Explore BrainMass

Explore BrainMass

    Absorption, Distribution, Metabolism and Elimination

    Absorption, distribution, metabolism and elimination are the major steps involved in what can be referred to as the life cycle of a drug. Once a drug enters the human body, it follows a particular pathway which eventually leads to the elimination of the drug.

    Absorption is the first step and is linked to the process of drug liberation. Drug liberation is necessary for oral drugs and refers to the mechanism of a drug in pill form being released from its capsule or tablet. The drug must undergo disintegration and dissolution before absorption occurs. For liquids taken orally, it refers to the process of the drug dissolving with the fluids of the digestive system. Absorption can take other routes other than the mouth, for example, gases are absorbed by the lungs. Furthermore, the time it takes for absorption depends upon the concentration of the drug being administered.

    Absorption, distribution and elimination are all similar in that they require membranes to be passed by the drug. Remember that membranes are lipid in nature. The processes by which membranes can be crossed are:

    • Passive diffusion
    • Filtration via pores
    • Active transport
    • Pinocytosis

    Distribution refers to the perfusion of a drug into the appropriate organ or tissue. This usually requires the binding of a drug to a receptor and the ability of the drug to cross a membrane. Once the drug has accumulated into the site of interest, metabolism is the next step. Metabolism is also referred to as biotransformation and takes place in the liver. This usually results in the transformation of the drug into a less active chemical which can be eliminated from the body through the kidney, the final step. Additionally, drug interactions, particular foods and diseases, such as liver disease, can interfere with the process of elimination, causing a drug to have a longer effect than intended. 


    © BrainMass Inc. brainmass.com May 24, 2024, 11:24 pm ad1c9bdddf

    BrainMass Solutions Available for Instant Download

    A solution for Allosterity and Cooperativity

    When a compound made up of non-polar molecules is mixed with an aqueous solvent such as water, the molecules cluster together into a ball while water tends to form a ring around them. They do so because they are hydrophobic (. Wikibooks 2015). When more of this solute is added, the water ring is disturbed as more of the hydro

    Chemical-genetic study design elucidate Downstream Signal Chain

    Imatinib is successful in treating BCR-ABL-positive chronic myelogenous leukemia (CML) patients. This is achieved by suppressing the expansion of BCR-ABL-positive bone marrow cells present in the patients. Besides BCR-ABL, imatinib also inhibits KIT, a receptor tyrosine kinase that can be activated by BCR-ABL and a positive regu

    A solution for Allosterity and Cooperativity

    1. Explain in your own words why increasing the hydrophobicity of a drug leads to "entropic optimization" of the binding affinity. Please consider all of the entropic changes that occur in drug binding and how they alter affinity. 2. What are the limitations of this approach to affinity optimization? 3. Please identify some ot

    The Mechanism of Opioid Tolerance

    Observation: People who are treated for pain with morphine often need larger doses over time to inhibit their pain. This is called opioid tolerance. You laboratory is interested in understanding the cellular mechanism underlying this decrease in morphine's effects, particularly whether G-protein signaling or beta-arrestin signal

    Getting Word Out about Flu Vaccination

    See the attached file. Brochure Outline - Influenza A Vaccines Title: Getting The Word Out About Flu Vaccination Group 3 BIOL 302 Bacteria, Viruses, and Health *PLEASE FEEL FREE TO ADD, TAKE OUT, SUGGEST, ALTER Introduction The purpose of the Group 3 project 2 assignment will be to create an informational pamphlet t

    Birth Control Methods

    Below is a set of six general categories of birth control that you will evaluate for your classmates: Pills/patches/rings (estrogen + progestin based) Sympto-thermal + condom/diaphragm Intra-uterine devices (such as ParaGard, Mirena) Surgical - vasectomy (male sterilization) Surgical - tubal ligation

    How drugs for leukemia are broken down in the body.

    A drug used for leukemia is not broken down in the stomach and is well absorbed by the intestine. However, the molecular form of the drug collected from the blood is not the same as the form that was swallowed by the patient. What explanation is most likely?

    Correlation Between Blood Pressure and New Medication

    To complete this exploration you will continue to utilize the Mastering Biology companion Web site. Complete the activity: GraphIt!: An Introduction to Graphing, including answering the tutorial questions to build your understanding. Create and describe a data set including independent and dependent variables (be creative) an