Sildenafil-associated hepatoxicity: a review of the literature

Sildenafil citrate (Viagra®) is a vasoactive agent available worldwide since 1998 for the treatment of male erectile dysfunction. It is a selective phosphodiesterase type 5-enzyme inhibitor able to potentiate the downstream effects of nitric oxide on smooth muscle relaxation and vasodilation through its effects on the cyclic guanosine monophosphate (c-GMP) pathway in the erectile tissue of the penis. When sildenafil is orally administered, it is rapidly absorbed with a maximum plasma concentration achieved within 1 h and has a terminal half-life of between 3 to 6 h. The drug is extensively and rapidly metabolized by the liver, primarily by the CYP3A4 enzyme. Although the drug is well tolerated, specific adverse events have been observed, like flushing, headaches, dyspepsia, and visual disturbances. Liver toxicity related to sildenafil consumption has been considered a very rare event. However, in the last decade, some cases of sildenafil-associated hepatotoxicity have been reported. Furthermore, some hepatic intoxications have been reported after the intake of "natural" or "herbal" aphrodisiac supplements sold through Internet, sex shops, social media, and by word-of-mouth found to contain sildenafil and other phosphodiesterase type 5 (PDE-5) inhibitors. Studies investigating a possible link between sildenafil use and liver damage are limited, and the underlying mechanism responsible for hepatotoxicity is still missing. Studies in animals evidence that the hematopoietic function of the liver may have severely been affected as a result of a probable toxic effect of sildenafil. Here, the studies reporting liver toxicity by sildenafil in humans and in animals are reported and discussed.

Hepatotoxicity associated with illicit use of anabolic androgenic steroids in doping

Anabolic Androgenic Steroids (AAS) abuse and misuse is nowadays a harmful habit involving both professional or recreational athletes, as well as general population. AAS are also frequently present in over-the-counter dietary supplements without being declared in the list of ingredients, leaving consumers unaware of the risks of adverse effects. Indeed, health risks of AAS consumption in pharmaceutical preparations or dietary complements seem still underestimated and under-reported. The variety of complications due to AAS misuse involves cardiovascular, central nervous, musculoskeletal and genitourinary systems of both males and females; psychiatric and behavioral effects, damages to metabolic system, skin and mainly liver. For instance, relevant concern has been raised by the AAS hepatotoxicity including adenoma, hepatocellular carcinoma, cholestasis, and peliosis hepatis. The present review reports the information available on the hepatotoxic effects of AAS use in professional and amateur athletes.

Hepatotoxicity associated to synthetic cannabinoids use

Synthetic cannabinoids (SCs) are psychotropic compounds, chemically created in laboratory to mimic cannabinergic brain activity of delta-9 tetrahydrocannabinol. The consumption of these compounds for recreational purposes can lead to a variety of adverse effects on health including overdose and deaths. Increasingly popular as substances of abuse since the 2000s, SCs were produced initially to bind and study cannabinoid receptors (they also can be called synthetic cannabimimetics) failing in eliminating the psychoactive effects. Currently, SCs are misused by students and young adults as "natural products" because of their herbal aspect. Actually, these apparently innocuous recreational substances hide toxic effects to health. Reported side effects are cardiovascular, gastrointestinal, neurological, renal, metabolic, ophthalmologic, pulmonary and psychoactive including dependence and withdrawal. A few cases of SCs ingestion have also been associated with liver failure. We herein review the recent literature on the SCs toxicity with particular attention to liver damage aspects.

Optimized conditions for simultaneous determination of opiates, cocaine and benzoylecgonine in hair samples by GC–MS

The present paper describes a qualitative and quantitative method for the simultaneous detection of opiates, cocaine and benzoylecgonine from human hair samples. Every step of the analytical procedure was studied to find the optimized conditions. Nine different incubation systems were examined. The influence of different pH values of samples on the isolation of analytes from the incubation media by Bond Elut cartridges and the stability of the compounds of interest in the different incubation media and conditions were investigated. The extracting power of different incubation media was studied as well. The phosphate buffer 0.1 N at pH 5 was chosen as the extraction medium in an optimized procedure for simultaneous determination of opiates, cocaine and benzoylecgonine in hair samples. The method developed was validated. Recoveries were 90% for morphine (M), 81% for 6-monoacetylmorphine (6-AM), 90% for codeine (CD), 86% for cocaine (C) and 90% for benzoylecgonine (BE). Relative standard deviation for inter-day precision was better than 12%. The limits of detection resulted as 0.05 ng/mg for M and C, as 0.08 for 6-AM and as 0.2 ng/mg for BE. Forty hair samples collected from drug abusers admitted to centers for detoxification treatment were analyzed obtaining 23 positive results for opiates and/or cocaine. Twelve hair specimens longer than 10 cm were analyzed following a sectional approach. In the six positive cases, it was interesting to find that the 6-AM/M ratio generally decreased for each sample from the proximal segment to the distal segments. Moreover, the 6-AM/M ratio was generally lower than 1 in the intermediate and distal segments.