Analgesia additive interaction between tadalafil and morphine in an experimental animal model

Since both morphine and tadalafil have been proven to exert some of their analgesic activity through modulation of the NO–cGMP pathway, the aim of the current study is to evaluate the pharmacologic interaction between tadalafil and morphine to decrease the dose of morphine and subsequently its side effects. The assessment was carried out through isobolographic analysis relative to ED 50 s of both morphine and tadalafil obtained by tail-flick...