Examples
|
| Doryx, Vibramycin | doxycycline | |
How It Works
Tetracyclines make it difficult for bacteria to reproduce.
Why It Is Used
Doctors use tetracyclines to treat lower
respiratory tract 
infections in otherwise healthy
people younger than 65. These medicines are an alternative antibiotic when you
cannot take one of the macrolide antibiotics.
Doxycycline is not effective against some types of Streptococcus pneumoniae, the bacteria that cause most
identified cases of pneumonia. This is because the bacteria are
resistant to it.
How Well It Works
In general, all antibiotics used have a high cure rate for
pneumonia. For people in the hospital, cure rates are 73% to 96%. Outside of
the hospital, cure rates are generally above 80%.1
Tetracyclines are effective against some types of Mycoplasma pneumoniae, Streptococcus pneumoniae, Chlamydial pneumoniae, and
Haemophilus influenzae. But bacteria that are resistant
to tetracycline are common.
You most likely will see some improvement in symptoms within 2 to
3 days after beginning treatment. Unless you get worse during that time, your
treatment will not change for at least 3 days. The number of days you continue
to take antibiotics depends on your illness and the type of antibiotic.
Side Effects
The most common side effects of tetracyclines include:
- Increased sensitivity to sun (sunburn
easily).
- Stomach upset, nausea,
vomiting.
- Dizziness.
- Sore mouth.
Doctors do not use tetracyclines for children younger than age 8
because the medicine can discolor a child's teeth.
See Drug Reference for a full list of side effects. (Drug Reference
is not available in all systems.)
What To Think About
Tetracyclines are less expensive than some other antibiotics, but
certain strains of bacteria may be resistant to them.
You should not take tetracyclines with dairy products (such as milk
or cheese) because this can affect the way your body absorbs the
medicines.
Complete the new medication information form (PDF) 
(What is a PDF document?)
to help you understand this medication.
References
Citations
Loeb M (2006). Community acquired pneumonia, search
date April 2005. Online version of Clinical Evidence
(15): 1-10.
Credits
| Author | Ralph Poore |
| Editor | Susan Van Houten, RN, BSN, MBA |
| Associate Editor | Pat Truman, MATC |
| Primary Medical Reviewer | Caroline S. Rhoads, MD - Internal Medicine |
| Specialist Medical Reviewer | R. Steven Tharratt, MD, MPVM, FACP, FCCP - Pulmonology, Critical Care, Medical Toxicology |
| Last Updated | April 2, 2007 |
