abx

Question 1

why can all antibiotics potentiate the effects of warfarin

Answer 1

• abx inhibit intestinal flora that produce vitamin K

Question 2

metabolism of warfarin in via

Answer 2

• hepatic CYP450

Question 3

Which abx should be avoided in patients taking warfarin

Answer 3

• ciprofloxacin
• macrolides
• metronidazole
• bactrim

Question 4

patients who are taking fluoroquinolones should stop taking products that contain because together, they form insoluble complexes in the gut

Answer 4

• cations :
  
  • calcium
  • magnesium
  • aluminum
  • ferrous sulfate

Question 5

if patients on fluoroquinolones are unable to stop taking divalent and trivalent cations, how should they take these medications

Answer 5

• take them at least 2-4 hours apart

Question 6

antiepileptics such as phenytoin, carbamazapine, and phenobarbitol are commonly metabolized by the

Answer 6

• liver

Question 7

effects of antiepileptics are potentiated by inhibitors of cytochrome P450 such as

Answer 7

• macrolides *
• fluco/keto/itraconazole

Question 8

which macrolide does NOT inhibt P450

Answer 8

azithromycin

Question 9

education for patient on birth control to whom you prescribe an abx

Answer 9

• encouraged to consider using an alternative method of contraception for the duration of the abx cycle

Question 10

sildenafil (viagra) is primarly metabolized in

Answer 10

• liver by cytochrome P450 3A4

Question 11

patients who are taking a cytochrome P450 inhibitor should have what adjustment to their dose of sildenafil (viagra)

Answer 11

• initiate sildenafil (viagra) therapy in the lowest dosage possible

Question 12

toxic effects of HMG Co-A reducatase inhibitors (statin)

Answer 12

• elevated serum transaminase levels
• myopathy
• rhabdomyolysis
• acute renal failure

Question 13

risk of toxicity of statins is increased when statins are coadministered with what medications

Answer 13

• erythromycin
• itraconazole
• niacin
• gemfibrozil