METABOLISM

Question 1

How can the drug be eliminated:

Answer 1

• Metabolism
• Excretion
• Redistribution

Question 2

Metabolism synonyms

Answer 2

Biotransformation

Question 3

Metabolism definition

Answer 3

Chemical alteration of the drug in the body. It is needed to inactivate the drug by making it ionized, water-soluble

Question 4

Sites of metabolism

Answer 4

• Liver
• Lung
• Kidney and skin
• GIT
• Plasma cholinesterase (ChE)

Question 5

Which drug is metabolised in the lung:

Answer 5

Nicotine

Question 6

Which drug is metabolised in the kidney and skin

Answer 6

Vitamin D

Question 7

Which drug is metabolised in the GIT:

Answer 7

Tyramine

Question 8

Which drug is metabolised by the plasma cholinesterase

Answer 8

Succinylcholine

Question 9

Types of metabolism in the liver

Answer 9

Phase I (non-synthetic)
Phase II (Synthetic, conjucation)

Question 10

What reactions happen in phase I

Answer 10

• Oxidation
• Reduction
• Hydrolysis

Question 11

What reactions happen in phase II

Answer 11

• Glucuronic acid
• Acetylation
• Methylation
• Glycine
• Sulfation

Question 12

Example of oxidation reaction

Answer 12

Ethyl alcohol —> acetaldehyde —-> acetic acid + H2O + CO2 + water

Question 13

Example of reduction reaction

Answer 13

Chloral hydrate —-> trichloroethanol

Question 14

Example of hydrolysis

Answer 14

Acetylcholine —-> acetic acid + choline

Question 15

Example of drugs metabolised by glucuronic acid:

Answer 15

Asprin
Morphine
Chloramphenicol

Question 16

Example of drugs metabolised by acetylation

Answer 16

Isoniazid
Procainamide
Hydralazine

Question 17

Example of drugs metabolised by methylation

Answer 17

Noradrenaline

Question 18

Example of drugs metabolised by addition of glycine

Answer 18

Asprin

Question 19

Example of drugs metabolised by sulfation

Answer 19

Steroids

Question 20

Results of phase I metabolism:

Answer 20

• Inactivation of drug
• Activation of inactive drug (prodrug)
• Maintain activation of the drug
• Toxication

Question 21

Results of phase II metabolism

Answer 21

Usually inactivation except morphine-6-glucuronide

Question 22

Most drugs enter Phase I then phase II while some drugs enter phase II directy like …..

Answer 22

Isoniazide

Question 23

Types of cellular enzymes

Answer 23

• Microsomal enzymes

- Non-microsomal enzymes

Question 24

Site of microsomal enzymes

Answer 24

In the sER or liver, kidney, lung and intestinal mucosa

Question 25

Sites of non-microsomal enzymes

Answer 25

Cytoplasm and mitochondria in all tissue

Question 26

Example of microsomal enzymes:

Answer 26

Monooxygenases, cytochrome P450, UGTs, epoxide hydrolases

Question 27

Examples of non-microsomal enzymes

Answer 27

The esterases, amidases, some flavoprotein oxidases and most conjugases

Question 28

What reactions does microsomal enzymes do?

Answer 28

Catalyze oxidation, reduction (phase I) and glucuronidation only (phase II)

Question 29

What reactions does non-microsomal enzymes do?

Answer 29

Oxidation, reduction, hydrolysis (phase I) | All phase II except glucuronidation

Question 30

Microsomal enzymes are inducible by ........

Answer 30

drugs, diet and genetics

Question 31

Non-microsomal enzymes are not inducible but

Answer 31

shows genitic variation

Question 32

Factors affecting hepatic microsomal enzymes

Answer 32

- Hepatic microsomal enzyme inducers - Hepatic microsomal enzyme inhibitors - Age - Disease - Genetic defect - Sex

Question 33

Hepatic microsomal enzyme inducers action

Answer 33

Increase metabolism of other drugs , decrease their action | Increase their own metabolism, causes tolerance

Question 34

Hepatic microsomal enzyme inducers examples

Answer 34

Phenobarbitone, phenytoin, carbamazepine, rifampicin, androgen and tobacco smoke

Question 35

Hepatic microsomal enzyme inhibitors types

Answer 35

Specific/Direct | Non-specific/ Indirect

Question 36

Specific hepatic microsomal enzyme inhibitors examples

Answer 36

Estrogen, cimetidine (ramitidine), valproic acid, erythromycin, ciprofloxacin, chloramphenicol.

Question 37

Non-specific hepatic microsomal enzyme inhibitors examples

Answer 37

Hepatotoxic drugs and drugs decreasing hepatic blood flow as propranolol and cimetidine.