Allergy to class/drug
Closed angle glaucoma, Pheochromocytoma 
Caution if using postpartum with concomitant oxytocics
Caution in severe hypertension, history of cardiac disease
Caution with concomitant use of norepi-dopa reuptake inhibitors (e.g. bupropion, Ritalin)
Ephedrine
Pseudoephedrine
Naloxone
Remi-fentanil
Dexmedetomidine
Atropine
Thiopental
Homatropine