Drug Biotechnology Multiple Choice Questions on “Tissue Binding of Drugs”.
1. What reasons make tissue-drug binding important for drug distribution?
a) Increases the volume of distribution of drugs and results in localization of drug at a specific site
b) Increases the volume of distribution of drugs
c) Results in localization of drugs at a tissue specific site
d) Increases in absorption from the tissue due to concentration increasing
Answer: a
Clarification: Tissue-drug binding is important in the distribution of drugs. This is because it increases the apparent volume of distribution of drugs in contrast to plasma protein which decreases it. Tissue-drug binding results in localization of the drug at a specific site in the body.
2. Following is the order in decreasing order of drug binding to the extravascular tissue. Which one is the correct order?
a) Liver > kidney > muscle > lung
b) Liver > muscle > lung > kidney
c) Liver > muscle > kidney > lung
d) Liver > kidney > lung > muscle
Answer: d
Clarification: Factors influencing localization of drugs are tissues lipophilicity, structure of drug, perfusion rate, pH differences etc. Drugs binding to the extracellular site has the order of binding in decreasing order liver > kidney > lung > muscle.
3. What is the relation between halogenated hydrocarbon and liver?
a) Halogenated hydrocarbon is a drug for liver problems
b) Halogenated hydrocarbon is nutrition for liver
c) Halogenated hydrocarbon causes hepatotoxicity
d) Halogenated hydrocarbon forms the bile juices in liver
Answer: c
Clarification: Epoxides of number of Halogenated hydrocarbon and paracetamol bind irreversibly to the liver tissues resulting in hepatotoxicity. Thus we are told that taking more paracetamol can damage our liver.
4. Which drugs accumulate in liver?
a) Acidic drugs like imipramine
b) Basic drugs like imipramine
c) Halogenated hydrocarbons
d) Chloroquinine
Answer: b
Clarification: Imipramine is a basic drug. Basic drug like imipramine, chlorpromazine and anti-histamines accumulate in lungs.
5. Which metals get accumulated in the kidney?
a) Mercury, cadmium, lead
b) Mercury, cadmium, iron
c) Mercury, lanthanum, lead
d) Mercury, cadmium, fluoride ions
Answer: a
Clarification: Metallothionin, is a protein present in kidneys. This protein tends to bind to heavy metals such as mercury, cadmium, lead. Resulting in their accumulation in kidney and toxicity.
6. Which of the following drugs accumulate in skin?
a) Acidic drugs like imipramine
b) Basic drugs like imipramine
c) Halogenated hydrocarbons
d) Chloroquine
Answer: d
Clarification: Skin as melanin which protects us from the harmful UV rays of the sun. Chloroquine and phenothiazines accumulate in skin by interacting with melanin.
7. Which of the following drugs are responsible for retinopathy?
a) Acidic drugs like imipramine
b) Basic drugs like imipramine
c) Halogenated hydrocarbons
d) Chloroquinine
Answer: d
Clarification: Chloroquine and phenothiazines accumulate in skin by interacting with melanin. Since our retinal pigment of eye also has melanin, binding of chloroquine and phenothiazines to it is responsible for retinopathy.
8. Which drugs deposit in hair shafts?
a) Arsenicals
b) Tetracycline
c) Halogenated hydrocarbons
d) Lipophilic drug
Answer: a
Clarification: Arsenicals, chloroquine, phenothiazines are reported to deposit in hair shaft. Tetracycline binds to bones and teeths. Lipophilic drugs accumulate in adipose tissues. Epoxides of number of Halogenated hydrocarbon and paracetamol bind irreversibly to the liver tissues resulting in hepatotoxicity.
9. Which drug causes brown yellow discoloration of infant’s teeth?
a) Arsenicals
b) Tetracycline
c) Halogenated hydrocarbons
d) Lipophilic drug
Answer: b
Clarification: Tetracycline, this drug tends to bind to bones and teeth. Administration of this antibiotic to infants or children during odontogenesis results in permanent brown yellow colour discoloration of teeth.
10. Which drug accumulate in adipose tissue?
a) Arsenicals
b) Tetracycline
c) Halogenated hydrocarbons
d) Lipophilic drug
Answer: d
Clarification: Lipophilic drugs such as that of thiopental and pesticides such as DDT accumulate in adipose tissue. Halogenated hydrocarbon and paracetamol bind irreversibly to the liver tissues resulting in hepatotoxicity. Tetracycline tends to bind to bones and teeth.
11. Which drugs results in distortion of double stranded DNA structure?
a) Arsenicals
b) Quinacrine
c) Halogenated hydrocarbons
d) Lipophilic drug
Answer: b
Clarification: DNA interacts with drugs like Chloroquine and Quinacrine. These drugs result in distortion of the double stranded helical structure of the DNA.