Diltiazem adverse reactions

Diltiazem hydrochloride is a calcium ion influx inhibitor (slow channel blocker or calcium antagonist). It has generally been indicated for the treatment of angina and, more recently (2), hypertension. Diltiazem hydrochloride is a potent dilator of coronary arteries and has been shown to increase exercise tolerance in man. It is available for dosing as immediate release tablets and as extended or sustained release capsules and is usually well-tolerated. While some adverse reactions have been reported during diltiazem hydrochloride therapy, it is generally considered to be well-tolerated. In most cases, no causal relationship between the events and diltiazem hydrochloride use has yet to be established (1). 

The neurotoxic adverse reactions cited above for lithium and verapamil contrast with two other case reports describing uneventful concurrent use.i2 i3 Variable reports of altered serum-lithium levels have also occurred. This unpredictability emphasises the need to monitor the effects closely where it is thought appropriate to give lithium and verapamil. Only a couple of isolated reports of neurotoxicity have been reported with lithium and diltiazem, and their general relevance is uncertain, but bear them in mind in the event of an unexpected response to treatment. Some limited data suggest that nifedipine may slightly reduce lithium clearance, and the clinical relevance of this is again uncertain. 

Skin reactions ranging from exanthems to severe adverse events have been reported in association with diltiazem... 

SED-13, 513) (SEDA-18, 215) (SEDA-22, 216). Three cases of skin reactions (hypersensitivity syndrome reaction, pruritic exanthematous eruption, and acute generalized exanthematous pustulosis) possibly induced by diltiazem have been described and the literature on skin reactions associated with calcium antagonists has been reviewed. The number of diltiazem-induced cutaneous events was significantly greater than those induced by either nifedipine or verapamil. However, there was no difference in the proportion of serious cutaneous adverse events due to any of these three drugs (11). 

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