<p>Citalopram is bicyclic phthalane derivative and a selective serotonin re-uptake inhibitor, with little or no effect on noradrenaline, dopamine and GABA re-uptake. The inhibitory activity explains the antidepressant property of citalopram. It has no or very low affinity for 5-HT1AA, 5-HT2A, D1&nbsp;and D2&nbsp;receptors, &alpha;1, &alpha;2, &beta;-adrenergic, histamine H1, muscarinic, cholinergic, benzodiazepine and opioid receptors.</p>