Antimicrobial Therapy



1.        Penicillins


Penicillin used as the drug of choice for S. pyognes, S. Pneumoniae, N. Meningitidis, N. gonorrhoea, B. anthracis, C. diptheriae, T. pallidum, P. multicoda, and certain anaerobes.


Methicillin group (Penicillinase-resistant) used for S. Aureus


Ampicllin/amoxycillin for haemophillus and other gram-negative organisms


2.        Cephalosporins


1st generation e.g. cephalexin very active against gram-positive cocci


2nd generation e.g. cefuroxime additional activity against H. influenza, M. catarrhalis, N. menigitidis and Gonorrhoea.


3rd generation active against gram-negative bacilli. Some e.g. ceftazadime are active against pseudomonads as well.


3.        Imipenam


(another B lactam antibiotic) active against a wide range of bacteria


Its is most useful against ESBL organisms


4.        Aminoglycosides


Streptomycin, gentamycin, kanamycin, amikacin

Used against gram-negative bacilli including pseudomonads


5. Rifamycins


Rifampin is used against MTB and also as prophylaxis against N. menigiditis


6. Metronidazole


Used against anaerobes and certain parasitic infections


7.        Erthromycin and other macrolides

Used mainly as a second line drug for penicillin. Used first line for legionella and sometimes for chlamydial and mycoplasmal infections


Clindamycin is mainly used in the treatment of anaerobic infections.


8.        Vancomycin


For MRSA infections


9.        Tetracyclines


Tetracycline and doxyclyine are used for a wide variety of bacterial, chlamydial, and rickettsial infections


10.    Sulphonamides


Sulphonamides are often used in conjunction with trimethroprim. It is used for treating UTI and respiratory infections


11.    Quinolones


Ciprofloxacin and Ofloxacin are active against a large umber of gram-negative bacilli including P. aeruginosa.