Herbal medicinal products are becoming increasingly popular. At the same time, the safety issues related to herbal drugs continue to be ignored by the public, neglected by manufacturers and legislative bodies as well as under-researched by the medical professions.
One safety aspect that is of growing importance is that of herb-drug interactions, even though users of herbal medicines tend to believe that they are naturally safe.
Experts are warning that even the commonly consumed bitter kola should not be taken along side with many drugs, including malaria medicines and common antibiotics.
Experts’ assessment of the risk associated with taking quinine sulphate or other malaria medicines that contain quinine in them such as Arthemisin Combination therapy (ACT) alongside bitter kola, found it causes a reduction in the amount of the quinine that will be available in the blood stream to kill malaria germs.
ACT is currently the drug recommended by the Federal Ministry of Health for treating malaria, and some of them also contain quinine.
Bitter kola seed is chewed habitually for social reasons, for oral hygiene and as a masticatory agent in Africa. It is believed to possess many useful medicinal properties. It is usually used to treat throat infections, cough and stomach upset as well as an anti-stress agent.
In most parts of Nigeria, patients on antibiotic therapy and malaria medicines also chew bitter cola habitually or because of its traditionally acclaimed anti-infective properties.
Drugs are essential components of medical therapy but concomitant consumption of other substances with drugs can cause unintended and unwanted outcomes which may lead to significant harm in some cases.
The risk of drug interactions increases with number of drugs being taken by the patient. For example, the risk of interactions with six to 10 drugs may just be seven per cent but with 16 to 20 drugs, the risk may increase up to 40 per cent.
High risk patients, such as elderly patients taking three or more medications for chronic conditions are more susceptible to suffer from such interactions. Many of such patients also use herbs, fruits, vegetables and other nutrients due to their traditional and folk benefits.
This trial to ascertain the effect of ingesting bitter kola on the possible effective of quinine and other quinine containing malarial medicines involved 24 healthy Nigerian volunteers.
These were experts at the Obafemi Awolowo University, Ile-Ife, Nigeria in conjunction with their international collaborators. The 2015 study was in the Journal of Clinical Pharmacology and included Igbinoba Sharon , Onyeji CO, Akanmu MA, Soyinka JO, Pullela SS, Cook JM, and Nathaniel TI.
Previously demonstrated was the negative effect of ingesting kolanut alongside halofantrine, another antimalarial drug. Experts found that it causes a significant decrease in its effectiveness in treating malaria.
According to the experts, report in the 2008 edition of the European Journal of Clinical Pharmacology, caution should be exerted when the drug is taken together with caffeine-containing nutrients.
Ingesting bitter kola alongside antibiotics such as ciprofloxacin hydrochloride, abroad spectrum antibiotic to treat conditions such as typhoid fever, experts have also cautioned on, saying it was better avoided.
Studies in the laboratory showed the extract of bitter kola inhibit the antimicrobial properties of several antibiotics including gentamycin, tetracycline, co-trimoxazole, ciprofloxacin, ofloxacin, amoxicillin-clavulanic acid (AugmentinR) and penicillin G.
Previously in 2007, studies in 10 healthy male volunteers, aged between 20 and 30 years suggested that bitter kola impairs the bioavailability of ofloxacin by a binding itself to some chemical constituents of bitter kola, thus reducing its antimicrobial effectiveness.
Ofloxacin is an antibiotic used to treat common ailments like respiratory tract infections, upper and lower urinary tract infections and skin infections.