Nakafero et al reported a prognostic model for predicting the risk of methotrexate toxicity in a patient with an immunologic disorder. This can help to identify a patient who may require more aggressive management or an alternative therapy. The authors are from multiple institutions in England.
Patient selection: adult >= 18 years treated with methotrexate for an immune-mediated inflammatory disorder
Exclusions: CKD Stage 4 o 5, severe chronic liver disease, severe hematological disease
Parameters:
(1) methotrexate daily dose in mg
(2) age in years at first primary care prescription
(3) sex
(4) body mass index (BMI)
(5) smoking status
(6) alcohol intake
(7) psoriasis or psoriatic arthritis
(8) polymyalgia rheumatica or giant cell arteritis
(9) other connective tissue disease
(10) spondyloarthritis, reactive arthritis or inflammatory bowel disease
(11) diabetes
(12) chronic kidney disease
(13) therapy with hydroxychloroquine
(14) therapy with 5-aminosalicylate or sulfasalazine
(15) therapy with other glucocorticoid sparing agent
(16) therapy with statin
(17) therapy with NSAID or high dose aspirin
(18) therapy with paracetamol/acetaminophen
(19) therapy with proton pump inhibitor
(20) therapy with antiepileptic
(21) cytopenia or raised liver enzymes <= 6 months after first methotrexate prescription (early adverse effects
|
Parameter |
Finding |
Points |
|
methotrexate daily dose |
|
0.0111752 * (dose) |
|
age in years |
|
-0.0005886 * (age) |
|
sex |
male |
0 |
|
|
female |
-0.0412595 |
|
body mass index |
|
-0.0100983 * (BMI) |
|
smoking status |
never or former |
0 |
|
|
current |
0.0545787 |
|
alcohol intake |
none |
0 |
|
|
low |
-0.0745235 |
|
|
moderate |
-0.2376144 |
|
|
hazardous |
0.1062592 |
|
|
former |
-0.0555338 |
|
psoriasis/psoriatic arthritis |
no |
0 |
|
|
yes |
0.1339634 |
|
polymyalgia or GCA |
no |
0 |
|
|
yes |
-0.0111359 |
|
connective tissue disease |
no |
0 |
|
|
yes |
0.2919058 |
|
spondyloarthritis, etc |
no |
0 |
|
|
yes |
0.2636568 |
|
diabetes |
no |
0 |
|
|
yes |
0.2225364 |
|
chronic kidney disease |
none |
0 |
|
|
Stage 1 or 2 |
0 |
|
|
Stage 3 |
0.7005654 |
|
hydroxychloroquine |
no |
0 |
|
|
yes |
-0.1073611 |
|
sulfa drug |
no |
0 |
|
|
yes |
-0.0791611 |
|
other GC sparing drug |
no |
0 |
|
|
yes |
0.1000699 |
|
statin |
no |
0 |
|
|
yes |
0.1021201 |
|
NSAID or aspirin |
no |
0 |
|
|
yes |
-0.0334514 |
|
acetaminophen |
no |
0 |
|
|
yes |
0.1608563 |
|
proton pump inhibitor |
no |
0 |
|
|
yes |
0.0170423 |
|
antiepileptic |
no |
0 |
|
|
yes |
0.516347 |
|
early adverse effects |
none |
0 |
|
|
cytopenia |
1.086389 |
|
|
elevated liver function tests |
1.086389 |
|
|
both |
1.086389 |
score =
= SUM(points for all of the parameters)
value of X =
= EXP(0.93 * (score))
risk score for methotrexate toxicity =
= 1 - (0.895 ^ X)
Performance:
• The area under the ROC curve was 0.66.
Specialty: Toxicology, Pharmacology, clinical, Emergency Medicine
