Hypertonic Saline for CF

Last updated Jan. 3, 2023, by Teresa Carvalho, MS

✅ Fact-checked by José Lopes, PhD

What is hypertonic saline for Cystic Fibrosis?

Hypertonic saline is an inhaled medication that helps people with cystic fibrosis (CF) hydrate their airways so they can clear mucus more easily.

How does hypertonic saline work?

CF is caused by a mutation in the CFTR gene that provides instructions for making a protein of the same name. The CFTR protein controls the movement of chloride and water into and out of cells. This flow is key for producing mucus that keeps organs protected and lubricated.

In CF, CFTR doesn’t properly regulate the movement of salt and water, leading to thick and sticky mucus being produced. This causes difficulty breathing and raises the risk of lung infections.

Hypertonic saline is a solution of sodium chloride (common salt) at concentrations greater than naturally found in the body. Once inhaled, hypertonic saline helps clear mucus and has been associated with lung function improvements and fewer exacerbations, or sudden symptom worsening.

Who can take hypertonic saline?

Hypertonic saline is recommended to people with CF, ages 6 and older, who have a forced expiratory volume at one second, or FEV1, of 40% or higher (% predicted). FEV1 measures how much air can be exhaled in one second after a deep breath.

Who should not take hypertonic saline?

Hypertonic saline should not be used by people who have had allergic reactions to the medication.

How is hypertonic saline administered?

Hypertonic saline is a clear, colorless solution that’s inhaled through a nebulizer, which transforms liquid medication into an aerosol. The medication is usually given twice a day.

As the solution is sterile, patients should wash their hands before using it. The medication is available in different concentrations that reflect the amount of sodium:

  • 3%
  • 3.5%
  • 7%

Patients should place the contents of a single vial into a clean nebulizer cup. The mouthpiece of the nebulizer should be held on top of the tongue, between the teeth. Patients should breathe through the mouth and take a few deep breaths every minute or two to make sure the medication reaches the smaller airways.

Hypertonic saline should be inhaled until it is totally used. When a sound like spitting is heard, it means the medication is almost used up.

If patients need to cough or stop the medication, the compressor should be turned off. It should be turned on to resume treatment.

The medication should be administered in a well-ventilated area away from electronics as it can damage electrical equipment.

The treatment should be stored at room temperature. Excessive heat and freezing should be avoided.

Hypertonic saline in clinical trials

PRESIS trial

PRESIS (NCT01619657) was a Phase 2 trial that included 42 newborns and infants up to 4 months of age. Patients inhaled either hypertonic saline (6% sodium chloride) or isotonic saline (0.9% sodium chloride; the same concentration found in body fluids), twice daily over a year.

Lung function was assessed by the lung clearance index that measures how long it takes for a tracer gas to be cleared from the lungs while lung structure was evaluated through a chest MRI.

Results showed babies who inhaled hypertonic saline had a greater change in lung clearance index, suggesting improved airflow in the lungs, in contrast to those treated with isotonic saline.

The study also found that babies treated with hypertonic saline had significant weight gain and growth.

SHIP and SHIP-CT studies

The Saline Hypertonic in Preschoolers (SHIP) (NCT02378467) as well as the SHIP-CT study (N02950883) tested 7% hypertonic saline versus 0.9% isotonic saline in preschool children with CF. In both trials, the medication was given twice daily for 48 weeks.

Results of the SHIP trial showed treatment with hypertonic saline improved lung function.

In the SHIP-CT study, children had chest CT scans to obtain images of the lungs at the beginning and end of treatment. Results showed a high number of patients had moderate to severe changes in lung structure that were more evident in the isotonic saline group. The study also found that lung damage was significantly less likely in children given hypertonic saline. These children had a 0.67% less damaged lung volume at the end of treatment.

Other trials

A review study of 17 clinical trials (including SHIP-CT) assessed hypertonic saline as a therapy for CF. A total of 966 patients were included, from 4 months to 63 years of age.

Results from three trials indicated improvement in lung function at four weeks in patients older than 12. However, this improvement was not sustained at later timepoints according to data from one trial.

Hypertonic saline also reduced the frequency of pulmonary exacerbations — episodes of a sudden worsening of respiratory symptoms — in patients over age 6, and may improve quality of life.

Common side effects of hypertonic saline

After taking hypertonic saline, patients may experience the following side effects:

  • cough
  • chest tightness
  • sore throat
  • difficulty breathing
  • swelling in hands or feet
  • tiredness
  • confusion
  • irregular heart beat
  • extreme thirst
  • increased or decreased urination
  • leg discomfort
  • muscle weakness

Allergic reactions

 The use of hypertonic saline may cause allergic reactions. Patients should inform their healthcare team if signs of an allergic reaction occur (such as swelling, chest pain, and a light-headed feeling.)

Use of other medications

Patients are recommended to tell their healthcare provider about medications they take that may interfere with hypertonic saline, particularly potassium supplements, diuretics, steroids, treatments for high blood pressure, or those containing sodium.

Use in pregnancy and breastfeeding

It is still unknown if sodium chloride inhalation can cause harm to a developing fetus or if it can pass to breast milk. Patients who are using this treatment are recommended to talk with their healthcare team if they are pregnant, plan to be pregnant, breastfeeding or plan to do so.


Cystic Fibrosis News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.

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