How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask AnnlynnRN Your Own Question
AnnlynnRN, Nurse (RN)
Category: Health
Satisfied Customers: 583
Experience:  RN - 16 years in ICU & Critical Care (Cardiac, Neurology, Trauma, & Medical/Surgical ICU.)
Type Your Health Question Here...
AnnlynnRN is online now
A new question is answered every 9 seconds

chronic lung disease treatment

This answer was rated:

Whould a doctor prescribe smz/tmp as a preventative med 3x's a week for chronic lung disease associated only with pneumocystis type? Or are there other types of chronic lung disease for which this med would be prescribed for on a preventative dosage?


Usually for adults, the dosing is 800 mg. of sulfamethoxazole and 160 mg. of trimethoprim (SMZ/TMP) once a day for prevention of PCP (Pneumocystis carinii pneumonia.)

In answer to your first question...yes, a doctor would be acting appropriately in prescribing smz/tmp as a preventative for PCP three times a week.  It is with infants and children that the preventative dose for PCP is based on body size (which is determined by the doctor.)  There are several dosing regimens.  One regimen is what you mentioned in your post, and consists of 375 mg. of sulfamethoxazole and 75 mg. of trimethoprim per square meter of body surface twice a day, three times a week for three consecutive days in a row.

SMZ/TMP has other uses such as for urinary infections, middle ear infections, prostatitis, pneumonitis, and bronchitis.

Pneumonitis and bronchitis are other types of lung infections.  Both can be chronic, however it is not likely to be prescribed SMZ/TMP for preventative use for these infections as the drug can be toxic to the kidneys and risks of blood disorders.

Please write back if you need further clarification.   


AnnlynnRN, Nurse (RN)
Category: Health
Satisfied Customers: 583
Experience: RN - 16 years in ICU & Critical Care (Cardiac, Neurology, Trauma, & Medical/Surgical ICU.)
AnnlynnRN and 3 other Health Specialists are ready to help you
Customer: replied 11 years ago.
Reply to AnnlynnRN's Post: My father which is on social security disability for this reason is living with me, but is very vague on his health condition. I have been researching his treatment with this medication and his doctor has prescribed this Rx for him to take every Mon, Wed, and Friday and has given him 99 refills for the entire year. I am afraid that he is terminally ill with possibly HIV after my research. He has told me that he has been told that he has chronic lung disease. To my understanding, this medication on a preventative regimen is only likely to treat a pneumocystis carinii pneumonia which is related only to HIV. Is this correct or is this type of pneumonia associated with other lung problems? I hope you can help and I understand that this is not a definite diagnosis without all facts and only a probable cause. I am concerned and worried about him. Please help.


I am so sorry for what you must be going through.  I wish I could
give you better news, but you seem to have done your homework and you
are correct.

PCP (pneumocystis carinii pneumonia) is a common organism that may
reside harmlessly in normal, "healthy" lungs and usually only causes
disease when the body's immune defenses are weakened due to cancer,
treatment of cancer, or AIDS.

More than 80% of AIDS patients who DO NOT receive prophylactic
(preventative) treatment develop PCP at some time.  Often, it is
the first indication that a person with HIV has developed into
AIDS.  On a more positive note, your father is taking the
appropriate preventative medication, smz/tmp (sulfamethoxazole -
trimethoprim) to prevent PCP. 

Although this medication can also be used for urinary tract infections, ear infections, prostatitis, and bronchitis, etc,  the dosing regimen your father is taking (three times a week) is highly indicitive of the preventative treatment for PCP.

I am so sorry.  I can hear the desperation for a glimmer of hope
in your post, and I wish I could give you that.  Michelle, your
father is most likely protecting you by not being up front with his
illness.  Talk to him.  Tell him you understand what is going
on, and encourage him to share with you the truth about his
illness.  It must be very scary and lonely for him to deal with
all of this by himself.  And you are obviously scared, too. 

