Early authors suggested peak levels of 30 to 40 mg/L and trough levels of 5 to 10 mg/L,
but current recommendations are that peak levels need not be measured and that trough levels of 10 to 15 mg/L or 15 to 20 mg/L, depending on the nature of the infection and the specific needs of the patient, may be appropriate. Using measured vancomycin concentrations to calculate doses optimizes therapy in patients with augmented renal clearance. Biosynthesis
Vancomycin is made by the soil bacterium Amycolatopsis orientalis. Vancomycin biosynthesis occurs primarily via three nonribosomal protein syntheses (NRPSs) VpsA, VpsB, and VpsC. The enzymes determine the amino acid sequence during its assembly through its 7 modules. Before vancomycin is assembled through NRPS, the non-proteinogenic amino acids are first synthesized. L-tyrosine is modified to become the β-hydroxytyrosine (β-HT) and 4-hydroxyphenylglycine (4-Hpg) residues. 3,5 dihydroxyphenylglycine ring (3,5-DPG) is derived from acetate. Nonribosomal peptide synthesis occurs through distinct modules that can load and extend the protein by one amino acid per module through the amide bond formation at the contact sites of the activating domains. Each module typically consists of an adenylation (A) domain, a peptidyl carrier protein (PCP) domain, and a condensation (C) domain. In the A domain, the specific amino acid is activated by converting into an aminoacyl adenylate enzyme complex attached to a 4phosphopantetheine cofactor by thioesterification The complex is then transferred to the PCP domain with the expulsion of AMP. The PCP domain uses the attached 4-phosphopantethein prosthetic group to load the growing peptide chain and their precursors.
Active bacterial infections may be treated with a topical antibiotic or a combination antibiotic-steroid eye drop, such as tobramycin/dexamethasone (Tobradex). An oral tetracycline antibiotic (such as doxycycline) may be used in systemic or particularly severe/intractable infections. Erythromycin may be an effective alternative, especially in pediatric cases where the side effects of tetracyclines are unacceptable.Artificial tears can reduce dryness and discomfort from corneal lesions. Photophobic discomfort can be mitigated with dark sunglasses. See also
Blepharitis
Allergic conjunctivitis
Conjunctivitis
Keratitis
Keratoconjunctivitis
Corneal abrasion


== References ==