IV-NAC effective against respiratory disease with abnormal mucus secretion

The study, featured in European Review for Medical and Pharmacological Sciences, provides new evidence for administering IV NAC in this indication in clinical situations where the preferred route is intravenous.

N-acetylcysteine was introduced in the 1960s and is well-established as a mucolytic agent for respiratory conditions (acute and chronic). In various European countries, NAC is licensed in this indication and is available in inhaled, parenteral, and oral formulations. Based on many years of use in clinical practice, NAC has shown an excellent tolerability and safety profile.

In certain circumstances, IV administration of NAC may be preferred as a mucolytic for respiratory conditions, e.g. severely ill hospitalized patients. Considering the lack of clinical trials evaluating the safety and efficacy of IV NAC as a mucolytic, the authors state, "It is vital to establish IV NAC's efficacy as an expectorant and mucolytic in a large, robust clinical trial.

Against the above background, W. Tang, Shanghai Jiao Tong University School of Medicine, Shanghai, China, and colleagues aimed to evaluate whether IV NAC is superior to placebo and non-inferior to ambroxol in improving expectoration difficulty and sputum viscosity by conducting a large, randomized, multicenter, controlled, subject, and rater-blinded study.

The study included 333 hospitalized subjects from 28 centres in China with respiratory diseases (such as chronic bronchitis and exacerbations, acute bronchitis, bronchiectasis, mucoviscidosis, and emphysema) and abnormal mucus secretion. They were randomly allocated in the 1:1:1 ratio to receive NAC 600 mg, ambroxol hydrochloride 30 mg, or placebo as an IV infusion twice daily for seven days. Expectorant and mucolytic efficacy was evaluated by ordinal categorical 4-point scales and examined by stratified and modified Mann-Whitney U statistics.

The study led to the following findings:

• NAC showed consistent and statistically significant superiority to placebo and non-inferiority to ambroxol in change from baseline to day 7 in sputum viscosity scores [mean difference 0.24 versus placebo] and expectoration difficulty score [mean difference 0.29 versus placebo].
• Safety findings confirm the good tolerability profile of IV NAC reported from previous small studies, and no new safety concerns were identified.

"This multicenter randomized study found that IV NAC 600 mg BID was significantly superior to placebo and non-inferior to IV ambroxol 30 mg BID in improving sputum viscosity and expectoration difficulty following seven days of treatment," the researchers wrote.

"It provides new evidence for administering IV NAC in respiratory diseases with abnormal mucus secretion in clinical situations where the IV route is preferred", they concluded.

Reference:

Tang, W, et al. "Intravenous N-acetylcysteine in Respiratory Disease With Abnormal Mucus Secretion." European Review for Medical and Pharmacological Sciences, vol. 27, no. 11, 2023, pp. 5119-5127.