Monoamine oxidase inhibitors, particularly Nardil, can cause your blood pressure to drop when you stand up, which we call postural hypotension. If you stand or sit up quickly, you may become dizzy, feel uncoordinated, black out, or fall. This may occur when sitting up or rising from bed, standing up from a chair, or standing up after kneeling or bending down. Until you know whether you will have this side effect, it is important not to rise suddenly from sitting, lying, or bending-down positions. Always remember to sit or stand up slowly with your hand on a solid object for support so you will not fall if you become dizzy or black out. This side effect usually decreases with time.