Are there any side effects for using tetracycline over the long term? 
I would define long term as 6 months - 2 years.

I took 500mg of tetracycline daily for 2 years while I was in high school for
treatment of acne.  Now almost 10 years later, I am once
again taking tetracycline (500mg daily) for treatment of acne.  I have
been taking it for 6 months and may have to continue for another 6
months or so.  Should I be concerened about any side effects?  Can my
body become resistant to antibiotics for taking tetracycline for so
long?

jacques77...

Thank you for your question.  I do want to emphasize that Answers
provided on Google Answers are general information, and are not
intended to substitute for informed professional medical advice.  You
should address your concerns regarding use and side effects of any
medication to the doctor that prescribed them to you.

Oral tetracycline has long been used in the treatment of acne, and
remains one of the most widely used. A typical tetracycline regimen
for treating moderate to severe acne is a starting dose of 500 to 1000
milligrams a day. Long-term, low-dose tetracycline therapy may be
continued for many months to maintain suppression of acne. Higher
doses may be prescribed for very severe acne, with regular monitoring
for systemic side effects. One concern, however, is if you are female
and are planning on getting pregnant, you should contact your doctor
as tetracycline may cause permanent teeth staining or skeletal defects
in a fetus.  Also, I am sure you are aware of the photosensitivity
issues that can be caused by the use of tetracycline.


In reviewing several pages of information on tetracycline, I found no
evidence of any long term effects.  There were several cases of people
taking tetracyline for years (as high as 7 in one case) with no long
term effects. The biggest concern was some gastrointestinal issues
that are a common side effect of the medication. That being said, I
wish to emphasize again that you should discuss your concerns with
your physician and/or dermatologist.

Thanks again for your question.  If you need any additional
clarification, please let me know prior to rating my answer.

Regards,

-THV

Search Strategy:
long term use of tetracycline
side effects tetracycline

References:

Rate-It-All
http://www.rateitall.com/item.asp?i=4126D70D-A29D-44DA-AD3F-17BD84550DCD

Yarchive
http://yarchive.net/med/tetracycline.html

Medizine
http://www.cix.co.uk/~cyberville/medizine/tetracyc.htm

AcneNet
http://www.skincarephysicians.com/acnenet/jun01.html

Thanks for the precise answer to my question.

Hi Jacques,
I just wanted to add to the excellent answer provided.

From UptoDate:
"Oral antibiotics are prescribed for daily use over four to six
months, with subsequent tapering and discontinuation as acne improves.
Antibiotics may be continued at the lowest effective dose indefinitely
in those with persistent acne, although this practice can lead to
antibiotic resistance . . . Antibiotic resistance has become an
increasing problem in patients with acne. One report suggests that the
incidence of P. acnes antibiotic resistance has increased from 20
percent in 1978 to 62 percent in 1996 (2). Factors that contribute to
this increasing incidence include the widespread use of oral
antibiotics and the practice of rotating antibiotics." (1)

1) Wirth, F.  Approach to acne vulgaris.  UptoDate, 2002.
2) Cooper, AJ. Systematic review of Propionibacterium acnes resistance
to systemic antibiotics. Med J Aust 1998; 169:259.

Thanks,
Kevin, M.D.

tar_heel_v: thanks for the precise answer.
kevinmd: thanks for your input as well.

I'll go ahead and rate the answer since my primary question about side
effects was answered.

On the issue of building a resistance to an antibiotic such as
tetracycline: if someone were to become resistant to tetracycline,
would that mean resistance specifically to tetracycline, to
antibiotics similar to tetracycline, or to all antibiotics?  And, how
would you know if you were resistant?

Or... do I have it backwards?  Your *body* doesn't become resistant to
the antibiotic but instead the *germ* (acne) becomes resistant to the
antibiotic.

That's right, Jaques.  The bacteria that are *not* killed by the
antibiotic are the resistant ones.  The scary thing about antibiotic
resistance is that the resistance may be passed on to other bacteria. 
It may be worthwhile discussing this with your doctor, and seeing if
any other treatments are available, without the need for such
long-term usage.

Araminty-ga
Google Answers Researcher.