[How does smoking affect blood pressure?].

It has been known for a long time that blood pressure and heart rate increase during smoking. These effects are associated specifically with nicotine. The rise in blood pressure is due both to an increase in cardiac output and in total peripheral vascular resistance. The rise in blood pressure occurs immediately, before any increase in circulating catecholamines. In hypertensives the blood pressure lowering effect of beta-blockers may be diminished by tobacco smoking whereas alpha-receptor blockers on the other hand seem to maintain their antihypertensive efficacy. It is a paradox that while smoking acutely increases blood pressure, some extensive epidemiological studies have shown a slightly lower blood pressure level among smokers than among non-smokers. Because blood pressure may rise after discontinuation of smoking, a smoking cessation programme should not postpone initiation of antihypertensive drug therapy in patients otherwise in need of such treatment.