzemet), as both agents can cause a dose-dependent PR interval and QRS complex prolongation.[4]
Itraconazole (Onmel/Sporanox) exhibits a negative inotropic effect on the heart and thus could spur an additive effect when used concomitantly with isradipine. Itraconazole also inhibits an important cytochromeliver enzyme (CYP 450 3A4) which is needed to metabolize isradipine and other calcium channel blockers. This will increase plasma levels of isradipine and could cause an unintentional overdose of the medication. Caution is advised when administering both agents together.[5]
Tizanidine demonstrates anti-hypertensive effects and should be avoided in patients taking isradipine due to the possibility of synergism between both medications.[6]
The antibioticrifampin lowered plasma concentrations of isradipine to below detectable limits.[2]
Cimetidine increased isradipine mean peak plasma levels. A downward dose adjustment may be necessary with this particular instance of polypharmacy.[2]
Severe hypotension was reported with fentanylanesthesia when it was combined with other calcium channel blockers. Even though isradipine, another calcium channel blocker, has not been used in conjunction with fentanyl anesthesia in any studies, caution is advised.[2]
Isradipine contains a stereocenter and consists of two enantiomers, more precisely atropisomers. This is a racemate, i.e. a 1: 1 mixture of (R)- and the (S)-forms:[7]
^Rote Liste Service GmbH (Hrsg.): Rote Liste 2017 – Arzneimittelverzeichnis für Deutschland (einschließlich EU-Zulassungen und bestimmter Medizinprodukte). Rote Liste Service GmbH, Frankfurt/Main, 2017, Aufl. 57, ISBN978-3-946057-10-9, S. 193.
Further reading
Hattori T, Wang P (2006). "Calcium antagonist isradipine-induced calcium influx through nonselective cation channels in human gingival fibroblasts". Eur J Med Res. 11 (3): 93–6. PMID16751108.
Fletcher H, Roberts G, Mullings A, Forrester T (1999). "An open trial comparing isradipine with hydralazine and methyl dopa in the treatment of patients with severe pre-eclampsia". J Obstet Gynaecol. 19 (3): 235–8. doi:10.1080/01443619964977. PMID15512286.