A Nigerian pharmacist and researcher, Oyinlade Kehinde, has made a groundbreaking discovery about why the same drugs affect individual patients differently, with a mission to change how doctors prescribe mental health drugs for African patients.
Kehinde, a PhD student at the University of Florida and former Assistant Director of Pharmacy at the Federal Neuro-Psychiatric Hospital, Yaba, Lagos, presented the findings during the 8th International Yaba Research Conference held at the hospital on Wednesday under the theme, ‘Artificial Intelligence in Mental Health Research’.
Her study, titled ‘Closing the Health Inequity Gap: Impact of CYP2D6*17 and *29 Alleles on Risperidone Metabolism in an African Paediatric Population’, revealed that two genetic variants common among Africans alter how the body processes risperidone, a widely used antipsychotic drug.
According to her, the discovery shows that international drug guidelines based largely on European data may not give accurate dosing recommendations for African patients.
“Two patients could take the same mental health medication, yet one would get better while the other struggled with severe side effects.
That puzzle made me ask a simple question: why do people respond so differently to the same medicine?” Kehinde asked.
She said her curiosity was born from years of seeing patients and families struggle with unpredictable drug responses at the hospital, as doctors tried different medications in search of one that worked.
According to her, some families spent a lot of money and energy “trying different drugs, hoping to find one that worked, while doctors did their best but often felt frustrated.”
With limited opportunities to study pharmacogenetics in Nigeria, Kehinde said she joined the Pharmacogenomics Global Research Network to learn from experts around the world.
Through that network, she connected with other professionals like Dr Laura Ramsey of Children’s Mercy Hospital in Kansas and Dr Akinyemi Oni-Orisan of the University of California, San Francisco, who later became her co-investigators in the study.
Kehinde explained that the research focused on two genetic variants of the enzyme CYP2D6, known as *17 and *29, which are common among Africans but poorly represented in global research data.
“We discovered that CYP2D6*17 actually works faster than previously thought, while CYP2D6*29 may not work at all for breaking down risperidone. This means that using data from European studies alone could lead to incorrect dosing for African patients,” she said.
The pharmacist added that the study was the first and largest real-world investigation of African-specific CYP2D6 variants in risperidone metabolism among children and that the findings would be shared with international pharmacogenetic groups to help update global drug-dosing standards.
“Our research shows that genetics can behave differently depending on ancestry and even on the specific drug being used,” she said.
Kehinde said one of the most rewarding outcomes of the study was returning each child’s pharmacogenetic result to their medical record, allowing doctors to make better treatment decisions in the future.
“This ensures that children receive safer and more effective care, guided by science that truly reflects their genetic background,” she noted.
She described the project as a major step toward personalised psychiatry in Nigeria and across Africa, saying the ultimate goal was to ensure that every patient, regardless of origin, received the right medication at the right dose.
“Pharmacogenetic testing can be expensive, sometimes costing between $300 and $1,000 per person. Being able to carry out this kind of research locally is a big achievement,” she stated.
Kehinde appreciated the Medical Director of the Federal Neuro-Psychiatric Hospital, Dr Olugbenga Owoeye, as well as the pharmacy and laboratory departments, research assistants, and collaborators who contributed to the study.
She submitted, “Our findings were eye-opening. We discovered that the existing international guidelines, which help doctors interpret these genetic variants, don’t fully capture how they behave in African populations. We found that CYP2D6*17 actually works faster than previously thought, while CYP2D629 may not work at all for breaking down risperidone. This means that using data from European studies alone could lead to incorrect dosing for African patients. These results show that genetics can behave differently depending on ancestry and even on the specific drug being used.
“We plan to share our findings with global experts so that dosing guidelines can be updated to better include African genetic data and risperidone metabolism.”
