Codeine Adverse effects

Common adverse drug reactions associated with the use of codeine include itching, nausea, vomiting, drowsiness, dry mouth, miosis, orthostatic hypotension, urinary retention and constipation.[10]

Tolerance to many of the effects of codeine develops with prolonged use, including therapeutic effects. The rate at which this occurs develops at different rates for different effects, with tolerance to the constipation-inducing effects developing particularly slowly for instance.

A potentially serious adverse drug reaction, as with other opioids, is respiratory depression. This depression is dose-related and is the mechanism for the potentially fatal consequences of overdose.

Another side effect commonly noticed is the lack of sexual drive.[11]

Codeine has also been known to interact negatively with some psychiatric medications such as reboxetine and venlafaxine.[citation needed]

Some people may also have an allergic reaction to codeine, which may cause severe allergic reactions such as the swelling of skin and rashes.