Drug adulteration of sexual enhancement supplements: a worldwide insidious public health threat.

Worldwide, the consumption of dietary supplements for the enhancement of sexual performance is common. Consumers are generally fond of these products because they often want to avoid drugs, preferring "natural" than "chemical" solutions. This is challenging, as many of these supplements labelled "herbal" or "natural" are actually adulterated with drugs, mainly phosphodiesterase-5 inhibitors. This phenomenon is facilitated by fewer demanding regulations for marketing supplements. Thus, consumers may be widely exposed to serious adverse events, such as acute liver injury, kidney failure, pulmonary embolism, stroke or even death. We aim to warn physicians about this issue. This multidisciplinary review simultaneously deals with clinical consequences of this phenomenon, analytical toxicology and regulation. Indeed, after outlining this worldwide issue and highlighting that a drug-adulterated dietary supplement is actually a falsified drug, we discuss its main contributing factors. Then, we describe some examples of adverse events of which a case of sildenafil-tadalafil-induced ischaemic stroke that benefited medical care in our hospital. Furthermore, we present some means to avoid adulteration and discuss their limitations that may be explained by the heterogeneity of the regulation of dietary supplements between countries. Doing so, we point out the requirement of a global harmonization of this regulation for an efficient eradication of this public health threat. Meanwhile, dietary supplements should be considered adulterated until proven otherwise. Thus, we encourage physicians to investigate these products in the drug histories of their patients, especially when clinical conditions cannot be explained by classical aetiologies.

Role of nicotinic acid and nicotinamide in nicorandil-induced ulcerations: from hypothesis to demonstration.

Nicorandil, a nicotinamide ester, was first reported to be involved in the induction of oral ulcers in 1997. Since then, many reports of single or multiple nicorandil-induced ulcerations (NIUs) have been reported. We hypothesised that in the case of high-dosage nicorandil or after an increased dosage of nicorandil, nicotinic acid and nicotinamide (two main metabolites of nicorandil) cannot appropriately merge into the endogenous pool of nicotinamide adenine dinucleotide/phosphate, which leads to abnormal distribution of these metabolites in the body. In recent or maintained trauma, nicotinamide increases blood flow at the edge of the raw area, inducing epithelial proliferation, while nicotinic acid ulcerates this epithelial formation, ultimately flooding the entire scar. We demonstrate, by comparison to a control patient non-exposed to nicorandil, an abnormal amount of nicotinic acid (×38) and nicotinamide (×11) in the ulcerated area in a patient with NIUs. All practitioners, especially geriatricians, dermatologists and surgeons, must be aware of these serious and insidious side effects of nicorandil. It is critical to rapidly reassess the risk-benefit ratio of this drug for any patient, and not only for those with diverticular diseases.