Popular High Blood Pressure Drug Linked To Sudden Cardiac Arrest Risk

A common calcium-channel blocking heart medication has been tentatively linked to increased risk of sudden cardiac arrest. The research comes from the European Sudden Cardiac Arrest network (ESCAPE-NET), though additional work is needed to determine whether the findings can be replicated. At the heart of the study were medications amlodipine and nifedipine, which are prescribed for high blood pressure and chest pain called angina.

As part of the study, researchers looked into whether the two aforementioned medications are linked to cardiac arrest cases that happened outside of a hospital setting. Data on these cases was pulled from the Dutch Amsterdam Resuscitation Studies registry and the Danish Cardiac Arrest Registry.

The study looked at the most commonly prescribed doses of each medication: 30mg and 60mg (and, rarely, 90mg) of nifedipine and 5mg and 10mg for amlodipine. An analysis involving data from both registries was performed, the first involving 2,503 patients and the latter involving 8,101 patients. Controls numbered 10,543 and 40,505, respectively.

When it came to nifedipine, the study found a link between doses greater than 60mg a day and cardiac arrest cases that happened outside of a hospital — the high-dose cases were 'significantly associated' with these cardiac arrests. The increased risk was compared to use of amlodipine and non-use of dihydropyridines.

In contrast, the study didn't find a risk associated with taking the medication amlodipine. ESCAPE-NET project leader Dr. Hanno Tan explained:

This study suggests that high-dose nifedipine may increase the risk of sudden cardiac arrest due to fatal cardiac arrhythmia while amlodipine does not. If these findings are confirmed in other studies, they may have to be taken into account when the use of either drug is considered.