Antibiotics (Properties, Administration, Interactions) - Posokhova K.A., Viktorov O.P. 2005

Glycopeptide, lipopeptide, and polypeptide antibiotics
Polypeptide antibiotics

Polypeptide Antibiotics include colistin, polymyxin B (M), bacitracin, and gramicidin.

They are effective against Gram-negative Bacteria, particularly Pseudomonas aeruginosa.

Polymyxin B sulfate is used to treat severe hospital-acquired infections, such as Sepsis, meningitis, Pneumonia, and Urinary Tract Infections caused by P. aeruginosa or other Gram-negative microorganisms (e.g., Escherichia coli, Enterobacter). The drug is prescribed only when the pathogen is resistant to less toxic medications. Occasionally, it is used for gastrointestinal infections caused by susceptible microorganisms (such as Salmonella and Shigella species).

Polymyxin B sulfate is administered intramuscularly at a dose of 0.5–0.7 mg/kg of body weight 3–4 times daily, not exceeding 0.2 g per day. Intravenous infusion of the drug is performed twice a day (at 1 mg/kg of body weight), up to a maximum of 150 mg per day. For oral administration, 100 mg is prescribed every 6 hours.

Adverse effects of polymyxin B sulfate. Nephrotoxic effects manifest as albuminuria, cylindruria, azotemia, proteinuria, and renal tubular necrosis. During prolonged Treatment, renal function must be monitored every 2 days. Central Nervous system effects may include dizziness, somnolence, impaired consciousness, paresthesia, neuromuscular blockade, including paralysis of the Respiratory Muscles leading to apnea. Polymyxin B may cause visual disturbances, dyspeptic symptoms (nausea, anorexia), and allergic reactions (Skin rashes, pruritus, eosinophilia). Intravenous administration can cause phlebitis, thrombophlebitis, and pain along the vein, whereas intrathecal administration may lead to meningeal symptoms.

Polymyxin B is contraindicated in chronic renal failure, myasthenia gravis, Pregnancy, and Lactation.

The combination of polymyxin B with Aminoglycosides significantly increases the risk of oto- and nephrotoxicity as well as neuromuscular blockade. Polymyxin B must not be used in infusion sets containing Amino Acids, ampicillin, Cephalosporins, isotonic sodium chloride solution, Tetracyclines, or chloramphenicol due to pharmaceutical incompatibility.

Polymyxin M sulfate is used topically and orally. Topical administration (as a solution or liniment) is indicated for purulent wounds, infected Burns, ulcers, bedsores, inflammatory conditions of the eyes and ears, and abscesses caused by P. aeruginosa and other Gram-negative microflora. Polymyxin M sulfate tablets are prescribed for colitis, enterocolitis, and gastroenteritis caused by susceptible microflora, as well as for preoperative preparation of patients undergoing gastrointestinal surgery. The drug is never administered parenterally.

Renal function must be carefully monitored even when polymyxin preparations are administered topically or orally.

Gramicidin is active against streptococci, staphylococci, pneumococci, anaerobic pathogens, and other microorganisms. It is used exclusively topically (!) for washing and irrigating purulent wounds, bedsores, ulcers, as well as in Osteomyelitis, joint injuries, Empyema of the Pleura, complicated appendicitis, Phlegmon, carbuncles, and furuncles. Gramicidin paste is sometimes used for treating wounds and burns, or as a local contraceptive agent.