Here are my tips. I didn't take it online though but may help anyway...
*Keep up with you reading!
*Know the drug classifications, i.e. beta blockers, cephalosporins, loop diuretics, etc... Flash cards may be good for these.
*Know digoxin, it comes up a lot.
*Know the difference between cholinergic, anticholinergic, adrenergic, adrenergic antagonists, etc... and what effect they have on the body.
*Try to pick up on the major side effects or drug interactions, i.e. nitrates cause headaches or digoxin & lasix = hypokalemia.
*Also know the antidotes for overdoses, i.e. heparin= protamine sulfate, coumadin=vitamin K, etc...