Drug points: Increased female sexual response after oxytocin

A 26 year old woman presented 17 months after the birth of her second child for some temporary help with the breast feeding of her nephew. The breast feeding of her child had been intermittent after 6-8 months and ceased at 15 months. Lactogenesis had continued with minimal milk expressed. A 28-32 day menstrual cycle had returned by 12 months post partum. A progestogen only pill (levonorgestrel 30 μg) had been used since 15 months.

A synthetic oxytocin spray (Syntocinon; Sandoz) was used on day 17 of her irregular cycle. Let down of milk occurred but left the infant unsatisfied. No further attempts were made to breast feed. About 2 hours after the use of two activations (8 IU) of oxytocin, she noticed copious vaginal transudate trickling down her leg. Intense sexual desire had followed, and she reported that her cervix had opened slightly. She had initiated sex with her partner and commented that the uterine and vaginal contractions were intensified at orgasm, along with heightened subjective pleasure.

Oxytocin was repeated on day 19 with similar effects lasting again for three hours after their onset. Seven to 10 days later she ceased taking levonorgestrel and restarted barrier contraception. Two weeks later she readministered the spray but no sexual responses occurred.

In a detailed sexual history she revealed that she had been sexually active during her second pregnancy with orgasm about three times a week. Most sexual activity ceased for the months after ceasarean section and then resumed as before. She also described feelings of mild arousal with breast feeding her children, an experience common among other women.

To our knowledge, no similar cases have been reported,1 although reviews of animal studies indicate that interactions between sex steroids and oxytocin have been documented in mammals.*RF 2-4* Contextual issues surrounding other prosexual substances and oxytocin as potential aphrodisiacs for women have been discussed.5