Page 829 - Basic _ Clinical Pharmacology ( PDFDrive )

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C
P
H
E
T
R
A
Tetracyclines,

Macrolides, Clindamycin,

Chloramphenicol,

Streptogramins, &

Oxazolidinones

Camille E. Beauduy, PharmD, &
Lisa G. Winston, MD

C ASE STUD Y

A 22-year-old woman presents to her college medical clinic motion tenderness is present. A first-catch urine specimen is
complaining of a 2-week history of vaginal discharge. She obtained for chlamydia and gonorrhea nucleic acid amplifi-
denies any fever or abdominal pain but does report vaginal cation testing. A urine pregnancy test is also ordered as the
bleeding after sexual intercourse. When questioned about patient reports she “missed her last period.” Pending these
her sexual activity, she reports having vaginal intercourse, results, the decision is made to treat her presumptively for
at times unprotected, with two men in the last 6 months. A chlamydial cervicitis. What are two potential treatment
pelvic examination is performed and is positive for muco- options for her possible chlamydial infection? How does her
purulent discharge from the endocervical canal. No cervical potential pregnancy affect the treatment decision?

The drugs described in this chapter inhibit bacterial protein OH O OH O
synthesis by binding to and interfering with ribosomes. Most are 11 OH 1 O
bacteriostatic, but a few are bactericidal against certain organ- 9 10 12 2 C NH
isms. Tetracycline and macrolide resistance is common. Except 8 7 3 OH 2
for tigecycline and the streptogramins, these antibiotics may be R 6 5 R H 4
3 2
administered orally. R 7 6 OH H 5 N(CH )
Renal
Clearance
R 7 R 6 R 5 (mL/min)
■ TETRACYCLINES Chlortetracycline C I CH 3 3 H 35
90
OH
CH
H
Oxytetracycline
Tetracycline H CH3 H 65
Demeclocycline C I H H 35
All of the tetracyclines have the basic structure shown at right: Methacycline H CH * OH 31
2
Doxycycline H CH * OH 16
3
Minocycline N(CH ) H H 10
3 2
*There is no OH at position 6 on methacycline and doxycycline.
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