16.6.2.3 Environmental Factors/Chemicals
The natural factors which affect the outcome of a biotransformation process can be
the presence of halogenated pesticides, polycyclic aromatic hydrocarbons; organophosphate insecticides, and heavy metals in the environment. The temperature,
altitude, atmospheric pressure, etc. are other forces which affect the process.
16.6.3 Biological Factors
16.6.3.1 Species Difference
Due to the difference in genetic makeup the drug metabolizing enzymes which are
controlled by genes differ from species to species.
Example Dogs are deficient in acetyltransferase and cats are deficient in
glucuronosyltransferase.
16.6.3.2 Strain Difference
The difference observed in response to the same drug within the individuals of the
same species is called pharmacogenetics. The strain difference is also termed as the
study of inter-subject variability in drug response. It can be monogenetically or
polygenetically controlled. In humans, polygenic control is observed in fraternal
twins, born from different eggs. But variations also arise due to ethnic cultural
differences.
16.6.3.3 Sex Difference
When the regulation of drug metabolism is controlled by sex hormones, it causes
variation in the process in different sexes of the studied population.
16.6.3.4 Age
As the body’s growth status is at a different page in different age groups, the process
of biotransformation varies among children, adults, and elderly. As mentioned
before, the neonates and infants have underdeveloped microsomal enzyme system
so they cannot metabolize commonly used drugs containing alcohol. But on the
other hand, children can metabolize some drugs faster than adults. Whereas in
elderly the reduced liver size and decreased hepatic blood flow also affect the
biotransformation process.
16.6.3.5 Diet
The type of food intake forms a very important factor which affects the enzyme
system in the body thereby affecting the whole process. The total protein intake;
protein–carbohydrate ratio; fat-free diet; dietary deficiency of vitamins and minerals;
starvation; alcohol ingestion are important parameters to consider for drug
metabolism.
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M. H. Yashavarddhan et al.
The natural factors which affect the outcome of a biotransformation process can be
the presence of halogenated pesticides, polycyclic aromatic hydrocarbons; organophosphate insecticides, and heavy metals in the environment. The temperature,
altitude, atmospheric pressure, etc. are other forces which affect the process.
16.6.3 Biological Factors
16.6.3.1 Species Difference
Due to the difference in genetic makeup the drug metabolizing enzymes which are
controlled by genes differ from species to species.
Example Dogs are deficient in acetyltransferase and cats are deficient in
glucuronosyltransferase.
16.6.3.2 Strain Difference
The difference observed in response to the same drug within the individuals of the
same species is called pharmacogenetics. The strain difference is also termed as the
study of inter-subject variability in drug response. It can be monogenetically or
polygenetically controlled. In humans, polygenic control is observed in fraternal
twins, born from different eggs. But variations also arise due to ethnic cultural
differences.
16.6.3.3 Sex Difference
When the regulation of drug metabolism is controlled by sex hormones, it causes
variation in the process in different sexes of the studied population.
16.6.3.4 Age
As the body’s growth status is at a different page in different age groups, the process
of biotransformation varies among children, adults, and elderly. As mentioned
before, the neonates and infants have underdeveloped microsomal enzyme system
so they cannot metabolize commonly used drugs containing alcohol. But on the
other hand, children can metabolize some drugs faster than adults. Whereas in
elderly the reduced liver size and decreased hepatic blood flow also affect the
biotransformation process.
16.6.3.5 Diet
The type of food intake forms a very important factor which affects the enzyme
system in the body thereby affecting the whole process. The total protein intake;
protein–carbohydrate ratio; fat-free diet; dietary deficiency of vitamins and minerals;
starvation; alcohol ingestion are important parameters to consider for drug
metabolism.
350
M. H. Yashavarddhan et al.