The purpose of an antihistamine is to work against the effects of histamine, a chemical substance found in nearly all body tissues. Histamine is released in response to injury or invasion by foreign substances such as pollens (see allergy). It is also the irritating agent in certain insect venoms.
Metronidazole for a Strep B Infection. Group B Strep is a strain of the streptococcus bacteria that can cause serious illness and is potentially life threatening, especially in newborns, pregnant women, elderly patients, or anyone with any already compromised immune system.
Antibiotics are commonly used to treat strep throat because they: 1  Kill the bacteria and shorten the time the patient is contagious. The patient usually is no longer contagious 24 to 48 hours after starting antibiotics.  Prevent rare complications.