Methotrexat in der Rheumatologie

Real-world data on MTX tolerance with regimens used in children versus adults

OBJECTIVE

Methotrexate (MTX) is one of the most commonly used disease-modifying anti-rheumatic drugs which can cause gastrointestinal side effects. MTX intolerance is defined as gastrointestinal and behavioral symptoms occurring before and after MTX administration. This study aims to evaluate and compare the frequency of methotrexate intolerance in adult and pediatric patients.

METHODS

Patients with a rheumatic disease who used oral or parenteral methotrexate for at least 3 months were included in the study. Methotrexate intolerance was assessed using the Methotrexate Intolerance Severity Score (MISS) questionnaire and visual analog scale (VAS). In the pediatric patient group, the MISS questionnaire and VAS assessment were applied to both patients and families.

RESULTS

A total of 200 patients, 100 of whom were children, were enrolled in the study. The mean age for children and adults were 11.9 (± 3.7) and 52.0 (± 10.9). The prevalence of MTX intolerance was higher in the pediatric group, 64.0 and 10.0% (p < 0.001), respectively. Compared with oral administration, the patients receiving parenteral MTX had a higher proportion of MTX intolerance (p < 0.001). Younger age was the independent risk factor for MTX intolerance. There was a strong correlation between MISS and VAS scores between the evaluations of the patient and the family (p < 0.01, r = 0.95/p < 0.01, r = 0.94).

CONCLUSION

Methotrexate intolerance was higher in childhood. All patients using MTX should be monitored and questioned for signs of intolerance.

Frequency of methotrexate intolerance in rheumatoid arthritis patients using methotrexate intolerance severity score (MISS questionnaire)

The objective of the study was to determine the frequency of methotrexate intolerance in rheumatoid arthritis (RA) patients by applying the methotrexate intolerance severity score (MISS) questionnaire and to see the effect of dose and concomitant use of other disease-modifying antirheumatic drugs (DMARDS) on methotrexate (MTX) intolerance. For the descriptive study, non-probability sampling was carried out in the Female Rheumatology Department of Fauji Foundation Hospital (FFH), Rawalpindi, Pakistan. One hundred and fifty diagnosed cases of RA using oral MTX were selected. The MISS questionnaire embodies five elements: abdominal pain, nausea, vomiting, fatigue and behavioural symptoms. The amplitude of each element was ranked from 0 to 3 being no complaint (0 points), mild (1 point), moderate (2 points) and severe (3 points). A cut-off score of 6 and above ascertained intolerance by the physicians. A total of 33.3 % of the subjects exhibited MTX intolerance according to the MISS questionnaire. Out of which, the most recurring symptom of all was behavioural with a value of 44 % whereas vomiting was least noticeable with a figure of 11 %. About 6.6 % of the women with intolerance were consuming DMARDs in conjunction with MTX. Those using the highest weekly dose of MTX (20 mg) had supreme intolerance with prevalence in 46.2 % of the patients. The frequency of intolerance decreased with a decrease in weekly dose to a minimum of 20 % with 7.5 mg of MTX. MTX intolerance has moderate prevalence in RA patients and if left undetected, the compliance to use of MTX as a first-line therapy will decrease. Methotrexate intolerance is directly proportional to the dose of MTX taken. Also, there is no upstroke seen in intolerance with the use of other disease-modifying agents.

[Personalized medicine in the choice of conventional immunosuppressants and disease modifying antirheumatic drugs]

The decision for a certain therapy for autoimmune diseases is influenced by various factors. These include well-defined arguments, such as approval of the drug for a certain disease, data from studies or registries, age and gender, family planning, risk for infections of the specific patient, side effects, price, data on the importance of genetic polymorphisms for tolerance and effectiveness of the drug or preferences in the way the drug is administered. On the other hand there are less definable factors which influence the choice of a certain drug, such as the mode of action and possibility to combine it with other drugs as well as individual preferences and experiences of patients and rheumatologists. As in the diagnostic procedure of complex rheumatologic diseases the discussion of the differential indications of a drug in the specific situation requires a mosaic-like assembly of many factors and aspects which argue for or against a certain drug in the individual patient, disease and situation. It would be desirable if definable factors were already available which could be recruited as substantial arguments pro or contra a drug in the sense of personalized medicine. This could improve the tolerance and effectiveness of therapeutic strategies. However, as this is not yet the case the authors have tried to assemble ideas which might argue pro or contra conventional disease modifying antirheumatic drugs (DMARD) and immunosuppressive drugs.

