What is plasma protein binding of drugs?
What is plasma protein binding of drugs?
Plasma protein binding refers to the degree to which medications attach to proteins within the blood. A drug’s efficiency may be affected by the degree to which it binds. The less bound a drug is, the more efficiently it can traverse cell membranes or diffuse.
Why is plasma protein binding important in drugs?
Plasma proteins, by virtue of their high concentration, control the free drug concentration in plasma and in compartments in equilibrium with plasma, thereby, effectively attenuating drug potency in vivo.
How does plasma protein binding affect drug distribution?
Protein-binding may affect drug activity in one of two ways: either by changing the effective concentration of the drug at its site of action or by changing the rate at which the drug is eliminated, thus affecting the length of time for which effective concentrations are maintained.
What factors affect protein binding?
Protein binding by this method can be affected by drug stability, radioactive tracer purity, time of equilibration, dilution, temperature, pH, buffer composition, and colloidal osmotic fluid shifts caused by plasma proteins.
What is protein binding and its significance?
Abstract. Serum protein binding of antimicrobials can reduce antimicrobial activity, restrict tissue distribution, and delay drug elimination. Binding percentages of 80 per cent or more have the potential to significantly reduce free drug levels and affect therapeutic efficacy in patients.
What happens plasma protein binding?
Drugs can bind extensively to plasma proteins. The free (unbound) fraction of a drug is usually the portion that exerts a pharmacologic effect. If protein binding is reduced, a greater free fraction is available for any given total drug concentration, which may increase drug activity.
How does protein binding affect the pharmacological response of a drug?
Many drugs interact with proteins to form reversible drug- protein complexes. Such complexes have different properties from the free (unbound) drug and, consequently, protein binding can influ- ence both the pharmacokinetic and pharmacodynamic characteristics of drugs.
What is the impact of protein binding on drug levels and dosing?
A change in protein binding causes a clinically important change in the relationship between total and unconjugated concentrations of the drug. Thus, blood proteins have critical effects on individual drug doses regimes and the efficacy of antiviral therapy for HIV-infected patients [3,7-10].
What are the factors affecting protein drug binding?
Factors Affecting Protein-Drug Binding
- Factors affecting protein-drug binding can be broadly categorized as—
- Drug related factors.
- a. Physicochemical characteristics of the drug.
- b. Concentration of drug in the body.
- c. Affinity of a drug for a particular binding component.
- Protein/tissue related factors.
- a.
- b.
What is the mechanism of protein binding?
The phenomenon of complex formation with proteins is called as protein binding of drugs. 1. Intracellular binding – where the drug is bound to a cell protein which may be the drug receptor; if so, binding elicits a pharmacological response.
Which drug has high plasma protein binding?
Warfarin
Examples of compounds with different volume of distribution
| Drug | VD | Comments |
|---|---|---|
| Warfarin | 8L | Reflects a high degree of plasma protein binding. |
| Theophylline | 30L | Represents distribution in total body water. |
| Chloroquine | 15000L | Highly lipophilic molecules which partitions into body fat |
| NXY-059 | 8L | Highly-charged hydrophilic molecule. |
What are the methods for studying drug protein binding?
The qualitative and quantitative aspects of capillary electrophoretic methods used to study drug-protein interactions, viz. the affinity capillary electrophoresis (ACE). Hummel-Dreyer (HD), frontal analysis (FA), vacancy peak (VP) and vacancy affinity capillary electrophoresis (VACE) methods have been investigated.