I will do some searching for support groups for patients and families
affected by HIV and AIDS and send them to you in my next post. 
You need to have support for yourself so that you can help support your
father.  My prayers are with you.  Please feel free to write
back any time for questions, answers, a shoulder to cry on, or an ear
to listen.  I'll write back soon when I find some info for
you.      God
Bless,       AnnlynnRN



I did not have much luck finding support groups in your area, however I
did find some phone numbers for you that can point you in the right
direction and offer resources available to both you and your father:

Indiana AIDS Hotline: 1-(800)-848-2437

National AIDS Hotline: 1-(800) 342-AIDS

I hope you take advantage of the above hotline
numbers.  They are experts who can offer you a wealth of
information, provide you with support groups in your area, and teach
you ways to cope with the difficult road that lies ahead.  Perhaps
you can call the support hotlines above before speaking with your
father so you can be better prepared.  Whatever you decide, you
will be in all of our thoughts and prayers.  Please write back and
let us know how you are doing.  God Bless.    

Customer: replied 11 years ago.
Thank you so much for all of your help and I already expected this answer, but I think I still need time now to process the news. Thanks again and will keep you posted.

JustAnswer in the News:

Ask-a-doc Web sites: If you've got a quick question, you can try to get an answer from sites that say they have various specialists on hand to give quick answers... seen a spike since October in legal questions from readers about layoffs, unemployment and severance.
Web sites like
...leave nothing to chance.
Traffic on JustAnswer rose 14 percent...and had nearly 400,000 page views in 30 days...inquiries related to stress, high blood pressure, drinking and heart pain jumped 33 percent.
Tory Johnson, GMA Workplace Contributor, discusses work-from-home jobs, such as JustAnswer in which verified Experts answer people’s questions.
I will tell you that...the things you have to go through to be an Expert are quite rigorous.

What Customers are Saying:

  • I can go as far as to say it could have resulted in saving my sons life and our entire family now knows what bipolar is and how to assist and understand my most wonderful son, brother and friend to all who loves him dearly. Thank you very much Corrie Moll Pretoria, South Africa
< Previous | Next >
  • I can go as far as to say it could have resulted in saving my sons life and our entire family now knows what bipolar is and how to assist and understand my most wonderful son, brother and friend to all who loves him dearly. Thank you very much Corrie Moll Pretoria, South Africa
  • I thank-you so much! It really helped to have this information and confirmation. We will watch her carefully and get her in for the examination and US right away if things do not improve. God bless you as well! Claudia Albuquerque, NM
  • Outstanding response time less than 6 minutes. Answered the question professionally and with a great deal of compassion. Kevin Beaverton, OR
  • Suggested diagnosis was what I hoped and will take this info to my doctor's appointment next week.
    I feel better already! Thank you.
    Elanor Tracy, CA
  • Thank you to the Physician who answered my question today. The answer was far more informative than what I got from the Physicians I saw in person for my problem. Julie Lockesburg, AR
  • You have been more help than you know. I seriously don't know what my sisters situation would be today if you had not gone above and beyond just answering my questions. John and Stefanie Tucson, AZ
  • I have been dealing with an extremely serious health crisis for over three years, and one your physicians asked me more questions, gave me more answers and encouragement than a dozen different doctors who have been treating me!! Janet V Phoenix, AZ

Meet The Experts:

  • Family Physician

    Family Physician

    Doctor (MD)

    Satisfied Customers:

    Emergency Medicine and Family Practice for over 26 years
< Last | Next >
  • Family Physician's Avatar

    Family Physician

    Doctor (MD)

    Satisfied Customers:

    Emergency Medicine and Family Practice for over 26 years
  • Nurse Milli, RN's Avatar

    Nurse Milli, RN

    Nurse (RN)

    Satisfied Customers:

    20 years experience in many areas of Nursing. Both Hospital and Private Practice experience.
  • Dr. Ketch's Avatar

    Dr. Ketch


    Satisfied Customers:

    Medical Degree, Former Assistant Professor at School of Medicine at Yale University
  • Dr. Arun Phophalia's Avatar

    Dr. Arun Phophalia

    Doctor (MD)

    Satisfied Customers:

    MBBS, MS (General Surgery), Fellowship in Sports Medicine
  • A. Schuyler, NP's Avatar

    A. Schuyler, NP

    Nurse Practitioner

    Satisfied Customers:

    Board Certified NP, MS, RN. Private practice & hospitalist
  • Dr. Mark's Avatar

    Dr. Mark

    Doctor (MD)

    Satisfied Customers:

    U.S. Physician/Surgeon in Neurosurgery
  • Dr. Gupta's Avatar

    Dr. Gupta

    Doctor (MD)

    Satisfied Customers:

    Vastly experienced MD Physician with 19 years of experience.