Common adverse reactions of agomelatine that can be confused with an acute porphyric attack are nausea, diarrhoea, constipation, abdominal pain and vomiting. These side effects may potentially be porphyrinogenic if leading to a decrease in carbohydrate intake. Another common side effect of agomelatine is elevations of liver enzymes (ALAT and ASAT), which in rare cases give hepatocellular damage. Care should therefore be taken if starting treatment with agomelatine in patients with hepatic injury risk factors.

Agomelatine is not an inducer or a mechanism-based inhibitor of CYP enzymes, and is not observed to alter the metabolism of other CYP metabolized drugs. No pharmacokinetic porphyrinogenic effects are suspected.

Naphthalene

Agomelatine is a melatonin receptor agonist and a serotonin receptor antagonist which is used in the treatment of major depressive episodes in adults. It is administered orally.

Agomelatine is mainly metabolized by CYP1A2 (90 %), but CYP2C9 and CYP2C19 are also involved. The majority of agomelatine is excreted in the urine as metabolites. Agomelatine is not an inducer of CYP450 enzymes (in vivo), and not an inhibitor of CYP1A2 (in vivo) or the other CYP450 enzymes (in vitro) (Carney 2011, SPC).