Prediction of adverse events by in vivo gene expression profiling exemplified for phytopharmaceuticals containing salicylates and the antidepressant imipramine

BACKGROUND AND OBJECTIVE

Gene expression profiles of Sprague-Dawley (SD) rats treated with a standardized willow bark extract (WB), its salicin rich ethanol fraction (EtOH-FR) or the tricyclic antidepressant imipramine were evaluated for their potential to induce adverse events. Treatments had shown antidepressant-like effects.

METHODS

Gene expression profiles (Agilent Whole Genome Array, n=4/group) obtained from the peripheral blood of male SD rats treated with WB (STW 33-I), EtOH-FR (30 mg/kg bw) or imipramine (20 mg/kg bw) were analysed comparatively by the Ingenuity Systems Programme, which allows to conduct model calculations of thresholds for theoretical potential adverse events (AE).

RESULTS

The number of genes regulated by the three treatments were 1673 (WB), 117 (EtOH-FR) and 1733 (imipramine). The three treatments related to 47 disease clusters. The WB extract reached the threshold for a potential AE in one disease cluster (cardiac hypertrophy), whereas the EtOH-FR exceeded the threshold in 5 disease clusters (cardiac arteriopathy and stenosis, glomerular injury, pulmonary hypertension, alkaline phosphatase levels ⇑). Imipramine treatment hit 13 disease clusters: tachycardia, palpitation, myocardial infarction, arrhythmias, heart block, precipitation of congestive heart failure; urinary retention, altered liver functions. Those correspond to known potential adverse events. Glomerular injury and altered liver functions are part of the side effect profile of salicylic acid derivatives in agreement with the findings for the salicin rich EtOH-FR.

CONCLUSION

There is no linear relationship between the number of constituents of a drug (preparation) and the number of different targets hit in a biological system on the gene expression level. Therefore, the number of genetic targets in a biological system does not necessarily increase with the complexity of the treatment corresponding to the non-linear behaviour of biological systems. Regarding gene expression levels AE of single treatments are not necessarily additive in combination treatments. The applied method appears to be an interesting screening tool for the prediction of potential AE. The phenomena that imipramine crossed the potential threshold for AEs several times whereas the WB extract did reach the threshold level only once, however not backed by clinical data for this AE, deserves to be further investigated. It questions the commonly assumed principle that substances with low number or without AE will have a poor efficacy.

[Pharmacogenetics and pharmacogenomics of methotrexate. Current status and novel aspects]

Since its introduction as a disease-modifying drug, methotrexate (MTX), a folate antagonist, is regarded as a major pillar of anti-rheumatic pharmacotherapy. This has not been changed in the current era of biologicals based on recombinant proteins. Despite most promising therapeutic progress about half of rheumatoid arthritis patients still display insufficient response to anti-rheumatic drugs. Specifically, about one in four patients on MTX shows lack of sufficient therapeutic efficacy which may lead to drug discontinuation. In addition, adjustment of therapy may be necessary due to individual drug toxicity. In this context and in light of recent advances concerning the use of genetic analysis in clinical practice, the development of novel strategies which implement individualized pharmacotherapy has become a major issue for translational and clinical research. Accordingly, numerous studies have been performed in recent years analyzing genetic polymorphisms of cellular parameters which relate to MTX efficacy and toxicity. Data currently available demonstrate the potential and the limitations of clinical genetic polymorphism analyses.