Abstract

Drugs in the Selective Serotonin Recaptation Inhibitors (SSRI) class have activity in the central nervous system on neuronal serotonin receptors, selectively potentiating the inhibition of the receptor pump of this neurotransmitter. However, they can act in a pharmacological remodulation process with antibacterial and antifungal properties. Considering the pathogenicity of E. coli and S. aureus bacteria and Candida genus fungi and, taking into account their resistance profiles to usual drugs, the present study aimed to analyze the antimicrobial and antimycotic activity of five SSRI drugs commercially available (Citalopram 20 mg, Oxalate of Escitalopram 10 mg, Fluoxetina Hydrochloride 20 mg, Paroxetine Hydrochloride 10 mg, Sertraline Hydrochloride 50 mg) front to ATTCs strains of the aforementioned bacteria and isolates clinical studies with Candida albicans and Candida non-albicans. Two adapted methodologies were used, in which the drugs were tested at different concentrations against inoculums of E. coli, S. aureus, C. albicans, C. glabrata, C. tropicalis, C. parapsilosis and C. Kruse., incubated at 35ºC (± 2ºC) until 48h. Test validation was determined by the growth of positive controls (pure inocula), which were submitted to the same procedures as the inocula containing the drugs. Inhibition of fungal and bacterial growth of all drugs was observed, with a variable concentration-dependent pattern. Fungal organisms were more sensitive and E. coli proved to be the most resistant organism. The results achieved were satisfactory with regard to the remodulation of SSRIs as anti-infective agents against the tested microorganisms. Among the five drugs evaluated, citalopram and escitalopram were the ones with the lowest inhibitory activity. It should be noted that their chemical structures are quite similar, being escitalopram, the S-enantiomer of citalopram (mirror structure). Considering that the amount of citalopram active compound was more than twofold the amount of escitalopram active ingredient, it is understood that citalopram inhibited the growth of more species and with lower MICs. The inhibitory activity of the drugs tested against the fungal isolates obtained a very satisfactory result, being fluoxetine, paroxetine and sertraline able to inhibit all fungal species at all concentration evaluated.