The anti-anabolic action of the tetracyclines may cause an increase in BUN. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. As with standardized dilution techniques, diffusion methods require the use of laboratory control microorganisms that are used to control the technical aspects of the laboratory procedures. Standardized susceptibility test procedures require the use of laboratory control microorganisms to control the technical lai vai nopirkt minocycline online klinika aspects of the laboratory procedures. This tetracycline toxicity is probably caused by anhydro-4-epitetracycline, degradation product that is formed when the drug is stored for long periods or kept in moist environment. While this is not problem in those with normal renal function, in patients with significantly impaired function, higher serum levels of tetracycline may lead to azotemia, hyperphosphatemia, and acidosis. Does not endorse and is not responsible for the accuracy of the content, or for practices or standards of non-Merck sources.