Methotrexate – A double edged sword Dr.Yogesh kalyanpad,
Department of dermatology, Seth G.S.M.C.&K.E.M.Hospital
Severe clinical manifestations of toxicity : Mucositis Stomatitis Esophagitis Acute Renal failure Myelosuppression Neurologic dysfunction Erosions all over body specially
on psoriatic plaques Diarrhea
RISK FACTORS FOR METHOTREXATE TOXICITY :
1. Increased Free plasmatic levels due to:
• Displacement of protein bound methotrexate by other drugs : sulfonamides , tetracycline, aspirin, phenytoin
• Displacement by protein deprivation
2. Renal elimination decreased:• Old age• Pre-existing renal failure• Drugs : salicylates,
cyclosporinA, colchicine, sulfonamides.
Physician level-
1. Inadequate counselling about drug dosage
2.Lack of re-emphasis about weekly dosage system
3. Use of confusing brand names(eg –metz=metoprolol)
Medication errors during methotrexate toxicity
Patient level-
•Confusion among various drugs•Misinterpretation about dosage•Daily methotrexate and weekly folic acid•For faster relief self administration of larger dosage•Forgetfulness of ingested dosage in old patients
Pharmacy-
1. Modification of dosage prescribed
2. Over the counter availability
Other-
Idiosyncrasy reaction
Mistakes while taking some tablet forms
Can be simply prevented by converting into
Daily pill container
box
Prevention is better than cure
• Involvement of close relative during counselling • Initiate with small dose with gradual escalation• Creating awareness among patient as well
relatives about possible side effects • Use of supervised injectable forms of
methotrexate
Thank you