This means that people receiving intravenous linezolid may be switched to oral linezolid as soon as their condition allows it, whereas comparable antibiotics (such as vancomycin and quinupristin/dalfopristin) can only be given intravenously. Taking linezolid with food somewhat slows its absorption, but the area under the curve is not affected.Linezolids plasma protein binding is approximately 31% (range 4–32%) and its volume of distribution at steady state averages 36.1–47.3 liters in healthy adult volunteers. Peak plasma concentrations (Cmax) are reached one to two hours after administration of the drug. Linezolid is readily distributed to all tissues in the body apart from bone matrix and white adipose tissue. Notably, the concentration of linezolid in the epithelial lining fluid (ELF) of the lower respiratory tract is at least equal to, and often higher than, that achieved in serum (some authors have reported bronchial fluid concentrations up to four times higher than serum concentrations), which may account for its efficacy in treating pneumonia. However, a meta-analysis of clinical trials found that linezolid was not superior to vancomycin, which achieves lower concentrations in the ELF. Cerebrospinal fluid (CSF) concentrations vary; peak CSF concentrations are lower than serum ones, due to slow diffusion across the blood–brain barrier, and trough concentrations in the CSF are higher for the same reason. The average half-life is three hours in children, four hours in teenagers, and five hours in adults.Linezolid is metabolized in the liver, by oxidation of the morpholine ring, without involvement of the cytochrome P450 system.
Zinc gluconate is the zinc salt of gluconic acid. It is an ionic compound consisting of two anions of gluconate for each zinc(II) cation. Zinc gluconate is a popular form for the delivery of zinc as a dietary supplement providing 14.35% elemental zinc by weight. Gluconic acid is found naturally, and is industrially made by the fermentation of glucose, typically by Aspergillus niger, but also by other fungi, e.g. Penicillium, or by bacteria, e.g. Acetobacter, Pseudomonas and Gluconobacter. In its pure form, it is a white to off-white powder. It can also be made by electrolytic oxidation, although this is a more expensive process. The advantages are a lower microbiological profile, and a more complete reaction, yielding a product with a longer shelf life. Zinc gluconate and the common cold
Zinc gluconate has been used in lozenges for treating the common cold. However, controlled trials with lozenges which include zinc acetate have found it has the greatest effect on the duration of colds. Zinc has also been administered nasally for treating the common cold, but has been reported to cause anosmia in some cases. Safety concerns
Instances of anosmia (loss of smell) have been reported with intranasal use of some products containing zinc gluconate. In September 2003, Zicam faced lawsuits from users who claimed that the product, a nasal gel containing zinc gluconate and several inactive ingredients, negatively affected their sense of smell and sometimes taste. Some plaintiffs alleged experiencing a strong and very painful burning sensation when they used the product.