Thiamine deficiency and oxidative stress induced by prolonged metronidazole therapy can explain its side effects of neurotoxicity and infertility in experimental animals: Effect of grapefruit co-therapy.

We aimed to explore the possible neurotoxicity and infertility mechanisms of prolonged metronidazole (MTZ) use and the effects of antioxidant grapefruit (GP) co-therapy on MTZ-induced complications. Sixty male albino Wistar rats were divided into four groups (n = 15 each). Group I (control group) received 1% dimethyl sulfoxide (27 ml/ kg/day), group II (MTZ group) received MTZ (400 mg/kg/day), group III (MTZ + GP) received MTZ (400 mg/kg/ day) plus GP juice (27 ml/kg/ day) and group IV (GP group) received GP juice (27 ml/kg) for 60 days. Semen analyses were performed. Free testosterone, gonadotrophin (follicle-stimulating hormone (FSH) and luteinizing hormone) and thiamine levels were measured. Samples of cerebellar, testicular and epididymal tissues were used for both colorimetric assays of oxidative stress markers and histopathological examinations. Significant decreases in the sperm count, percent total sperm motility, serum thiamine levels, free testosterone levels and FSH levels were observed in the MTZ and MTZ + GP groups (p < 0.05 for all parameters). Significantly higher oxidative stress levels (p < 0.05) were observed in the cerebellar and testicular tissue homogenates of these groups than in those of the control group, and associated disruptions in the cerebellar, testicular and epididymal structures were apparent compared to those of the control group. Although the GP group showed a significantly higher sperm count and significantly lower oxidative stress than the control group (p < 0.05), with histological similarity to the control group, the GP group exhibited significantly higher prolactin levels and lower free testosterone and FSH levels than the control group (p < 0.05). Oxidative stress and decreased thiamine levels could explain the MTZ-induced neurotoxicity and infertility side effects that aggravated by GP co-administration.

Antibiotic prophylaxis of infective endocarditis in oral and maxillofacial surgery: incomplete implementation of guidelines in everyday clinical practice.

Infective endocarditis (IE) is a devastating disease with high mortality. Most guidelines recommend routine use of antibiotic prophylaxis during oral surgery to prevent IE in patients with specific predisposing cardiac conditions, but this is not the case in the UK. The conflicting opinions and guidance are confusing and may affect IE prophylaxis implementation. We investigated how IE prophylaxis standards are defined in hospitals and outpatient clinics of oral and maxillofacial surgery. A survey was sent to 80 surgeons heading departments of oral and maxillofacial surgery in Germany. We observed significant heterogeneity in IE prophylaxis implementation among the clinics. This diversity was in relation to the definition of predisposing cardiac conditions, the type of dental and surgical procedures performed that require IE prophylaxis, the spectrum of compounds used, and the timing of antibiotic prophylaxis. We observed under-prescription of IE prophylaxis in high-risk patients, the overuse of antibiotic prophylaxis in patients not at high risk of IE, and the use of inappropriate drugs. These findings suggest that educational strategies and guideline implementation advice are needed to improve standards of IE prophylaxis in oral and maxillofacial surgery clinics.