A little worried about my treatment

[Jeff vinc]

Hi,

I am a little unsure about my treatment.
I started methotrexate 15mg once a week yesterday and they also want me to use septra DS(sulfatrim/trimeth DS) 160mg to take every 2days. After a few research i found that they recommend to avoid to take these 2 medications because Sulfonamides (septra) may decrease the renal clearance of methotrexate. Serum levels of free methotrexate and the risk of bone marrow suppression may be increased. Sulfonamides may also displace methotrexate from plasma protein binding sites, which may further increase serum methotrexate levels and the risk of toxicity. Methotrexate toxicity has also been reported in patients receiving low weekly doses.
I want to wait until monday to talk to my rheuma before i start the septra. I am starting blood works every months to keep tracking my WBC's because of that mix of meds.
I just want to know if anybody used these meds together.