A double mutant form of S. pneumoniae Gyr A + Par C bearing Ser-81-->Phe and Ser-79-->Phe mutations were eight to sixteen times less responsive to ciprofloxacin. Contraindications and interactions
Package inserts mention that levofloxacin is to be avoided in patients with a known hypersensitivity to levofloxacin or other quinolone drugs.Like all fluoroquinolines, levofloxacin is contraindicated in patients with epilepsy or other seizure disorders, and in patients who have a history of quinolone-associated tendon rupture.Levofloxacin may prolong the QT interval in some people, especially the elderly, and levofloxacin should not be used for people with a family history of Long QT syndrome, or who have long QT, chronic low potassium, it should not be prescribed with other drugs that prolong the QT interval.Unlike ciprofloxacin, levofloxacin does not appear to deactivate the drug metabolizing enzyme CYP1A2. Therefore, drugs that use that enzyme, like theophylline, do not interact with levofloxacin. It is a weak inhibitor of CYP2C9, suggesting potential to block the breakdown of warfarin and phenprocoumon. This can result in more action of drugs like warfarin, leading to more potential side effects, such as bleeding.The use of non-steroidal anti-inflammatory drugs (NSAIDs) in combination with high dose fluoroquinolone therapy may lead to seizures.When levofloxacin is taken with anti-acids containing magnesium hydroxide or aluminum hydroxide, the two combine to form insoluble salts that are difficult to absorb from the intestines. Peak serum concentrations of levofloxacin may be reduced by 90% or more, which can prevent the levofloxacin from working.
Linear gingival erythema (LGE) is a periodontal disorder diagnosed based on distinct clinical characteristics. It was originally thought that LGE was directly associated with HIV, and it was thus called HIV-associated gingivitis (HIV-G). Later research confirmed that LGE also occurs in HIV negative immunocompromised patients, and it was thus renamed. Presentation
LGE is limited to the soft tissue of the periodontium, appearing as a red line 2–3 mm in width adjacent to the free gingival margin. Unlike conventional periodontal disease, though, LGE is not significantly associated with increased levels of dental plaque.The prevalence of LGE remains unclear and there is no known treatment. == References ==