Risk-benefits of antihypertensive drugs--beta-blockers.

Abstract

1. Beta-Blockers are of similar efficacy in the treatment of hypertension to other antihypertensive drugs of first choice; they have a wide spectrum of activity both alone and in combination. 2. Although beta-blockers first appear to worsen the haemodynamic changes of hypertension, subsequently peripheral resistance falls. The cardiovascular reflexes responsible for the responses of posture or other responses requiring normal functioning of alpha-mediated tone are not inhibited. 3. Important contra-indications are asthma and heart failure in susceptible subjects. Lipid soluble drugs have somewhat greater CNS side effects. 4. Triglyceride levels, notably an increase in VLDL and a fall in HDL occur from non-selective agents (less so from beta 1-selective agents) and there is a marginal effect from drugs with relatively high ISA. 5. In contrast to other antihypertensive drugs beta-blockers reduce the myocardial infarction rate in high risk patients (i.e. post-myocardial infarct). Results in primary prevention of mild hypertension have been less promising. 6. Those drugs which are lipid soluble and liver metabolized result in greater variation of plasma concentration after oral administration and some pharmacokinetic drug interactions. Once daily administration is possible with many beta-blockers. 7. beta-Blocking drugs have an established and proven place in the treatment of hypertension.