Acute Methotrexate Toxicity: A Fatal Condition in Two Cases of Psoriasis

Abstract

We describe two fatal cases of low dose methotrexate (MTX) toxicity in patients with psoriasis, emphasizing the factors that exacerbate MTX toxicity. The first patient was a 50-year-old male of psoriasis on intermittent treatment with MTX. After a treatment-free period of six months, he had self-medication of MTX along with analgesic for joint pain for one week which followed ulceration of the lesions, bone marrow suppression, and eventually death. The second patient was a 37-year-old male of psoriasis, who has taken MTX one week earlier without prior investigations. He had painful ulcerated skin lesions and bone marrow suppression. On investigations, he showed high creatinine level and atrophied, nonfunctioning right kidney on ultrasonography. In spite of dialysis, he succumbed to death. MTX is safe and effective if monitored properly, but inadvertent use may lead to even death also. Prior workup and proper counseling regarding the drug interactions as well as self-medication should be enforced.

Mucocutaneous Ulcerations and Pancytopenia due to Methotrexate Overdose

“…Previous publications report a complete recovery within 10 days of stopping MTX [4]. However, cases with a fatal outcome after MTX-induced ulcerations and pancytopenia have also been described [4, 8]. …”

“…It can be displaced by other medications with high plasma protein binding. For example, concomitant ingestion of NSARs, sulfonamides, retinoids, tetracyclines and salicylates raises serum levels of MTX [3, 8]. MTX is mainly excreted by glomerular filtration in the kidneys, only a minor portion is metabolized in the liver [2].…”

“…Simultaneous administration of other medications that affect renal function may also interfere with MTX elimination. For example, NSAIDs, several antibiotics, sulfonamides and probenecid might lead to MTX accumulation in that way [8]. To detect MTX-induced organ toxicity at an early stage, monitoring of the blood cell count and of the liver enzymes is recommended at 1, 2, 3, 4, 5 and 12 weeks, and then every 3 months [9].…”

A case of methotrexate intoxication in a patient with psoriasis who drank beetroot juice during methotrexate treatment

“…Methotrexate toxicity is manifested by AEs such as diarrhoea, gastrointestinal bleeding and ulcers, pancytopenia, anagen effluvium, erosions of the oral mucosa and, as was the case in our patient, ulcerations on psoriatic plaques. Restriction of the ulcerations to the psoriatic plaques may be related to their higher uptake of methotrexate compared with normal skin …”

“…Methotrexate is safe and effective in the treatment of psoriasis if its use is monitored carefully; otherwise, intoxication may ensue. Cutaneous lesions are usually the first sign of methotrexate toxicity . We present the case of a 50‐year‐old woman who developed methotrexate intoxication after drinking beetroot juice.…”