Pharmacokinetics
Levofloxacin is rapidly and essentially completely absorbed after oral administration, with a plasma concentration profile over time that is essentially identical to that obtained from intravenous administration of the same amount over 60 minutes. As such, the intravenous and oral formulations of levofloxacin are considered interchangeable. Levofloxacins ability to bind to proteins in the body ranges from 24 to 38%.The drug undergoes widespread distribution into body tissues. Peak levels in skin are achieved 3 hours after administration and exceed those in plasma by a factor of 2. Similarly, lung tissue concentrations range from two-fold to five-fold higher than plasma concentrations in the 24 hours after a single dose. The mean terminal plasma elimination half-life of levofloxacin ranges from approximately 6 to 8 hours following single or multiple doses of levofloxacin given orally or intravenously. Elimination occurs mainly via excretion of unmetabolized drug in the urine. Following oral administration, 87% of an administered dose was recovered in the urine as unchanged drug within 2 days. Less than 5% was recovered in the urine as the desmethyl and N-oxide metabolites, the only metabolites identified in humans. Chemistry
Like all fluoroqinolones, levofloxacin is a fluorinated quinolone carboxylic acid. It is a chiral molecule and the pure (−)-(S)-enantiomer of the racemic drug ofloxacin. This enantiomer binds more effectively to the DNA gyrase enzyme and to topoisomerase IV than its (+)-(R)-counterpart.
Congenital syphilis is syphilis present in utero and at birth, and occurs when a child is born to a mother with syphilis. Untreated early syphilis infections results in a high risk of poor pregnancy outcomes, including saddle nose, lower extremity abnormalities, miscarriages, premature births, stillbirths, or death in newborns. Some infants with congenital syphilis have symptoms at birth, but many develop symptoms later. Symptoms may include rash, fever, an enlarged liver and spleen, and skeletal abnormalities. Newborns will typically not develop a primary syphilitic chancre but may present with signs of secondary syphilis (i.e. generalized body rash). Often these babies will develop syphilitic rhinitis ("snuffles"), the mucus from which is laden with the T. pallidum bacterium, and therefore highly infectious. If a baby with congenital syphilis is not treated early, damage to the bones, teeth, eyes, ears, and brain can occur. Classification
Early
This is a subset of cases of congenital syphilis. Newborns may be asymptomatic and are only identified on routine prenatal screening. If not identified and treated, these newborns develop poor feeding and runny nose. By definition, early congenital syphilis occurs in children between 0 and 2 years old. After, they can develop late congenital syphilis. Late
Late congenital syphilis is a subset of cases of congenital syphilis.