Cystic Fibrosis

Question 1

A mutation in what gene causes cystic fibrosis? What does it cause

Answer 1

cystic fibrosis transmembrane conductance regulator (CFTR)

Causes abnormal transport of chloride, bicarbonate and sodium ions causing thick secretions

Question 2

What organs does CF affect?

Answer 2

Pancreas, lungs, liver, intestines

Question 3

Patients with CF have (high/low) levels of sodium in their sweat

Answer 3

High

Question 4

Classic s/sx of CF

Answer 4

Salty tasting skin
Poor growth
Poor weight gain
Coughing and SOB
Statorrhea (fatty stools)
Malnutrition

Question 5

In what order should inhaled medications be given for CF??

Answer 5

1) Inhaled bronchodilators (albuterol) - opens airways
2) Hypertonic saline (HyperSal) - mobilizes mucus to improve airway clearance
3) Dornase alfa (Pulmozyme) - decreases viscosity of mucus
4) Chest physiotherapy - mobilizes mucus to improve airway clearance
5) inhaled antibiotics

Question 6

Most common organism in CF infections

Answer 6

Staph and H. influ most common

Pseudomonas also

Question 7

Doses in CF patients tend to be (larger/smaller) - why?

Answer 7

Larger

Altered PK

Question 8

Dosing schedule for inhaled antibiotics for CF lung infection

Answer 8

28 days on, 28 days off

Question 9

Dornase alfa (Pulmozyme) MOA, notes

Answer 9

Degrades extracellular DNA in lungs to decrease viscosity of mucus
Store ampules in refrigerator
Protect from light

Question 10

What antibiotics are used to target pseudomonas in CF?

Answer 10

All are inhaled

Tobramycin (TOPI), Aztreonam, Azactam

Question 11

Inhaled tobramycin SE, notes

Answer 11

SE: ototoxicity, tinnitus, voice alteration, mouth and throat pain
Notes: 28 days on, 28 days off, dosed q12h but must be at least 6 hours apart

Question 12

Inhaled Aztreonam and Azactam SE and notes

Answer 12

SE: allergic reactions, bronchospasm, fever, wheezing, cough, chest discomfort
Notes: 28 days on, 28 days off, refrigeration recommended

Question 13

Azithromycin indication in pseudomonal CF infections

Answer 13

decreases inflammation and decreases exacerbations

Dosed three times weekly

Question 14

Why do CF patients need to supplement pancreatic enzyme products? What medication is used?

Answer 14

To help break down fat, starches, and protein

Pancrealipase (Creon, Viokace, Zenpep)

Question 15

Pancrealipase (Creon, Viokace, Zenpep) warnings, SE, max dose, when to take

Answer 15

Warnings: colonic strictures, mucosal irritation
SE: abdominal pain, flatulence, nausea
Max 2500 units/kg/meal or 10,000 units/kg/day
Take before or with all meals or snacks

Question 16

What must Viokace be administered with?

Answer 16

PPI

Question 17

What medications are cystic fibrosis transmembrane conductance regulator (CFTR) modulators?

Answer 17

Ivacaftor (Kalydeco)
Lumacaftor/ivacaftor (Orkambi)
Tezacaftor/ivacaftor (Symdeko)
Elexacaftor/tezacaftor/ivacaftor (Trikafta)

Question 18

Ivacaftor (Kalydeco) MOA, approved mutation

Answer 18

MOA: increases time CFTR channels remain open, enhancing chloride transport activity
Approved mutation: HETEROZYGOUS F508del mutation
Take with high fat food

Question 19

Lumacaftor/ivacaftor (Orkambi)
Tezacaftor/ivacaftor (Symdeko)
Elexacaftor/tezacaftor/ivacaftor (Trikafta) MOA and approved mutation

Answer 19

Increases amount of CFTR delivered to the cell surface
Approved mutation: HOMOZYGOUS F508del mutation
Take with high fat food