Antibiotic, Antifungal, Antiviral Drugs

The drug also is active in vitro against Arcanobacterium haemolyticum (formerly Corynebacterium haemolyticum). Clindamycin is active against some anaerobic and microaerophilic gram-negative and gram-positive organisms including Actinomyces, Bacteroides, Eubacterium, Fusobacterium, Propionibacterium, microaerophilic streptococci, Peptococcus, Peptostreptococcus, and Veillonella. Clindamycin is active in vitro against Prevotella and Porphyromonas (both formerly classified as Bacteroides); Mobiluncus (motile, anaerobic, curved rods) also are inhibited in vitro by the drug. Clostridium perfringens, C. tetani, Corynebacterium diphtheriae, and Mycoplasma are also inhibited by clindamycin.

Adverse GI effects frequently occur with oral, IM, or IV clindamycin and may be severe enough to necessitate discontinuance of the drug. Adverse GI effects of clindamycin include nausea, vomiting, diarrhea, abdominal pain, and tenesmus.

Clindamycin hydrochloride and clindamycin palmitate hydrochloride are administered orally. Clindamycin phosphate is administered by IM injection or by intermittent or continuous IV infusion. Clindamycin hydrochloride capsules and clindamycin palmitate hydrochloride oral solution can be administered without regard to food. To avoid the possibility of esophageal irritation, clindamycin hydrochloride capsules should be administered orally with a full glass of water.

Clindamycin generally is used for the treatment of serious infections caused by susceptible gram-positive bacteria and for the treatment of serious infections caused by susceptible anaerobic bacteria. Because the risk of severe, potentially fatal Clostridium difficile-associated diarrhea and colitis may be higher with clindamycin than with certain other anti-infectives, use of the drug should be limited to serious infections for which less toxic and/or more effective anti-infectives are not readily available. However, it should be noted that C. difficile diarrhea and colitis has been associated with the use of nearly all anti-infectives, being reported most frequently with clindamycin, cephalosporins, and ampicillin; second and third generation cephalosporins play an increasingly important role.

Limited information is available on the acute toxicity of vancomycin. The IV LD50 of the drug in rats or mice is 319 or 400 mg/kg, respectively. Treatment of vancomycin overdosage is mainly supportive with maintenance of glomerular filtration.

Ototoxicity and nephrotoxicity are the most serious adverse effects of parenteral vancomycin therapy. To date, these adverse effects have not been reported in patients receiving vancomycin orally. The incidences of ototoxicity and nephrotoxicity have not been well established, but clinical experience to date suggests that these adverse effects occur relatively infrequently.

Vancomycin hydrochloride is administered by slow IV infusion for the treatment of systemic infections. Vancomycin hydrochloride is given orally as capsules or an oral solution for the treatment of enterocolitis caused by Staphylococcus aureus (including methicillin-resistant strains) or for antibiotic-associated pseudomembranous colitis caused by Clostridium difficile; if necessary, the parenteral form of vancomycin HCL also may be administered orally for the treatment of these infections.

IV vancomycin hydrochloride is used in the treatment of potentially life-threatening infections caused by susceptible organisms which cannot be treated with other effective, less toxic anti-infective agents. Vancomycin is used principally for the treatment of severe infections caused by gram-positive bacteria in patients who cannot receive or who have failed to respond to penicillins and cephalosporins or for the treatment of gram-positive bacterial infections that are resistant to b-lactams and other anti-infectives. Prevention of the emergence of drug resistance, its dissemination among pathogens, and the spread of such pathogens has become an increasingly important public health problem. Medical, pharmacy, and other staff and individuals responsible for drug-use policy and formulary decisions should review and restrict the use of certain anti-infectives, including vancomycin, and ensure that their use is appropriate.

Daptomycin is used for the treatment of complicated skin and skin structure infections caused by susceptible gram-positive bacteria. The drug should not be used in the treatment of pneumonia. To reduce the development of drug-resistant bacteria and maintain daptomycin efficacy, the drug should only be used to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria.

IM bacitracin has been used in infants with pneumonia and empyema caused by staphylococci that are susceptible to the drug; however, use of bacitracin has, in most cases, been replaced by penicillinase-resistant penicillins or cephalosporins for infections caused by penicillinase-producing staphylococci and by vancomycin for resistant strains. Penicillin is the drug of choice in infections caused by susceptible strains of nonpenicillinase-producing staphylococci. If bacitracin is used, the patient should be closely observed, and adequate laboratory facilities should be available. Diarrhea and Colitis Bacitracin has been used orally in a limited number of patients for the treatment of Clostridium difficile-associated diarrhea and colitis (also known as antibiotic-associated diarrhea and colitis), including pseudomembranous colitis.