EDITOR, - John Kenny's editorial on overdose with calcium channel blocking drugs made several statements that could be misinterpreted with potentially serious results.1 Calcium channel blockers had similar effects in overdose despite differing therapeutic effects. A range of similar adverse effects have been reported in case reports, but death, and life threatening complications such as heart block and refractory hypotension, are much more common with verapamil than diltiazem.^2,3 Similarly, these effects are more common with diltiazem than nifedipine (and presumably other dihydropyridines).^2,3 This mirrors their relative effects on cardiac conduction in therapeutic …