Vitamins, supplements, and herbal hazards in heart disease
People are regularly taking vitamins and herbal remedies in higher quantities than ever before, often without mentioning these over-the-counter products to their doctors. Some agents have powerful effects on the cardiovascular system, while others can interact with heart medications to strengthen or weaken their effects.
A new meta-analysis suggests that vitamin-E supplementation would cause one additional hemorrhagic stroke for every 1250 individuals taking vitamin E and would prevent one ischemic stroke per 476 individuals taking vitamin E.
Doctors seeing patients in a cardiology clinic hardly ever asked patients about their use of nutraceuticals or over-the-counter medications, according to a new survey carried out by clinical pharmacists.
At present, there are few documented interactions with the new drugs, including dabigatran, rivaroxaban, and apixaban, but considering the extensive food and drug interactions with warfarin, caution should be taken with the new agents, according to researchers.
The safety of warfarin use can be compromised by many popular herbal and nonherbal supplements taken by individuals, with eight of the 10 mostly widely used supplements interacting with warfarin, and many of these associated with significant changes in the INR.
Omega-3 PUFAs from fish oil, started a day or two before surgery, didn't protect against the common post-CABG complication in a >200-patient placebo-controlled trial; on the other hand, researchers reported elsewhere at the HRS sessions that a much longer daily intake of fish-oil caps by patients with symptomatic SVT seemed to help stabilize the atria at electrophysiologic testing.
The largest study so far to examine the use of antioxidant doses of vitamins C and E to prevent the complications of pregnancy-associated hypertension, including preeclampsia, has found no benefit of this approach.
Results of a small randomized trial show that hibiscus tea given three times daily reduced systolic blood pressure by about 7 mm Hg in prehypertensive and mildly hypertensive subjects. (American Heart Association 2008 Scientific Sessions.)
Adding the widely used herbal medicinal to evidence-based drug therapy seemed to worsen HF progression almost immediately in a retrospective analysis of a randomized trial. (Zick SM et al. Eur J Heart Fail 2008; 10: 587-593.)
Measures of exercise performance appear to improve when hawthorn extract is given along with standard therapy, a new Cochrane review concludes. (Pittler MH et al. Cochrane Database Syst Rev; published online January 23, 2008.)
But it did show that the commercial preparation, derived from a medicinal plant used widely for centuries, was safe when added to conventional HF medications. The study also hinted that the drug may confer some protection against sudden death. (American College of Cardiology 2007 Scientific Sessions.)
Despite decades of research suggesting that garlic can improve cholesterol profiles, a new NIH-funded trial found absolutely no effects of raw garlic or garlic supplements on LDL, HDL, or triglycerides. The findings underscore the hazards of meta-analyses made up of small, flawed studies and the value of rigorously studying popular herbal remedies. (Gardner CD et al. Arch Intern Med 2007; 167:346-353.)
Noni, a traditional Polynesian remedy for a variety of health conditions, lowered total cholesterol and triglyceride levels in a group of healthy smokers after 30 days. (American Heart Association 46th Annual Conference on Cardiovascular Disease, Epidemiology, and Prevention.)
The two-day conference aimed to outline a research agenda on interactions between dietary supplements—used by an estimated 52% of Americans—and widely used agents such as warfarin and aspirin. (National Institutes of Health Conference on Dietary Supplements, Coagulation, and Antithrombotic Therapies.)
with slides / Pakistani researchers report that 1 g to 6 g of cinnamon daily reduced fasting serum glucose, triglyceride, LDL cholesterol, and total cholesterol levels over 40 days in type 2 diabetics. No such reductions were seen in placebo-treated diabetics. (Khan A et al. Diabetes Care 2003; 26:3215-8.)
Researchers have possibly found a pharmacologic basis for cases of arrhythmia among patients taking Metabolife 356, a top-selling herbal supplement containing ephedra. (American Heart Association Scientific Sessions 2003.)