Metabolism and pharmacokinetics of selected halon replacement candidates.

  title={Metabolism and pharmacokinetics of selected halon replacement candidates.},
  author={Darol E. Dodd and Wayne T. Brashear and Allen Vinegar},
  journal={Toxicology letters},
  volume={68 1-2},

Physiologically based pharmacokinetic analysis of the concentration-dependent metabolism of halothane.

A physiologically based pharmacokinetic model describing the concentration-dependent reduction in uptake and metabolism of halothane in male and female rats was developed and good simulation of urinary excretion data was interpreted to indicate that, when only 20% of the enzyme is inactivated, the rate of enzyme resynthesis was adequate to replenish enzyme activity within 24 h.

Hepatotoxicity in Guinea Pigs Following Acute Inhalation Exposure to 1,1-Dichloro-2,2,2-Trifluoroethane

Similarities in the response between halothane and HCFC-123 in this guinea pig model suggests that humans susceptible to halothanes-induced hepatitis may be susceptible to HCFC -123 by a common mechanism of toxicity.

Predicting the biodegradation products of perfluorinated chemicals using CATABOL

It was found that although the extent of biodegradation of parent compounds could reach 60%, persistent metabolites could be formed in significant quantities and a trend was observed where PFCs are transformed to more bioaccumulative and more toxic products.

The development of environmentally acceptable fluorocarbons

  • G. Rusch
  • Engineering
    Critical reviews in toxicology
  • 2018
The Montreal Protocol has been recognized as the most appropriate international treaty to phase-down HFCs and these new products were introduced within less than 10 years.

Organic Chlorofluoro Hydrocarbons

The chlorofluorocarbons (CFCs) were introduced in the 1930s as “safe” replacements for refrigerants such as sulfur dioxide, ammonia, carbon tetrachloride, and chloroform. In World War II, they were

Incorporation of Acute Dynamic Ventilation Changes into a Standardized Physiologically Based Pharmacokinetic Model

The combined TGAS-2P model provides a coupled, transient ventilation and pharmacokinetic response that predicts body mass normalized internal dose that is correlated with deleterious outcomes.

UV‐photoexcitation and ultrafast dynamics of HCFC‐132b (CF2ClCH2Cl)

The UV‐induced photochemistry of HCFC‐132b (CF2ClCH2Cl) was investigated by computing excited‐state properties with time‐dependent density functional theory (TDDFT), multiconfigurational second‐order

Metabolism of fluorine-containing drugs.

The strategic value of fluorine substitution in drug design is discussed in terms of chemical structure and basic concepts in drug metabolism and drug toxicity.



Metabolism in vivo and in vitro of the refrigerant substitute 1,1,1,2-tetrafluoro-2-chloroethane.

Formation of TFA and F- as products of oxidative HCFC-124 metabolism support the hypothesis that trifluoroacetyl fluoride is formed as an intermediate, and demonstrate that this halocarbon can be reductively metabolized.

Metabolite Identification of Halon Replacement Compounds.

Investigation of the metabolism of the Halon replacement candidates perfluorohexane (PFH) and the hydrochlorofluorocarbons (HCFCs) found the presence of trifluoroacetic acid indicates oxidative metabolism of HCFC-123 and IICFC-124, while Rats exposed to Halon 1211 had slightly elevated bromide levels in their urine.

Tissue acylation by the chlorofluorocarbon substitute 2,2-dichloro-1,1,1-trifluoroethane.

The present findings raise the possibility that humans exposed to HCFC-123 or structurally related HCFCs may be at risk of developing an immunologically mediated hepatitis.

Effects of exposure concentrations on distribution of halothane metabolites in the body.

Halothane is most susceptible to biodegradation to trifluoroacetic acid, but this pathway is saturated at very small exposure concentrations, and the contribution of each of the three metabolites to total metabolic clearance depends on exposure concentrations.

Volatile Metabolites and Decomposition Products of Halothane In Man

Under totally closed-circuit rebreathing conditions, the concentration of CF2CBrCl increased to 4–5 ppm, indicating significant breakdown of halothane by the soda lime, as well as clinical implications of these findings.

Toxicological evaluation of hydrochlorofluorocarbon 142b.

Volatile Metabolites of Halothane in the Rabbit

The present investigation suggests the possible existence of a previously unknown metabolic pathway of defluorination and debromination occurring in the early stage of halothane biotransformation.

Factors Affecting the Formation of Chlorotrifluoroethane and Chlorodifluoroethylene from Halothane

Measurement of these metabolic products in patients undergoing halothane anesthesia may permit rapid detection of an unusually high level of halothanes biotransformation along its hepatotoxic pathway.

Assessment of the reproductive toxicology of bromochlorodifluoromethane (BCF, halon 1211) in the rat.

It was concluded that bromochlorodifluoromethane had no reproductive toxicity potential in the rat.