Reboxetine is not an inhibitor or an inducer of CYP3A4 or CYP1A2 in vivo. Risk for gastrointestinal adverse events in the form of constipation, nausea and vomiting motivates vigilance against insufficient intake of food, especially of carbohydrate.

Reboxetine is a racemic mixture and consist of R,R(-)-reboxetine and S,S(+)-reboxetine. Chiral conversions does not occur in vivo (Fleishaker 2000).

Reboxetine is a noradrenaline reuptake inhibitor and is indicated for the treatment of depression. Very common and common side effects that can be potentially porphyrinogenic through reduction in carbohydrate intake and that also can be confused with an acute porphyria attack are decreased appetite, paresthesia, hypertension, tachycardia, constipation, nausea and vomiting. Other common side effects are headache, dizziness, agitation and anxiety.

In vitro data indicates that reboxetine is metabolised by CYP3A4 (SPC). Identified metabolic pathways are hydroxylation, O-dealkylation and oxidation of the functional groups (Fleishaker 2000). Ketoconazole increased the mean AUC of R,R(-)-reboxetine and S,S(+)-reboxetine mean AUC by 58% and 43%, respectively, when co-administrated (Fleishaker 2000 and Herman 1999). This indicates that reboxetine is a substrate of CYP3A4. Reboxetine was shown to be a weak competitive inhibitor of CYP3A4 and CYP2D6 and to not be inhibitor of CYP1A2, CYP2C9 and CYP2C19 in human microsomal preparations (Spina 2012 and Wienkers 1999). The inhibitory effect on CYP3A4 and CYP2D6 is unlikely to be relevant in vivo because it occurs at concentrations higher than those achieved clinically (Spina 2012). When co-administrated, reboxetine did not have any significant effect on the clearance of alprazolam, a CYP3A4 substrate. This indicates that reboxetine is not an inhibitor or an inducer of CYP3A4 in vivo (Fleishaker 2000). An in vivo study showed that reboxetine did not affect the mean plasma concentrations of clozapine (CYP1A2 substrate) significantly, which indicates that reboxetine is not an inhibitor or an inducer of CYP1A2 (Spina 2001). In vivo studies have also shown that reboxetine does not inhibit or induce CYP2D6 in vivo (Fleishaker 200).