A Preliminary Approach to Oral Low-Dose Ketamine Self-Administration in Mice (Mus musculus)

With ketamine gaining attention as a therapeutic drug, oral administration offers an effective alternative to traditional parenteral routes. However, a significant gap remains in understanding its use via voluntary ingestion. This preliminary study aimed to explore the feasibility of oral ketamine self-administration in mice (Mus musculus), while investigating the effects of low concentrations on the brain, liver, and kidney. Adult mice were divided into three groups and received ketamine in their drinking water for 16 days at 0 (control), 5 (K5), or 10 mg/L (K10). A transient decrease in water consumption was observed in both sexes in the K10 group; however, only females in this group showed differences in ketamine intake between groups on some days. Oxidative stress markers measured in the brain, liver, and kidney only revealed higher catalase activity in the brains of females. No significant alterations were observed in liver and kidney function in either sex, nor in inflammation, apoptosis, or DNA damage in kidney tissues. Overall, these findings support the viability of voluntary oral ketamine administration and accentuate the need to refine the proposed model, not only to prevent water consumption inhibition but also to extend the exposure period, explore potential sex-related differences in ketamine intake, and further confirm the safety of oral ketamine administration.