MEDICATIONS - Medicine for Mountaineering and Other Wilderness Activities - page 520

Azithromycin (Zithromax®) is generally effective against pneumococci, streptococci,
and mycoplasma. It is not effective for most staphylococcal infections. This drug is now
available generically andisusedprimarilytotreatthemorecommoncausesofpneumonia.
Precautions: Very few adverse reactions to azithromycin occur, and those that do ap-
pear are mild.
Clindamycin
Clindamycin is another antibiotic with antibacterial effects similar to penicillin and is a
suitable substitute for individuals allergic to penicillin. In addition, clindamycin is effect-
ive against staphylococci, particularly methicillin-sensitive Staphylococcus aureus , and a
number of anaerobic organisms, particularly Bacteroides fragilis , one of the most common
of the anaerobic organisms that cause peritonitis.
Precautions: A significant number of the individuals being treated with clindamycin
develop diarrhea. Usually the diarrhea is mild, and treatment can be continued. However,
rare individuals develop a life-threatening colitis from overgrowth of toxin-producing bac-
teria, Clostridium difficile , in the colon. Such infections can develop with therapy by other
antibiotics( Chapter19:GastrointestinalDisorders ).Copiousfluidsandelectrolytesarelost
and large amounts of blood and mucus appear in the stools. Clindamycin must be stopped
at once if this type of diarrhea appears, the lost fluids must be restored—intravenously if
necessary—and metronidazole should be administered.
The Tetracyclines
The tetracyclines—tetracycline and doxycycline (Vibramycin®)—are effective treat-
ment for infections produced by a broad spectrum of organisms that includes rickettsia and
some viruslike organisms as well as a large number of gram-positive and gram-negative
bacteria. However, the tetracyclines are bacteriostatic drugs, and a number of more effect-
iveagentshavereplacedthemforthetreatment ofmanyinfections.Currentlythedisorders
forwhichtetracyclines aretheantibiotic ofchoice aretheearly stage ofLymedisease, ehr-
lichiosis (anaplasmosis), certain mycoplasmal and rickettsial infections, and cholera.
Precautions: Tetracycline therapy may cause mild diarrhea due to the suppression of
normalintestinalbacteria.Thediarrheaisrarelysevereandusuallyendswhenthedrughas
been stopped.
Nausea and vomiting sometimes occur in persons receiving tetracyclines.
All tetracyclines increase sensitivity to ultraviolet light and predispose individuals re-
ceiving them to severe sunburn.
Tetracyclines can permanently stain the dental enamel in young children. It should not
be administered to children and pregnant women when other agents are available.