Oxolamine under brand names Symphocal, Perebron is used in some countries as a cough suppressant for the treatment of pharyngitis, tracheitis, bronchitis, bronchiectasis, pertussis. Oxolamine possesses anti-inflammatory activity, which causes a reduction in the irritation of the nervous receptors of the respiratory tract.

Dropropizine is a cough suppressant. It has peripheral action in non-productive cough. Dropropizine is commercialized in Latin American and African countries.

Dembrexine is a mucolytic agent which reduces the viscosity of respiratory mucus. It improves movement of mucus in small airways. Dembrexine increases secretion of the serous cells in the glands of the nasal, tracheal and bronchial cells and in type II alveolar cells. It also possesses an anti-tussive effect. Dembrexine is used in the treatment of respiratory disease in horses. All respiratory infections with increased secretions. Acute, sub-acute bronchitis. Chronic respiratory disease. Infection of the upper airways.

Erdosteine is an antioxidant compound developed by Edmond Pharma and approved in Europe for the treatment of chronic bronchitis and COPD. Erdosteine has two thiol groups and is believed to act as a free radicals scavenger (through the formation of the active metabolite I, N-thiodiglycolylhomocysteine). Also the drug effect may be due to the inhibition of the activity of elastase enzyme and its interaction with mucosa. The drug got Orphan Drug designation by FDA for the treatment of bronchiectasis.

Bibenzonium is an antitussive agent. Bibenzonium bromide is a cough suppressant which is stated to have a central action.