Various toxicities: 4 case reportsA study of ten adult rheumatoid arthritis (RA) female patients described four women, aged 27-63 years, who developed irritability, nausea, vomitting, elevated liver enzymes, gastrointestinal upset or fatigue during treatment with methotrexate for RA. Additionally, two of these women exhibited lack of efficacy during treatment with methotrexate for RA [routes, dosages, durations of treatments to reactions onsets and outcomes not stated].Patient 1: The 49-year-old woman, who had RA, started receiving methotrexate. Thereafter, she developed irritability, nausea, vomiting and elevated liver enzymes due to methotrexate. She showed SLCO1C1 gene polymorphism, and the treatment with methotrexate was found to be effective.Patient 3: The 49-year-old woman, who had RA, started receiving methotrexate. Thereafter, she developed nausea and vomiting due to methotrexate. She showed ATIC gene polymorphism, and the treatment with methotrexate was found to be ineffective for RA (lack of efficacy).Patient 8: The 63-year-old woman, who had RA, started receiving methotrexate. Thereafter, she developed gastrointestinal upset, nausea and vomiting due to methotrexate. She showed ABCB1 gene polymorphism, and the treatment with methotrexate was found to be effective.Patient 9: The 27-year-old woman, who had RA, started receiving methotrexate. Thereafter, she developed nausea and fatigue due to methotrexate. She showed ATIC gene polymorphism, and the treatment with methotrexate was found to be ineffective for RA (lack of efficacy).