Images

Tranquilizers, whether antianxiety or antipsychotic agents, and antidepressants have effects on the cardiovascular system that are often overlooked by physicians. These effects can range from beneficial mildly antiarrhythmic actions to ECG changes that mimic those seen in MI, to heart block, ventricular fibrillation, and even death. Knowing which drugs are likely to produce which effects is the key to safe prescribing of these widely used and beneficial agents.

Tranquilizers, including both antianxiety and antipsychotic agents, and antidepressants are among the most frequently prescribed drugs in the United States today. Yet it is not widely enough appreciated that many of these agents have significant cardiovascular effects, some favorable and some adverse. This article will serve as a brief review of our knowledge concerning these psychotropic agents' effects on the cardiovascular system.

Images

A study was carried out to monitor directly the short-term effects of N2O/O2 inhalation-sedation on the peripheral microcirculation in healthy human subjects in a simulated dental setting. The inhalation of 40% N2O and 60% O2 led to a small but significant mean percent decrease (-6.89 ± 1.2 SEM) in relative vessel diameter in the nailfold capillaries, for the entire N2O-breathing period. Individual vessels showed a marked constriction (-31.7% ± 4.4 SEM, mean maximal decrease); the time to this maximum constriction varied with the individual vessels. This constriction could not be attributed to changes in oxygen or carbon dioxide levels in the alveolar gas, or to changes in heart rate, systolic blood pressure, respiratory rate or temperature. Further studies are indicated to determine whether this effect is sustained with long term administration, and whether it is clinically significant, especially in those patients with acquired cardiac disease or those taking vasoactive drugs.

Images