Discontinue use if extravasation occurs. Coronary, mesenteric or peripheral vascular thrombosis; patients w/ hypotension following MI; Prinzmetal's variant angina, diabetes, HTN or hyperthyroidism. Profound hypoxia or hypercabia. Frequently check BP & rate of flow to avoid HTN. Avoid abrupt w/drawal. Prolonged use. Concomitant use w/ MAOIs or TCAs. May affect ability to drive & use machines. Pregnancy & lactation. Not recommended in childn. Elderly.