At some point metoprolol (generic for Toprol XL
) became unavailable, was switched to brand name Toprol XL
, and have stayed with it since much fewer side effects, namely less "brain fog." My tachycardia seems to be set off by preservatives, incl sulfites/ates, nitrites/ates, flavor enhancers like monosodium glutamate, and red pepper flake. Black pepper in moderation doesn't seem to be a problem for me.