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.
Yes and No: Not for strep throat. It could work some sinus infections. But, it depends on what bacteria caused the infection. Amoxil (amoxicillin) or one of the penicillins would be for strep and would help a lot of sinus infections.