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