Beta blockers inhibit fetal thromboxane A2 production in vitro

Integrated metabolomics analysis reveals mechanistic insights into variability in blood pressure response to thiazide diuretics and beta blockers

Hypertensive patients with a higher proportion of genetic West African ancestry (%GWAA) have better blood pressure (BP) response to thiazide diuretics (TDs) and worse response to β-blockers (BBs) than those with lower %GWAA, associated with their lower plasma renin activity (PRA). TDs and BBs are suggested to reduce BP in the long term through vasodilation via incompletely understood mechanisms. This study aimed at identifying pathways underlying ancestral differences in PRA, which might reflect pathways underlying BP-lowering mechanisms of TDs and BBs. Among hypertensive participants enrolled in the Pharmacogenomics Evaluation of Antihypertensive Responses (PEAR) and PEAR-2 trials, we previously identified 8 metabolites associated with baseline PRA and 4 metabolic clusters (including 39 metabolites) that are different between those with GWAA <45% versus ≥45%. In the current study, using Ingenuity Pathway Analysis (IPA), we integrated these signals. Three overlapping metabolic signals within three significantly enriched pathways were identified as associated with both PRA and %GWAA: ceramide signaling, sphingosine 1- phosphate signaling, and endothelial nitric oxide synthase signaling. Literature indicates that the identified pathways are involved in the regulation of the Rho kinase cascade, production of the vasoactive agents nitric oxide, prostacyclin, thromboxane A2, and endothelin 1; the pathways proposed to underlie TD- and BB-induced vasodilatation. These findings may improve our understanding of the BP-lowering mechanisms of TDs and BBs. This might provide a possible step forward in personalizing antihypertensive therapy by identifying patients expected to have robust BP-lowering effects from these drugs.

Peripartum care of the cocaine-abusing parturient: are we ready?

Cocaine abuse in the United States is widespread, affecting more than 30 million people. Nearly 90% of cocaine-abusing women are of childbearing age. Cardiovascular complications of cocaine intoxication include dysrhythmias, ischemia and/or infarction, and account for most cocaine-related deaths. Pregnancy enhances the cardiovascular toxicity of cocaine. While the epidemiology, pathophysiology, clinical symptomatology and implications on pregnancy of cocaine addiction in pregnancy have received significant attention over the past 25 years, far too little attention has been given to the therapeutic considerations and peripartum care of the cocaine-abusing parturients. The timely treatment of acute cocaine-induced cardiovascular toxicity in pregnancy is by far the best predictor of good maternal and fetal outcome. However, no specific treatment guidelines are currently available for cocaine-induced cardiac dysrhythmias. This article discusses briefly several agents (and considers their mechanism of action) that have been proposed for the treatment of chest pain and other cardiovascular side-effects of cocaine toxicity in pregnancy.