Friday, 19 Jan 2018

You are here

Low-dose Bactrim Safe with Methotrexate in AAV

A high proportion of GPA patients receive pneumocystis prophylaxis, usually with TMP-SMX (Bactrim), and drug interactions are always a concern.  

Given that many GPA patients are treated with methotrexate, we often wonder – can my patient safely receive TMP-SMX prophylaxis in conjunction with methotrexate? This concern exists because both methotrexate and TMP work by inhibiting dihydrofolate reductatse and thus it is not surprising that potential for bone marrow toxicity exists. Dr. Tamaki (Japan) presented an abstract this morning looking at safety of low dose TMP-SMX (160mg-800 mg 3x/week or 80mg-400mg/day) when given with methotrexate in patients with AAV.

They performed a retrospective chart review at the Cleveland Clinic (2002-2017) and compared variables between patients receiving methotrexate both with and without TMP-SMX and found the rates of methotrexate discontinuation to be similar between both groups with no differences in reasons for discontinuation (side effect, infection, switching to another medication to treat AAV, methotrexate withdrawal after sustained remission, patient discontinued). Side effects occurred in 8.6% of the methotrexate only group and 7.1% of the methotrexate + TMP-SMX group.

This Cleveland Clinic experience reassures us that it seems safe to administer methotrexate with low dose TMP-SMX, although close monitoring of these patients is key.  

 

Add new comment

More Like This

Prevention of HBV Infection: How Are We Doing?

In 2016 the WHO set out to eliminate HBV infection as a public health threat by 2030. So far, we are far from this goal as vaccine implementation has been suboptimal in a number of important patient populations, including patients with rheumatologic diseases, as well as other immunocompromising diseases like HIV.

B Cell Changes Predict Autoimmunity with Checkpoint Inhibitors

The Journal of Clinical Investigation reports results of a study showing that increases in CD21lo B cells and plasmablasts following that combination checkpoint blockade preceded the onset of immune-related adverse events.

While some have postulated that IRAEs are thought to be T cell mediated, B cells have also been implicated. Investigators studied 39 melanoma patients undergoing treatment with either anti-CTLA4 or anti-PD1, or combination CCB therapy. They analyzed changes in circulating B cells before and after the first cycle of therapy of immune checkpoint blockade (23 received combination therapy, 8 received anti-CTLA4, and 8 received anti-PD1).

Ibuprofen’s Anti-androgenic Effect May Result in Hypogonadism in Males

PNAS reports use of ibuprofen by males may result in antiandrogen effects that may contribute to adult male reproductive problems.

Sorting Out the Complexities of Autoimmunity with Immune Checkpoint Inhibitor Therapy

An editorial and systematic review of complications seen when checkpoint inhibitor (CPI) therapies are given to patients with immune mediated inflammatory disorders (IMIDs) and cancer shows that nearly 75% manifest autoimmune and inflammatory immune-related adverse events (irAEs).

Baseline Risk Score Predicts Serious Infection Risk in TNF-Treated RA Patients

Curtis and colleagues have analyzed the certolizumab (CZP) RAPID1 and RAPID2 trials to assess the risk of serious infectious events (SIEs), and shown that steroids combined with an age-adjusted comorbidity index (AACI) yields a 2-3 fold predictable risk for SIE.