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15 Cards in this Set
- Front
- Back
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What happens when we try to get rid of a lipophilic drug by the kidney? |
Nothing, it gets reabsorbed and cannot be excreted by the kidney. Only hydrophilic substances can be excreted by that route. |
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How do we convert a drug into a hydrophilic compound? |
We undergo a phase I & II reaction |
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What is true about the existence of enzymes in the body that can break down drugs in relation to our evolution? |
We evolved to be able to break down xenobiotic compounds. |
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What are the possible end results of drug metabolism in terms of functionality in the body? |
Inactive metabolite (action of drug terminated) Active metabolite (continuation of drug action) Toxic metabolite (product is more dangerous)
Active metabolite (drug was given in the proform) |
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Does 1 drug = 1 metabolite? |
No, there can be many products depending on the dosage and the other factors altering how the drug is metabolized. |
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What does it mean to say "first past effect"? |
It means that if the hydrophilic drug is rapidly metabolized by the liver it cannot be given in the oral form because the blood from the intestines goes direct to the liver and the drug will be rapidly metabolized before disseminating out to the rest of the body. |
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Where are most of the drug metabolizing enzymes housed? |
In or on the endoplasmic reticulum membranes of the hepatocytes. |
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What is one way in which a drug can be modified by a phase I reaction? |
Oxidation by the addition of oxygen typically through the Cyp P450 system. |
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Where are the non-CYP P450 enzymes housed? |
They are in the cytosol not attached to the membrane of the ER. |
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In addition to oxidation as a phase I reaction, what other modification can be made to the drug? |
Reduction |
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What is the last method that a drug can be modified by phase I reaction that is less common? |
Hydrolysis |
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What is the purpose of the phase II reaction? |
To add a group to the drug that will still further increase the hydrophilicity of the drug so that it will be eliminated. |
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What type of compounds can be added via a phase II reaction to a drug to increase the hydrophilicity? |
Sugars, acids, etc that have a high degree of polarity. |
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If a drug is metabolized but it is not by a phase I or a phase II reaction, what can this reaction be classified into? |
A non-enzymatic reaction |
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What type of considerations should be made when considering drug metabolism rates? |
Genetics (polymorphisms) Gender/race Age Disease state Drug interactions (that alter enzyme kinetics) Tolerance formation (induction of enzyme production by the chronic presence of a toxin) |
