Exam 3 from his study guide

Question 1

Amiodarone LD

Answer 1

1.2-1.8 g/d divided doses up to 10 grams

Question 2

Amiodarone MD

Answer 2

200-400 mg/d

Question 3

Amiodarone + Warfarin

Answer 3

Decrease dose by 25%

Question 4

Amiodarone + Dig

Answer 4

Decrease dose by 50%

Question 5

Amiodarone + HMG-CoA reductase inhibitors

Answer 5

Interactions

Question 6

Amiodarone + Phenytoin

Answer 6

Increase Phenytoin 50%

Question 7

Grapefruit juice may increase oral absorption

Answer 7

Separate 2 hours

Question 8

Drugs that cause QT prolongation

Answer 8

Azoles
Macrolides
FQ
Haloperidol

Question 9

Drugs that delay AV nodal conduction

Answer 9

Non-DHP CCB
BB
Dig

Question 10

Amiodarone Absorption

Answer 10

Very slow and incomplete orally (50-70%)
Food increases rate and extent
Has enterohepatic circulation

Question 11

Amiodarone Distribution

Answer 11

Mainly lipophilic tissues
Tissue concentration 10-400x higher than serum concentration levels
Uses 2 compartment model

Question 12

Amiodarone Metabolism

Answer 12

Major site: Liver 3A4
Minor sites: 1A2, 2C19, 2D6
Active metabolite: desmethylamiodarone

Question 13

Amiodarone is a major inhibitor of these enzymes

Answer 13

3A4
2D6
2C9
P-gp in the gut

Question 14

Amiodarone excretion/elimination

Answer 14

Major route: biliary
Half-life - dependent on time taking amiodarone
-Chronic dosing = 53 day half-life
IV therapy = variable (9-36 days)

Question 15

Factors that change amiodarone elimination

Answer 15

Cirrhosis

Elderly

Question 16

Digoxin oral LD

Answer 16

1-1.5 mg

Question 17

Digoxin IV LD

Answer 17

0.5-1 mg

Question 18

Digoxin MD

Answer 18

0.125-1.5 mg QD

Question 19

Conversion of aminophylline and theophyllin doses

Answer 19

S = 1 for theophylline
S = 0.8 for aminophylline

Question 20

Risk of subtherapeutic busulfan concentrations

Answer 20

Not getting rid of bone marrow that has diseased cells

Question 21

Risk of supratherapeutic busulfan concentrations

Answer 21

Sinusoidal obstruction syndrome (aka veno-occlusive disease [VOD])

• Primary injury to liver
• Significant post-transplant complication leading to mortality