Fundamentals Of Pharmacology

Question 1

Cytochrome p450

Answer 1

Superfamily of enzymes involved in drug metabolism and bioactivation. It is a membrane associated protein that present in most tissues

Question 2

Function of cytochrome p450

Answer 2

Plays important roles in hormone synthesis and breakdown, cholesterol synthesis, and vitamin D metabolism

Question 3

P450 inhibitors

Answer 3

Drugs that decrease the activity of cytochrome p450

Question 4

What happens if cytochrome p450 is inhibited

Answer 4

Drugs metabolized by p450 are metabolized at a decreased rate.

Question 5

Example of p450 inhibitors

Answer 5

Cimetidine, ketoconazole, erythromycin, ciprofloxacin, Indinavir, acute alcohol use, isoniazid, grapefruit juice, quinidine, sulfonamides

Question 6

Quinidine

Answer 6

Class I anti-arrhythmic agent that acts on fast inward currents

Question 7

Ciproflaxin

Answer 7

A fluoroquinolone antibiotic that is commonly used for gram negative rod infections of the urinary and GI tracts. It works by interfering with topoisomerase II

Question 8

Isoniazid

Answer 8

Decreases the synthesis of myopic acids, which is a key component of mycobacterium tuberculosis. It is the only agent used for mono therapy prophylaxis against TB

Question 9

Grape fruit juice

Answer 9

Decreased activity of P450 system leading to toxicities caused by slow metabolism of other p450 drugs

Question 10

Acute alcohol abuse

Answer 10

Inhibits -450 system bc p45- enzymes are saturated by the toxic metabolites of acute ingestion

Question 11

Erythromycin (macrolide)

Answer 11

Antibiotic that is commonly used tor bordetalla pertusis, legionella pneumophilia and mycoplasma pneumoniae. It inhibits protein synthesis by binding to the 23s RNA of the 50s ribosomal subunit, thereby blocking translocation

Question 12

Indinavir

Answer 12

HIW protease inhibitor that is used as a component of antiretroviral therapy in HIV AIDS

Question 13

Cimetidine

Answer 13

histamine H2 receptor antagonist that is commonly used in the treatment of heartburn by decreasing stomach acid production

Question 14

Sulfonamides

Answer 14

Have sulfonamide group (sulfa drugs) often interact with p450 system
Common sulfanoamides are antibiotics, diuretics, and dulfonylureas

Question 15

Ketoconazole

Answer 15

For systemic mycoses. Acts by inhibiting fungal ergol sterol synthesis

Question 16

Amiodarone

Answer 16

Is an antiarrhythmic which is a potent inhibitor of a number of cytochrome p450 enzymes

Question 17

P45 inducer

Answer 17

Drugs that increase the activity of p450 causing drugs that are also metabolized by the p450 system to be metabolized at an increased rate

Question 18

Examples of p450 inducer

Answer 18

Phenytoin, griseofulvin, St. John’s wort, carbamazepine, rifampin, barbiturates, chronic alcohol use

Question 19

Griseofulvin

Answer 19

Orally administered antifungal drug Thor treatment of fungal infections of the skin and nails.

Question 20

With does griseofulvin interfere with

Answer 20

Microtubule function and therefore disrupts mitosis of fungal organisms

Question 21

Phenytoin

Answer 21

Antiepileptic drug
Acts to suppress abnormal brain activities via blockade of sodium channels. Also a class 1B anti-arrhythmic

Question 22

Carbamazepine

Answer 22

Anticonvulsant and mood stabilizing drug. It is commonly used for epilepsy and trigeminal neuralgia

Question 23

Rifampin

Answer 23

Used mainly for the treatment of active mycobacterium tb. It acts by inhibiting the DNA dependent RNA polymerase

Question 24

Barbiturates

Answer 24

Drugs that depress the CNS by increasing the duration of chloride channel opening and thus decreasing neuron firing. they are commonly used for anxiety, seizure, and insomnia

Question 25

Chronic alcohol abuse

Answer 25

Causes the liver to increase transcription of p450 enzymes to metabolize the toxic byproducts of alcohol and induces the p450 system

Question 26

St. John’s wort

Answer 26

Herbal treatment for mild depression

Induced or p450