This is somewhat of a PSA for anyone else whose child gets put on Dapsone. This is something that I didn't even know about until today.

Dylan (7, dx 12-1-08) was started on Dapsone last week since the Septra suppresses his counts causing really long delays in starting chemo and the attempt to give him Pentamidine was a total disaster. He started last Monday and then by last Friday I would've sworn he needed a blood transfusion because he was pale, weak, headache and even had a dizzy spell at physical therapy. So we went upstairs to clinic to check counts. Everything looked pretty good. Counts were down some but well above transfusion levels. Went home thinking what a paranoid nut I have become for thinking he needed a transfusion when everything was actually fine. Then today, he woke up at 9 this morning to throw up and went right back to sleep, didn't wake back up until 1:30 this afternoon. He was complaining of headache, nausea, stomach and back pain. I'm rationalizing all these symptoms since he got another dose of the IV methotrexate and vincristine on Monday (Augmented Interim Maintenance II) and these drugs made him feel pretty bad the last time he had them. Also, I was seriously doubting my mommy radar since I was so wrong last Friday. So anyway, he is trying to do his stretches and he can only do about 30 seconds of activity and then has to stop for a rest. Now I know for sure there is something weird going on with him. We stop the physical therapy and head back upstairs to clinic again. I have to carry him because he doesn't have the energy to walk. By the time I explain what is going on, he is looking pretty sick. His vitals showed him to be running a low grade fever, tachycardic and his SpO2 was low. His lips and under his eyes were kind of a greenish-purple color and three of his docs come rushing in to check him out. Yep, as it turns out, my mommy radar was working just fine all along. Now I wish I would have been a little pushier about them checking him out more thoroughly last week.

Turns out that the Dapsone can cause methemoglobinemia. A "rare" disorder of the red blood cells where these methoglobins that can't bind or carry oxygen become elevated (normal is less than 1%). Signs and symptoms typically include shortness of breath, cyanosis, mental status changes (noticed this yesterday trying to do schoolwork with him but didn't think too much of it at the time), headache, fatigue, exercise intolerance, dizziness, loss of consciousness, dysrhythmias, seizures, coma and death (at levels over 70% in healthy people but people with underlying conditions can get the more severe symptoms at levels of just 7 to 8%!!!). Dylan's nurse said she's only seen it a few times before. Luckily we caught Dylan's before it became too critical and he was just treated with oxygen and flushed with a large bolus of fluids to help clear the dapsone from his system. Symptoms should start to improve sometime tommorrow hopefully. He is just under observation for now. Obviously, now he will no longer be able to take the Dapsone either. It looks like after all this effort to get him on something that won't suppress counts, he is going to have to go right back on the Septra again. Ughh... Oh how I hate thee, leukemia!

www.caringbridge.org/visit/dylankinsey