Respiratory: Cystic Fibrosis

Question 1

Patients with cystic fibrosis who have evidence of lung disease should be offered a mucolytic.
What is the first choice mucolytic?

Answer 1

Dornase alfa: a genetically engineered version of a naturally occuring human enzyme which cleaves extracellular DNA.

Question 2

What is the second choice mucolytic in CF?

Answer 2

Mannitol dry powder for inhalation is recommended.

Mannitol is an osmotic diuretic.

Question 3

Most common respiratory infective agents in CF:

Answer 3

1. S.aureus
2. P. aeruginosa
3. Burkholderia cepacia complex
4. H. Influenzae
5. Non-tuberculosis mycobacteria
6. Aspergillus fumigatus

Question 4

What diuretic is used in cystic fibrosis?

Answer 4

Mannitol dry powder for inhalation is recommended as a second choice mucolytic in CF.

After Dornase alfa.

Question 5

In CF, if eradication therapy of P.aeruginosa is not successfull, sustained treatment with an inhaled antibacterial should be offered.

What is the first-line treatment?

Answer 5

Nebulised colstitmethate sodium.

Brand: Colomycin

Polymyxin antibiotic.

Should not be used in Myasthenia Gravis.

Major adverse effects are dose-related neurotoxicity and nephrotoxicity.

Other inhaled drugs should be adminisitered before colomycin.

Question 6

In those receiving sustained inhaled colomycin in CF but are still deteriorating, what other antibacterials should be considered for use?

Answer 6

Nebulised aztreonam

Nebulised tobramycin or tobramycin dry powder for inhalation.

Question 7

In CF, long-term treatment with which macrolide, at an immunomodulatory dose, should be offered to patients with deterioating lung function or repeated pulmonary exacerbations?

Answer 7

Azithromycin (unlicensed).

In patients who continue to deteriotate despite treatment with azithromycin long term should have the azith stopped and the use of an oral corticosteroid considered.

Question 8

Exocrine pancreatic insufficiency can occur with CF patients, what should be offered to these patients?

Answer 8

Pancreatin:
Creon/pancrex etc.

Dose should be adjusted as needed to minimise any symptoms or signs of malabsorption and an acid-suppressing drug, such as an H2 receptor antagonist or PPI offered if needed.

Question 9

In CF patients who have liver function blood test results which are abnormal, what drug can be given until liver function is restored?

Answer 9

Ursodeoxycholic acid.

Question 10

Patients with CF should be monitored for what other co-morbid conditions? (2)

Answer 10

1. Low bone mineral density

2. CF-related diabetes.