It isn’t the caffeine that’s the problem.
It’s the combination with EXCESSIVE ALCOHOL and PRESCRIBED MEDICATION, along with the caffeine that’s the dynamite.
All those items are in conflict with each other and cause the other items to react differently than they normally would. The prescription drugs are really a problem. When people don’t take medications correctly; this is the result.
It appears to me that “Mum” didn’t want to live. Sad.
Don’t believe she drank a liter of vodka every day. Nor do I believe that she drank 8 liters of Pepsi every day.