1. The extent of drug-protein binding can change with both changes in protein and drug concentration.
a) True
b) False
Explanation: The concentration of drug that binds to HSA do not have much influence on HA, since any concentration of drug in less than the concentration of HSA. The therapeutic concentration of lidocaine can saturate AAG with which it binds as the concentration of AAG is much less in comparison to that of HSA in blood.
2. In the equation X= Vd C, what does X stands for?
a) Amount of drug in the blood
b) Amount of drug in plasma
c) Amount of drug in the tablet
d) Amount of drug in the body
Explanation: The relationship between tissue-drug binding and apparent volume of distribution can be established as Vd = amount of drug in the body (X)/ Plasma drug concentration (C).
3. Only unbound or free drug is capable of being eliminated.
a) True
b) False
Explanation: Unbound or free drug is capable of being eliminated. Because the drug-protein complex cannot penetrate into the metabolizing organ. The large molecular size of the complex also prevents it from getting filtered through the glomerulus.
4. Penicillin has short plasma half-life although it can bind to plasma protein rigidly.
a) True
b) False
Explanation: Penicillin has a short plasma half-life. Though it can rigidly bind to the plasma still it has short elimination half live. This is because equilibration occurs between the free and the bound protein and the free drug is equally rapidly excreted by active secretion in renal tubules.
5. Displacement interactions are significant in the case of drugs which are more than 95% bound.
a) True
b) False
Explanation: A displacement of 1% and 99% bound drug results in doubling of the free drug concentration i.e. a 100% rise. For a drug which is bound to 99% and a displacement of 1% results in only a 10% rise in freed rug concentration which may be insignificant clinically.
6. . Which of the following is a correct method to find the fraction of unbound drug in plasma? Given where Cu is the concentration of unbound drug and C is total plasma drug concentration.
a) CuC
b) C / Cu
c) Cu/C
d) 1/C Cu
Explanation: The fraction of unbound drug can be calculated with the formula fu = Cu/C, where Cu is the concentration of unbound drug and C is total plasma drug concentration and fu is the unbound drug.
7. Biotransformation of drugs is defined as the conversion from one physical form to another.
a) True
b) False
Explanation: Biotransformation of drugs is the conversion of drugs from one chemical form to another. The term is used with metabolism. The chemical changes are usually affected by enzymatically in the body. For example conversion of penicillin to penicilloic acid by bacterial penicillinase
8. What are xenobiotics?
a) Another form of antibiotics
b) A form of nutrient
c) Nutrients which kill the gut harmful microbes
d) Anything that is not nutrients and enters the body through different routes
Explanation: All chemical substances that are not nutrients for the body and enter the body through different routes like inhalation, ingestion, absorption, etc. are known as xenobiotics. Drugs are also known as xenobiotics.
9. The drug biotransformation is a detoxification process.
a) True
b) False
Explanation: The body’s metabolic system does not allow any drug to accumulate or aggregate inside the body. Water soluble agents are excreted via urination. The metabolic system transforms the water-insoluble drugs to polar and so that it can easily be urinated
10. What is the active form of salicylic acid?
a) Sialic acid
b) Salic acid
c) Salicylic acid
d) Salicycle acid
Explanation: The salicylic acid is given to a patient on in its inactive form. Through metabolism, this inactive salicylic acid is converted into its active form of Salicylic acid.