Bacitracin Bacitracin is a<unk>  derived from a bacterium, Bacillus subtilis, and acts against bacteria through the inhibition of cell wall synthesis. It does this by inhibiting the removal of phosphate from lipid compounds, thus deactivating its function to transport peptidoglycan; the main component of bacterial cell membranes, to the microbial cell wall. Bacitracin has been used in clinical practice mainly as a topical medication due to its toxicity being too high for parental use, however evidence successful treatment in clinical trials is limited. Surgeons are able to use Bacitracin in skin grafting procedures, due to its non-toxic quality. Pseudomembranous colitis; the inflammation of the large intestine was successfully treated with Bacitracin as an oral treatment, in the case of the two patients suffering relapses of the infection and allergic reactions, respectively, to the common antibiotic treatment with vancomycin. In 1980, the use of oral bacitracin successfully treated four cases of colitis and diarrhea associated with antibiotic use, caused by the bacteria Clostridium difficile. However, two of the patients suffered relapses, whilst the other 2 cases experience early stages of relapse. One relapsed patient was subsequently treated successfully with vancomycin. Bacitracin was also trialled in bullous impetigo, an acute blistering infection, however produced ineffective results with no significant difference in success rate in comparison to the placebo trials. Patients who continued to have new development of lesions further required alternative drug therapy, in a study undertaken by Ruby and Nelson, 1973. As a result, further studies of Bacitracin treatment in Impetigo, and to compare vancomycin and bacitracin are required. Polymyxins Polymyxins are a class of<unk> s that act on bacteria via disrupting the transport mechanism of the cell wall. The application of polymyxin to treat serious cases of infections caused by Pseudomonas aeruginosa strains is rare. It is used when the patient has developed resistance to less toxic and more commonly used antibiotics, in this case are aminoglycosides and antipseudomonal penicillins. Polymyxins are also distributed as an inhaled medication to treat minor respiratory tract infections due to Pseudomonas, such as cystic fibrosis. More commonly, polymyxin is distributed as a topical medication for patients with superficial infections, such as infected varicose ulcers. Polymyxin E, also referred to as colistin, is one of the few<unk> s able to be systematically absorbed via oral consumption. It is used to treat leukaemia patients who suffer low levels of white blood cells. With use, non-toxic side effects of casts and azotaemia in the urine are observed in most patients. Bleomycin Bleomycin is a<unk>  derived from a fungus, Streptomyces verticillus. Its mechanism of action involves bleomycin binding to guanine bases in deoxyribonucleic acid (DNA) with the oxidation of ferrous iron to ferric iron. The oxidation donates an electron that the oxygen accepts to form a reactive species of oxygen. The reactive oxygen entities attack DNA bases which store information, and thus inhibits DNA synthesis. Bleomycin also acts via interfering with cell wall synthesis in the target bacteria, however the exact mechanism of action is undetermined. Bleomycin's medical application is as an anti-tumour drug mainly in germinative tumours and Hodgkin's lymphoma, however its use is limited by pulmonary toxicity. In a study of combining bleomycin and other medicinal agents in bladder cancer cells, results showed bleomycin induced DNA damage to all the cell lines tested. Thus, bleomycin as a combination therapy may be an option to treat tumours. Efficacy rates of bleomycin in conjunction with cisplatin and etoposide in testicular cancer is approximately 90% successful. Bleomycin also does not induce myelosuppression with decreased bone marrow activity, or immunosuppression; suppressing the immune responses in patients unlike alternative cytotoxic drugs. However, further trials are required as pulmonary toxicity occurs in approximately 10% of patients, with around 1% cases of death due to pulmonary fibrosis.
Polypeptide antibiotic
Quinolone antibiotic
Protease inhibitor 
Lipase inhibitors
Antiviral drug
Beta-lactam antibiotics
Antimetabolite
Sulfonamide 