36 patients with interstitial lung disease will be randomized to 1 weeks treatment with morphine hydrochloride as oral linctus 5 mg, four times a day, and 5 mg as needed up to 4 times a day, or corresponding doses of placebo.

VAS score for dyspnea will be evaluated after 1 hour and 1 week at follow up. Other questionnaires will also be evaluated (GAD-7, K-BUILD, Leicester score)

Inclusion Criteria:

• A diagnosis of interstitial lung disease (IPF, NSIP, RA-ILS, Scl-ILS, MCTD-ILS, asbestous, drug induced ILD, unclassified ILD)
• Dyspnea corresponding to Medial Research Councils (MRC) dyspnea score ≥ 3
• Written consent
• Age ≥ 18 years
• Competent
• For fertile women: Negative pregnancy test
• For fertile and sexually active participants: Use of safe anti-conceptionals

Exclusion Criteria:

• Ongoing infection
• Decreased lung function to a degree which makes any form of respiratory depression life threatening
• Treatment with morphine or morphine analogues
• Allergy towards morphine hydrochloride