It Feels Like I Am Swallowing Raw Oats in Sclero Forums (MAIN) Posted November 26, 2006 Hi Heddy, I'm sorry to hear you have a severe sore throat. As it happens, people on methotrexate are supposed to contact their doctor right away if they have any signs of infection (such as sore throat). Methotrexate can interact with antibiotics. Also it is most beneficial to have a throat culture before taking any type of antibiotic, since even a single dose can cause a false negative for a strep test. Of course, you certainly can't take back what has already occurred. But it's not too late to call your doctor and sort things out. Usually methotrexate is very well-tolerated, but it does require working closely with your doctor on it. For more information, see Methotrexate at Drugs.com. I hope you get back up to snuff fairly soon.