What are side effects of mixing prozac, (fluoxetine) oxymorphone?

Inhibiting metabolic: Activity of both since both are actively metabolized by cytochrome p450. Functionally it's not clear if that would augment the effectiveness of either of the medications but the adverse reactions and serious depression of respiratory function of the opioid Oxymorphone could have fatal consequences.

No interaction: There is no contraindication to use of both.