A study in Sweden has shown that suicide rates are higher among patients taking calcium channel blockers prescribed for angina (chest pain) and high blood pressure.
In one part of the study, involving a survey of 152 Swedish municipalities with a total population of 7.3 million, the researchers found a five-fold increase in suicides among those taking calcium channel blockers compared with other treatments for high blood pressure.
In absolute terms this meant one extra suicide a year for every 1,000 people taking the drugs.
In the past, several groups of heart drugs have been linked to depression. Dr Anne Melander and colleagues of Malmo University Hospital, suggest in the British Medical Journal that one reason for the higher suicide rate in men observed in many Western countries could be that they have more heart disease and are therefore more likely to be prescribed heart drugs, and in particular calcium channel blockers.
Calcium channel blockers penetrate the blood brain barrier more easily than other heart drugs and "hence they have access to and may interfere with neurones and receptors involved in the regulation of mood," the researchers say. The drugs should be considered a possible cause of depression and suicide.
The study is the latest to ring alarm bells about calcium channel blockers, which have also been linked to a higher risk of heart attack in some patients. Those concerns were attributed to the early policy of giving high initial doses which were not tolerated well by patients with weak hearts. The new policy is to step up the dose more slowly over a longer period which appears to carry less risk.
Doubts remain however, and the current issue of the New England Journal of Medicine says that in the light of them, calcium channel blockers should be used as a second-line treatment only where other drugs, such as diuretics or beta-blockers, are unsuitable or have failed to work.Reuse content