Codeine in combination with other narcotic analgesics, general anesthetics, phenothiazines, tranquilizers, sedative-hypnotics, or other CNS depressants (including alcohol) has additive depressant effects.
<Codeine, effect, narcotic analgesics>, <Codeine, effect, anesthetics>, <Codeine, effect, phenothiazines>, <Codeine, effect, tranquilizers>, <Codeine, effect, sedative-hypnotics>, <Codeine, effect, CNS depressants>, <Codeine, effect, alcohol>