Assessment of sexual behaviour and fertility indices in male rabbits following chronic codeine use

Abstract

Background: Codeine is the latest trend of drug abuse, particularly in Nigeria and regarded as the gateway to the abuse of other substances. Objectives: The present study examined the effects of graded doses of codeine on sexual behaviour and fertility profile. Materials and methods: Rabbits were either administered normal saline (0.2 mL), 4mg/kg b.w of codeine (low dose), or 10mg/kg b.w of codeine (high dose) p.o for 6 weeks. Results and discussion: Findings of the study showed that codeine administration significantly increased libido as witnessed by significantly short mount latency (ML), intromission latency (IL), post-ejaculatory interval (PEI) and significantly increased mount frequency (MF), intromission frequency (IF) and ejaculation latency (EL). Furthermore, codeine caused a marked rise in penile reflexes evident by a significant increase in erections, quick flips, long flips and total penile reflexes. However, copulatory efficiency and fertility index were significantly lower in codeine-treated groups when compared with the control. Serum levels of testosterone were also significantly lower in the treated groups. Conclusions: The present study demonstrates that codeine-induced enhancement of sexual performance is via a testosterone-independent mechanism. It also reveals that although codeine enhances copulatory locomotor activity, it is a potential risk factor for infertility.