Pharmacokinetics is described as the study of how our body responds to a drug. Pharmakon means a drug, and kinetics means moving. This study involves the movement of narcotics concerning time, distribution, absorption, metabolism, excretion, and bioavailability.
It also involves the study of formulas obtains in experiments with different drugs.
Pharmacokinetics of drug varies with each patient, depending on their medical history, age, genetic function, obesity, renal function, sex, and chemical composition. Let’s understand this with an example; each drug has a different half-life duration. This duration depends on both excretion and metabolism. If a person has good metabolism, then he will reflect more effective results of the particular drug. Thus the pharmacokinetics of the drug varies with each patient.
Due to differences in persons, the drug is being prescribed according to its need. If the dosage is not adjusted accordingly, it might adversely affect. Pharmacokinetics plays an essential role in applying medications and their dosage that results rapidly, accurately, and effectively.
The pharmacokinetics model has two methods: non-compartmental or compartmental methods.
It estimates the drug’s exposure by calculating the area under the curve of a concentration-time graph. They are almost more versatile. The final result of transformation when a person consumes the drug depends on interrelated factors.
These estimate the concentration-time curve using kinetics. Many functional methods have been discovered to study pharmacokinetics.
Each method does not reflect the mechanism’s actual situation, but they are almost accurate. For example, our body has tissues that help in blood flow. But the volume of tissues differs in each part of the body. This difference can also be shown in the drug’s distribution, somewhere greater and somewhere lesser.
Concepts in Clinical Pharmacokinetics
It is vital to understand kinetic homogeneity for assumptions in clinical pharmacokinetics. It is the base of various therapeutic and plasma drug compositions being confirmed and accepted. While studying the structure of drugs, and assumptions are made that plasma directly relates to tissues, where modification in the treatment of drug is made similar to Parkinson’s disease in osteomyelitis.
Principles of pharmacokinetics
There are mainly five principles as listed below:
It is a process of releasing drug-using pharmaceutical formulation.
In this process, the drug enters where blood circulates.
It is the dissemination or dispersion of substance in tissues and fluids throughout the body.
It is also called inactivation or biotransformation. It is the process of the recognition that an unknown substance is available.
It is the process of removal of substances out of the body.
Analysis of pharmacokinetic
Its research is used to determine the following
- Characterize drug exposure: Apart from few drugs, a portion of the drug’s dose is absorbed and always pharmacologically active.
- Predict dosage requirements: It helps analyze the accurate dosage of any drug for each person.
- Assess changes in dosage requirement: It is mandatory to check the dosage or overdosage required biologically and to make changes accordingly.
- Estimate absorption and elimination rate: Knowing when to take the drug and when to not helps in formulation design.
- Relative bioavailability or bioequivalence: Knowing the new accumulation of any drug creates therapeutic advantages.
- Understanding concentration-effect relationship: Identifying variables affecting its relationship will prove pharmacokinetic successful.
- Establish efficacy characteristics and safety margins.
Frequently asked question
What are pharmacokinetic factors?
There are majorly four factors: water-solubility, molecular weight, dissociation degree, and fat-soluble.
What are pharmacokinetic properties and parameters?
Its parameters are as follows:
- Absorption rate constant
- The apparent volume of distribution
- Unbound fraction
- Rate of elimination
- Metabolic clearance
- Renal clearance
- Fraction excreted unchanged
- Elimination rate constant
- Biologic half-life
What are the examples of pharmacokinetics?
Digoxin are one of the best example of pharmacokinetics.