Question

Compare and contrast pharmacokinetic, pharmacodymanic and conditioned drug tolerance, including examples of each.

** Needs to be a full paragraph, please do not answer unless you can do so fully**

Answer 1

Drug tolerance is the concept that occurs when a drug becomes less effective after being present in the body over a long period of time i.e. after repeated intake of the drug.

Pharmacological drug tolerance is the drug tolerance that develops from the repeated intake of the drug and thus the body becoming less sensitive to the drug. The reason being the constant interaction between the high concentration of the drug with the target site where it is constantly binding. The other reason being a decrease in the target sites. Some other substances might be binding to the particulat target sites. The alternative is increased use of the drug so that more drug is present to bind with the available target sites.Example:methadone affecting a person getting over heroin addiction. When the body has become less sensitive after repeated use of heroin, methadone use is affcting the person.

Pharmakokinetic drug tolerance occurs due to lesser amount of drug reaching the target sites. The drugs are absorbed in the bloodstream to be transported to the target sites, but all of them donot bind because the body has proteins called enzymes whioch degrades the drug.Ex.CYP450 enzymes are required to degrade sustances such as ethanol.

Conditioned tolerance occurs due to the behavioural effect of the drug. It is the previously learned response to the neutral stimulus. If the smell of food is unconditioned strimilus, the feeling of hunger is unconditioned stimulus, the reaction i.e the blow of whistle is conditioned stimulus.