My 87 yo mother has the following history. We have the following questions and would really appreciate your help.
09/2012 dx with cancer left lung near hilar
11/2012 completed SBRT treatment 60Gy
06/14/2013 admitted to hospital with presumed pneumonia on xray- symptoms were - fever,some coughing, extreme SOB w low O2 level upon exertion, CT done to rule out pulmonary embolism, showed large infiltrate over area radiated. Also taking nitrofurantoin (macrobid) for uti before hospital admittance.
Treated with vancomycin 2 days, followed by another antibiotic but O2 continued to decrease, bronchial lavage performed with no findings or specific bacteria,increased oxygen to 6LPM, finally put on 60mg daily prednisone followed by marked improvement same day. Pulmonary doctor leaning toward pneumonitis diagnosis. Continued prednisone with tapering.Prednisone tapered from 7.5mg to 5mg/day around 9/1.
09/6/2013 same symptoms again presented (fever, slight cough,extreme SOB,low oxygen needs 24/7) Again put on macrobid for another uti end of August.
Could you please address the following questions-
1. A followup CT is scheduled for next week w/o contrast- can this show pneumonitis as well as w contrast?
2. Will a MRI show pneumonitis?
3. My research shows that macrobid(nitrofurantoin) can also cause pneumonitis, although not common. My mother has been prescribed this for many years for recurring UTI's so I am concerned it may be the cause. Would the treatment be the same and/or since infiltrate is over the area radiated is it reasonable to assume the pneumonitis is from the radiation and not the macrobid?
Thanks so much for your help!
Reply # - September 9, 2013, 07:18 PM
Reply To: radiation / drug-induced pneumonitis questions
Yes, a noncontrast CT can show pneumonitis well.
An MRI could probably show pneumonitis, but I've never done an MRI for that. A chest CT would be far more common as the method for assessing for pneumonitis.
I think it's exceptionally unlikely that macrobid would cause a pneumonitis in the area of the radiation. Many medications have been reported as being rarely associated with pneumonitis (and just about every other complication), but they should cause a more diffuse pneumonitis process, rather than a focal one where the radiation was administered.
-Dr. West
Reply # - September 10, 2013, 03:46 PM
Reply To: radiation / drug-induced pneumonitis questions
Thanks for your quick response Dr. West. Would you mind addressing a few more concerns, or do I need to open a new thread??
My mothers doctor bumped up the prednisone from 5mg to 20mg/day for 2 days, followed by 10mg/day for 2 days, then stopping completely. She began the 20mg yesterday but so far it has not helped her oxygen level unlike her first regimen of prednisone several months ago (although it was 60mg).
1.How long would you think it would take for the prednisone to help her oxygen level?
2. If her oxygen level continues to stay low what would you test for next?
Her CT scan is 10 days out and doctors office said no need to push up, but with this being so sudden it is concerning.
3. Could this be fibrosis or would you expect fibrosis to set in more slowly?
4. Any idea why her prednisone dosage would have to be tapered from 20mg to 5mg over a month span, but now that it is bumped back up to 20mg it will be tapered to 0 in 4 days? Is this normal second time around?
Any insight would be greatly appreciated! I was so encouraged by her rapid recovery- the docs even had her in physical rehab riding a bike on the prednisone. Now she is so sick and can hardly walk from hip pain.
Reply # - September 10, 2013, 08:33 PM
Reply To: radiation / drug-induced pneumonitis questions
I'm sorry, but I really don't have enough of an expertise in this, particularly in someone who isn't my patient, to delve into these kinds of details. I work with a pulmonologist to assist me in these matters.
Pulmonary fibrosis generally occurs over a period of months to years, not weeks.
Beyond that, I think you'd to speak to the doctor about the decision on the timeline of the new taper.
-Dr. West