Time course toxic processes

The reader is referred to one of several texts giving detailed accounts of clinical pharmacokinetics. However, an understanding of the basic concepts is essential in order to appreciate how pharmacokinetic data can provide insight into the physiological processes, which determine the time course of a drug in the body, and implications this has for the toxicity and therapeutic efficacy of drugs, particularly the new active substances in development. 

Toxieokineties describes the processes associated with the time course of a xenobiotie along its pathway to its receptor site or sites. Generally, kinetics is the study of the time course of movement and the time course of chemical reactions including those processes associated with toxicity. In familiar terms, toxieokineties describes the processes that the body performs on the xenobiotie. 

Toxicokinetics is the quantitation of the time course of toxic substances in the body during the processes of absorption, distribution, biotransformation and excretion. The term originates from the Greek language toxicon ( poison ) and kinesis ( movement ). 

The flow rate and concentration of wastewater do not remain constant but vary during the course of the day and are also dependent on the time of year. If the flow rate is too high, loss of micro-organisms by washout may occur in secondary treatment processes. If the flow rate is too low, then the lack of nutrients will lead to a reduction of the micro-organism population. Wastewaters entering a treatment plant usually flow first into an equalisation basin, so that the flow rate out of the basin is maintained constant, or between prescribed limits, to protect the subsequent processes. The equalisation tank also reduces the effect of toxic shocks on the biological processes within the main treatment plant. 

Numerous foreign compounds enter a body in the course of time. This could be through inhalation, skin adsorption or, more importantly, the diet. Hydrophilic compounds can be easily excreted through bile in the faeces or through the kidney into the urine. The more lipophilic compounds are not so readily excreted and tend to accumulate in the fatty tissues of the body. This may lead to elevated and thereby toxic levels. Therefore excretion is preferable. To enhance this excretion, the molecule has to be made more hydrophilic. This process is called biotransformation. 

One of the reasons for this was, of course, the terrorist attacks on the United States on 11 September 2001. The effort to establish a global legal framework against terrorism and to enact counter-terrorism laws in many countries had a positive spin-off for the implementing legislation required under the Convention too. At the same time, the OPCW realized that its own (national as well as international) implementation process contributed to the counter-terrorism efforts, because it made toxic and precursor chemicals (and, of course, chemical weapons themselves) less accessible. ... 

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