Complex sentence: It acts as a peripheral antitussive, with no action in the central nervous system and so does not cause side effects such as constipation or respiratory depression which can be produced by opioid antitussives such as codeine and its derivatives.
Split into simpler sentences: It acts as a peripheral antitussive, with no action in the central nervous system. It does not cause side effects such as constipation or respiratory depression which can be produced by opioid antitussives such as codeine and its derivatives.