Search results
Results from the WOW.Com Content Network
Intravascular administration does not involve absorption, and there is no loss of drug. [4] The fastest route of absorption is inhalation. [5] Absorption is a primary focus in drug development and medicinal chemistry, since a drug must be absorbed before any medicinal effects can take place. Moreover, the drug's pharmacokinetic profile can be ...
ADME is the four-letter abbreviation (acronym) for absorption, distribution, metabolism, and excretion, and is mainly used in fields such as pharmacokinetics and pharmacology. The four letter stands for descriptors quantifying how a given drug interacts within body over time.
Distribution in pharmacology is a branch of pharmacokinetics which describes the reversible transfer of a drug from one location to another within the body.. Once a drug enters into systemic circulation by absorption or direct administration, it must be distributed into interstitial and intracellular fluids.
Whether a drug is taken with or without food will also affect absorption, other drugs taken concurrently may alter absorption and first-pass metabolism, intestinal motility alters the dissolution of the drug and may affect the degree of chemical degradation of the drug by intestinal microflora.
Example: cimetidine; The absorption is limited by the permeation rate but the drug is solvated very fast. If the formulation does not change the permeability or gastro-intestinal duration time, then class I criteria can be applied. Class IV – low permeability, low solubility . Example: bifonazole; Those compounds have a poor bioavailability.
The model outputs for a drug can be used in industry (for example, in calculating bioequivalence when designing generic drugs) or in the clinical application of pharmacokinetic concepts. Clinical pharmacokinetics provides many performance guidelines for effective and efficient use of drugs for human-health professionals and in veterinary medicine .
An example of a drug where first-pass metabolism is a complication and disadvantage is in the antiviral drug remdesivir. Remdesivir cannot be administered orally because the entire dose would be trapped in the liver with little achieving systemic circulation or reaching target organs and cells (for example, cells infected with SARS-CoV-2 ).
Drug administration via the nasal cavity yields rapid drug absorption and therapeutic effects. [33] This is because drug absorption through the nasal passages does not go through the gut before entering capillaries situated at tissue cells and then systemic circulation and such absorption route allows transport of drugs into the central nervous ...