leukotriene modifiers, methylxanthines, and anti-IgE

Question 1

montelukast brand

Answer 1

singulair

Question 2

montelukast (singulair) dosage form

Answer 2

tablets (chewable) - 4mg, 5mg, and 10mg
granule packets - 4mg

Question 3

zafirlukast brand

Answer 3

accolate

Question 4

zafirlukast (accolate) dosage form

Answer 4

10 or 20 mg

Question 5

zileuton brand

Answer 5

zyflo CR

Question 6

zileuton (zyflo cr) dosage forms

Answer 6

IR tablets - 600 mg
ER tablets - 600 mg

Question 7

leukotriene modifiers

Answer 7

block the production of leukotrienes
montelukast (singulair)
zafirlukast (accolate)
zileuton (zyflo)

Question 8

montelukast (singulair) dosing in 0-4 yos

Answer 8

approved for 1 to 5 yos
4 mg qhs

Question 9

montelukast (singulair) dosing in 5-11 yos

Answer 9

approved for 6 to 14 yos
5mg qhs

Question 10

zafirlukast (accolate) dosing in 5-11 yos

Answer 10

10 mg bid

Question 11

montelukast (singulair) dosing in adults

Answer 11

10mg qhs

Question 12

zafirlukast (accolate) dosing in adults

Answer 12

20 mg bid

Question 13

zileuton (zyflo cr) dosing in adults

Answer 13

IR - 600 mg qid
ER - 1200 mg bid

Question 14

adverse effects of leukotriene modifiers

Answer 14

neuropsychiatric events (agitation, anxiety, abnormal dreams, hallucinations, depression, suicidal thinking)
churg-strauss syndrome (rare)
increases transaminases (specifically zafirlukast and zileuton)

Question 15

clinical pearls of leukotriene modifiers

Answer 15

less effective than low dose ICS and ICS/LABA combos in asthma
have not been adequately trialed in COPD

Question 16

montelukast (singulair) clinical pearls

Answer 16

minor substrate of CYP2C8/9 and 3A4
not for acute relief of symptoms
boxed warning for neuropsychiatric events

Question 17

zafirlukast (accolate) clinical pearls

Answer 17

take at least 1 hour before or 2 hours after meals
can increase INR
major substrate, minor inhibitor of CYP 2C9

Question 18

zileuton (zyflo cr) clinical pearls

Answer 18

weak cyp1A2 inhibitor
take with food

Question 19

methylxanthines

Answer 19

bronchodilation through inhibition of PDE 2 and 4
theophylline (theochron)

Question 20

theophylline brand

Answer 20

theochron

Question 21

theophylline (theochron) dosage form

Answer 21

ER 12H tabs - 100, 200, 300, 400, and 450 mg
ER 24H tabs - 400 and 600 mg
ER 24H Caps - 100, 200, 300, and 400 mg
Liquid - 80mg/15mL

Question 22

theophylline (theochron) acute exacerbation dosing in adults

Answer 22

loading dose typically given IV as aminophylline
followed by maintenance IV infusion

Question 23

theophylline (theochron) chronic management dosing in adults

Answer 23

smokers - 16mg/kg/day divided
nonsmokers - 13mg/kg/day divided

Question 24

theophylline (theochron) dosing in adults

Answer 24

doses based on serum concentrations and treatment of acute exacerbations or chronic management
target range 5-15mcg/mL
toxic is greater than 20 mcg/mL

Question 25

adverse effects of theophylline (theochron)

Answer 25

insomnia gastrointestinal upset hyperactivity hypotension (PDE 3 inhibition) tremor

Question 26

dose related toxicity of theophylline (theochron)

Answer 26

tachycardia (PDE 3 inhibition) nausea (PDE 3 inhibition) vomiting headache seizures arrhythmias

Question 27

contraindications of theophylline (theochron)

Answer 27

peptic ulcer disease arrhythmias seizure disorders

Question 28

drug interactions of theophylline (theochron)

Answer 28

major substrate of cyp3a4, 1a2, and 2e1 increase concentration - cimetidine, erythromycin, clarithromycin, ciprofloxacin, ticlopidine decrease concentration - phenobarbital, phenytoin, carbamazepine, rifampin (and smoking)

Question 29

anti-IgE drugs

Answer 29

inhibit IgE binding to receptors on mast cells and basophils inhibit mediator release and attenuation of early and late phase allergic response omalizumab (xolair)

Question 30

omalizumab brand

Answer 30

xolair

Question 31

omalizumab (xolair) dosage forms

Answer 31

150mg/1mL prefilled syringe 75mg/0.5mL prefilled syringe 150mg/1.2mL after reconstitution with 1.4mL of sterile water for injection

Question 32

omalizumab (xolair) dosing in 5-11 yos

Answer 32

approved for over 6 yos 150 to 375 mg sq every 2 to 4 weeks depending on body weight and pretreatment serum IgE levels

Question 33

omalizumab (xolair) dosing in adults

Answer 33

150 to 375 mg sq every 2 to 4 weeks depending on body weight and pretreatment serum IgE levels

Question 34

adverse effects of omalizumab (xolair)

Answer 34

headache injection site reactions arthralgias thrombocytopenia pharyngitis sinusitis upper respiratory tract infections

Question 35

boxed warning for omalizumab (xolair)

Answer 35

anaphylaxis

Question 36

clinical pearls of omalizumab (xolair)

Answer 36

do not give more than 150mg per injection monitor for anaphylaxis before and after injection FDA approved for moderate to severe persistent asthma in patients with a positive skin test or reactivity to a perennial aeroallergen and symptoms that are inadequately controlled with ICS