Vancomycin

Vancomycin is a glycopeptide antibiotic discovered as a penicillin substitute.

Indication.

Used against MRSA, Strep. viridans, Enterococcus and Cl. difficile.
Bactericidal action is exerted on gram-positive cocci, Neisseria, Clostridia and diphtheroids.
Gram-negative bacilli are non-responsive to the drug.

Mechanism of action.

Resistance.

Due to plasmid-mediated alteration of the dipeptide target site, hence a decrease in the affinity for the drug.

Adverse effects.

Nephrotoxicity and ototoxicity.
Super infections, vertigo and tinnitus.
Skin allergies include rashes, chills and fever.
Decreased blood pressure during intravenous injection.
Red man syndrome due to rapid intravenous injection causes chills, fever, urticaria and intense flushing.
Neutropenia, thrombocytopenia and eosinophilia.

Clinical uses.

The second choice drug to metronidazole for the antibiotic-associated pseudomembranous enterocolitis caused by C. difficile and given orally (125–500 mg 6 hourly).
Staphylococcal enterocolitis is an indication of oral vancomycin.
Alternative drug for serious skin, soft tissue and skeletal infections caused by gram-positive bacteria.
They are used in dialysis patients and those undergoing cancer chemotherapy.
They are used against Penicillin-resistant pneumococcal infections and infections caused by diphtheroids.
The preferred surgical prophylactic in MRSA prevalent areas and penicillin-allergic patients.

Dosage.