Cystic Fibrosis

Question 1

Ivacaftor (Kalydeco)

Answer 1

pats >/= 4 months
>/= 1 ivacaftor responsive mutation

Question 2

Lumacaftor + Ivacaftor (Orkambi)

Answer 2

pats >/= 2 years
2 copies of F508del

Question 3

Tezacaftor + Ivacaftor (Symdeko)

Answer 3

pats >/= 6 years
2 copies of F508del
-OR-
1 copy + 1 other responsive mutation

Question 4

Elexacaftor + Tezacaftor + Ivacaftor (Trikafta)

Answer 4

pats >/= 6 years
>/= 1 copy of F508del

Question 5

CFTR Modulators DDI:
CYP3A inhibition

Answer 5

Drugs:
- erythromycin
- fluconazole
- clarithromycin
- Itraconazole

Effect:
- increased serum concentration

Fix:
- reduce dosing frq

Question 6

CFTR Modulators DDI:
CYP3A Induction

Answer 6

Drugs:
- Rifampin
- Carbamazepine
- Phenobarbital
- Phenytoin
- St John’s Wort

Effect:
- decreased serum concentration

Fix:
- avoid concomitant use

Question 7

Mucolytics / Hydrating Agents / Bronchodilators

Answer 7

• dornase alfa
• hypertonic saline
• azithromycin
• inh tobramycin
• inh aztreonam

Question 8

Azithromycin dosing by weight

Answer 8

< 25kg: 10mg/kg MWF
25-40kg: 250mg MWF
>40kg: 500mg MWF

Question 9

Inhaled tobramycin and aztreonam dosing schedule

Answer 9

28 days on and 28 days off

Question 10

PERT dosing

Answer 10

Infants: 2000-5000 U per 120mL formula

</=4 years: 1000U/kg with meals and 1/2 with snacks

> 4years: 400-500U/kg with meals and 1/2 with snacks

Question 11

ADEK vitamin dosing

Answer 11

<12mo: 1mL PO QD
1-3yrs: 2mL PO QD
4-10yrs: 1 tab PO QD
>10 yrs: 2 tab PO QD

Question 12

Vitamin D3 initial dosing

Answer 12

1-11yrs : 1,000 IU QD
>11yrs: 2000 IU QD

Continue for 3 months and reassess

Question 13

Vitamin D3 dosing: It has been 3 months and vitamin D levels are still <30ng/mL
New dosing?

Answer 13

</= 5yrs: 50,000 IU MWF x 1 month
> 5yrs: 50,000 IU QD x 1 month

Question 14

Vitamin K dosing

Answer 14

(during IV antibiotics)

5 mg PO BID

Question 15

Acute Exacerbation:
What treatments should be increased?

Answer 15

• vest therapy
• dornase alfa
• hypertonic saline
• bronchodilators

Question 16

Acute Exacerbation:
Duration of antibiotic treatment

Answer 16

14-21 days

Question 17

Acute Exacerbation:
(+) h/o MSSA
(-) PA

Answer 17

Anti-staphylococcus penicillin
-OR-
Cephalosporin

Question 18

Acute Exacerbation:
(+) h/o MSSA
(+) PA

Answer 18

Cefepime + Aminoglycoside

Question 19

Acute Exacerbation:
(+) h/o MRSA
(-) PA

Answer 19

Vancomycin
-OR-
Linezolid

Question 20

Acute Exacerbation:
(+) h/o MRSA
(+) PA

Answer 20

Vancomycin or Linezolid
+
Aminoglycoside
+
Ceftazidime

Question 21

Aminoglycoside monitoring

Answer 21

Peak: 22.5-27.5 mcg/mL
Trough: < 0.1 mcg/mL

Question 22

Vancomycin monitoring

Answer 22

Trough: 10-20 mcg/mL
AUC/MIC >/= 40