Methotrexate Monitoring in Dermatology Journal of Drugs in Dermatology

TAKE-HOME MESSAGE

• This University of Virginia Health System retrospective analysis of lab monitoring included 243 dermatology patients (56% female) during the first 90 days of methotrexate therapy for psoriasis (67.1%), eczematous disease (17.3%), autoimmune connective tissue disease (4.5%), or other disease (11%). In total, 309 abnormal lab values were collected, with 18% (n = 57) of these resulting in a clinically relevant event (CRE) such as decreased dose (n = 11), drug discontinuation (n = 22), repeat lab testing (n = 20), or continuation of the same dose when the provider had intended to increase it (n = 4). Increased odds of developing CRE were seen with heart failure (OR, 5.5; P = .03), chronic kidney disease (OR, 9.0; P = .03), and baseline low platelets (OR, 9.3; P = .008). Although high AST and low hemoglobin were the most common lab abnormalities, high ALT, low absolute lymphocyte count, and low absolute neutrophil count were most likely to be associated with a CRE.

• Less than 1% of labs drawn in the first 14 days of therapy led to discontinuing or decreasing the dose of methotrexate. The authors conclude that, in the absence of any concerning baseline characteristics, dermatologists can wait to repeat labs until 15 to 30 days after initiating treatment; this time period is more similar to the generally less stringent rheumatology guidelines on methotrexate monitoring.

– Caroline K. Crabtree, MD

Written by

 

 

Warren R. Heymann MD

Monitoring for methotrexate (MTX) toxicity is of paramount importance. Although the use of MTX for psoriasis has diminished with the advent of biologics, it is still a valuable drug for dermatologists treating psoriasis and autoimmune diseases.

Monitoring guidelines are mostly based on expert opinion. Please refer to the "Joint American Academy of Dermatology–National Psoriasis Foundation Guidelines of Care for the Management of Psoriasis With Systemic Nonbiologic Therapies" (J Am Acad Dermatol. 2020;82(6):1445-1486) for current consensus monitoring recommendations for MTX—initial baseline screening, laboratory monitoring during therapy, and considerations for long-term follow-up of hepatotoxicity.

From my perspective, the baseline assessment is crucial. What disease are we treating? Is it a young, healthy patient with psoriasis? Is it a psoriatic patient with obesity, with a prior history of hepatitis, who enjoys drinking with his buddies on the weekend? Does the patient have lupus with a history of thrombocytopenia? A thorough baseline assessment of comorbidities gives the clinician a sense of risk and may determine how carefully to follow laboratory studies based on dose escalation. Be advised that many practitioners are now starting patients at a therapeutic dose of MTX in healthy patients, while using a test dose with small dose increases for those with multiple comorbidities.

This study revealed that a diagnosis of congestive heart failure, chronic kidney disease, and an initial low platelet count increased the odds of developing a clinically relevant event at some point during MTX therapy. In the first 15 days following MTX initiation, only 1/114 lab draws (0.9%) resulted in discontinuation of the medicine, 1/114 (0.9%) resulted in maintenance of a stable dose, and 2/114 (1.8%) resulted in repeat laboratory testing. The authors concluded that, in the absence of concerning baseline patient characteristics, dermatologists may consider postponing initial lab monitoring until 15 days post MTX initiation.

This is a valuable contribution, if corroborated by future studies. For our patients' sake, it would be optimal to minimize testing for patient convenience and cost to the healthcare system. Until such guidelines are de rigueur, the art of laboratory monitoring in the first 90 days of therapy will prevail, until the science dictates otherwise.

Abstract

BACKGROUND AND OBJECTIVES

There are currently no evidence-based recommendations to guide lab monitoring in the first 90 days of methotrexate treatment. The purpose of this study was to determine whether certain monitoring practices or baseline patient characteristics were associated with increased risk of developing clinically meaningful lab abnormalities during the course of methotrexate treatment. 

PATIENTS AND METHODS

This retrospective cohort study analyzed 243 dermatologically managed patients taking methotrexate at the University of Virginia Health System. Odds ratios were used to analyze the risk of these patients developing lab abnormalities that result in a change in clinical management, referred to as clinically relevant events. Chi-square analysis was used to determine the optimal timing of methotrexate lab monitoring. 

RESULTS

A diagnosis of congestive heart failure (P=0.03), chronic kidney disease (P=0.03), and an initial low platelet count (P=0.008) increased the odds of developing a clinically relevant event at some point during methotrexate therapy. In the first 15 days following methotrexate initiation, only 1/114 (0.9%) lab draws resulted in discontinuation of the medicine, 1/114 (0.9%) resulted in maintenance of a stable dose, and 2/114 (1.8%) resulted in repeat laboratory testing. 

CONCLUSION

In the absence of concerning baseline patient characteristics, dermatologists may consider postponing initial lab monitoring until 15 days post methotrexate initiation.

Journal of Drugs in Dermatology

Methotrexate Monitoring in Dermatology—A Retrospective Cohort Study

J Drugs Dermatol 2021 Mar 01;20(3)5790, AG Zufall, RH Flowers, MM Noland, B Rama, EK Ninmer, SL Vittitow, M Saito

Sent from my iPhone

Benjamin Hidalgo-Matlock
Skin Care Physicians of Costa Rica

Clinica Victoria en San Pedro: 4000-1054
Momentum Escazu: 2101-9574

Please excuse the shortness of this message, as it has been sent from
a mobile device.