Experts have raised concerns over the simultaneous use of sildenafil citrate, commonly used to treat erectile dysfunction, and popular herbal alcoholic bitters, after researchers observed significant changes in liver, kidney and reproductive hormone markers in male laboratory rats.
The study, published in the West African Journal of Pharmacy, examined the effects of sildenafil citrate administered alongside three herbal bitters – Orijin, Action and Coco Samba – amid the widespread use of herbal preparations and alcoholic bitters.
There has been a shift in the consumption of beer towards alcoholic bitters, which are rich blends of medicinal roots and herbs and are widely used in Nigeria because of their various acclaimed health benefits.
Users of bitters often believe that the herbal preparations contain substances that cleanse the body, have anti-malarial and anti-diabetic properties, boost male virility, lower cholesterol levels and are non-toxic to the kidneys.
Erectile dysfunction has also been reported to be increasingly common among young men in Nigeria. Sildenafil citrate (Viagra) is one of the approved orthodox medicines used in the treatment of erectile dysfunction.
With the widespread acceptance of alcoholic bitters for their purported health and aphrodisiac benefits, men experiencing erectile dysfunction may combine herbal alcoholic bitters with sildenafil citrate.
In the study, the researchers found significant increases in alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea, luteinising hormone (LH) and testosterone across the experimental groups compared with the control group, indicating possible changes in liver, kidney and reproductive hormone function.
Elevated levels of ALT and AST can be associated with liver-cell injury or stress, although they are not specific to a particular cause. Increased urea and creatinine levels may indicate changes in kidney function, while LH is involved in signalling to the testes and testosterone is the principal male sex hormone.
The study, titled ‘Effect of concomitant administration of sildenafil citrate and selected herbal bitters on sex hormones and some biochemical indices in Wistar rats,’ was conducted by researchers from Olabisi Onabanjo University and Babcock University in Ogun State. It was in West African Journal of Pharmacy.
The researchers used 40 healthy adult male Wistar rats weighing between 115gm and 125gm. Following five days of acclimatisation, the animals were randomly divided into eight groups of five.
One group served as the control, while another received sildenafil citrate. Three groups received Orijin, Action or Coco Samba bitters, respectively, while the remaining three groups received sildenafil citrate in combination with each of the three bitters.
The substances were administered orally for 42 days. At the end of the experiment, blood samples were collected and analysed for markers associated with liver and kidney function, as well as testosterone and LH levels.
The researchers reported statistically significant differences in AST and ALT between the experimental animals and the control group.
According to the researchers, the elevation of AST and ALT in animals exposed to sildenafil, herbal bitters and their combinations could indicate liver injury.
The study also found significant differences in serum urea levels between the experimental groups and the control group.
The researchers reported a significant increase in creatinine, particularly among the animals that received Coco Samba alone and those that received Coco Samba together with sildenafil citrate.
They said the higher urea and creatinine levels could reflect impaired kidney function. They further described Coco Samba as having a potentially greater toxic effect on the kidneys than the other polyherbal formulations investigated.
However, the researchers acknowledged that increased urea levels can have other explanations, including dehydration and alcohol consumption.
Beyond the organ-function markers, the researchers observed significant increases in testosterone and LH among the experimental animals.
They suggested that increased LH could contribute to increased testosterone production and said the observed hormonal changes could be related to the combined effects of sildenafil and the phytochemical components of the herbal bitters.
Traditional herbal bitters, which are rich blends of medicinal roots and herbs, have been widely used in Nigeria because of their various claimed benefits.
Most herbal alcoholic bitters are also marketed with claims of improved sexual performance and stronger erections. Despite these claims and their widespread consumption, however, limited research has examined their safety and their purported effects on erectile function, particularly when used alongside conventional medicines.
Amid the widespread use of herbal preparations and alcoholic bitters, including products marketed with claims relating to sexual performance and male virility, awareness of the possible consequences of concomitant use of sildenafil citrate and herbal bitters remains limited.
The researchers noted that herbal medicines are often self-prescribed and may be taken alongside conventional medicines without healthcare professionals necessarily being informed about their use.
They further noted that herbal alcoholic bitters are marketed with various claims, including improving sexual performance, while limited research was available on their safety and claims concerning erectile function.
The research was conducted on Wistar rats, not human beings. Its findings therefore cannot by themselves establish that people who combine sildenafil with the herbal bitters will experience the same biochemical changes.
The study nevertheless provides experimental evidence of measurable biochemical and hormonal changes following concurrent exposure to sildenafil and the products investigated.
The researchers said the findings suggested possible effects on liver and kidney functions in the animals studied.
The findings underscore the importance of further investigation into the simultaneous use of prescription medicines and herbal alcoholic preparations, particularly products consumed for sexual-performance purposes.