5PSQ-065 Prediction of toxicity of methotrexate by means of genetic tests in patients diagnosed with moderate–severe psoriasis

• Published in: European journal of hospital pharmacy. Science and practice Vol. 27; no. Suppl 1; pp. A179 - A180
• Main Authors: Membrive, C, Perez Ramírez, C, Márquez Pete, N, Maldonado Montoro, MDM, Arias Santiago, SA, Jimenez Morales, A, Ramirez Tortosa, MDC
• Format: Journal Article
• Language: English
• Published: London BMJ Publishing Group LTD 01-03-2020
• Subjects: Alcoholism; Diabetes; Health risk assessment; Psoriasis
• ISSN: 2047-9956; 2047-9964
• DOI: 10.1136/ejhpharm-2020-eahpconf.382

Background and importanceMethotrexate is the standard treatment for moderate–severe psoriasis. However, it is a very aggressive treatment which has a high percentage of severe adverse events, such as asthenia, gastrointestinal toxicity, haematological toxicity and nephrotoxicity. This toxicity profile varies from person to person. Various studies have reported that these interindividual differences may be due to genetic factors, such as single nucleotide polymorphisms (SNPs), which are involved in methotrexate pharmacodynamics, metabolism and mechanism of action.Aim and objectivesTo determine the utility of ABCB1 C3435T and MTHFR 1298 as prognostic and predictive markers in patients diagnosed with moderate–severe psoriasis treated with methotrexate, and to evaluate the toxicity of methotrexate treatment.Material and methodsA prospective cohort study was performed. Data and DNA were obtained from saliva samples of 64 patients residing in the province of Granada with moderate–severe psoriasis who had been treated with methotrexate. The genotypes were determined by Taqman PCR real time.ResultsMean age of the patients was 46±14 years; 33 men (33/64); 57 had psoriasis plaque (57/64), 56 located in the trunk and extremities and 30 in the scalp and face, 17 had psoriatic arthritis (29/64), 7 with diabetes mellitus (7/64), there were 19 smokers (19/64), 16 occasional drinkers (16/64) and 30 had a family history of psoriasis (30/64). Twenty-eight patients were treated with oral administration of methotrexate (28/64) and 44 for <12 months (44/64). Thirty patients were high responders (30/64), 34 presented with gastrointestinal toxicity (34/64), 25 hepatic toxicity (25/64) and 12 skin toxicity (12/64).An association between nausea and alcoholism (p=0.06), diarrhoea and diabetes mellitus (p=0.03), age (p=0.02) and treatment duration (p=0.01) was found. Furthermore, a relationship between vomiting and female gender (p=0.016) and smoking (p=0.017) was observed.No significant association was found between toxicity and the MTHFR 1298 and ABCB1 C3435T polymorphisms examined.Conclusion and relevanceIn conclusion, gastrointestinal toxicity events were associated with alcoholism, diabetes mellitus, age, treatment duration, female gender and smoking. No significant association was found between toxicity and the SNPs examined.References and/or acknowledgementsNo conflict of interest.