Vaginal pain during intercourse (“dyspareunia”) is not uncommon among breast cancer survivors who are taking medications to block or lower estrogen. This is believed to be due to the thinning of the vaginal tissues when estrogen levels are low.
A recent study found that the topical application of lidocaine (4% liquid lidocaine solution) to the vulvar vestibule for 3 minutes before vaginal penetration significantly reduced pain.
The study was a double-blind trial of 46 breast cancer survivors with dyspareunia. The women were randomized to the precoital application of 4% aqueous (also known as “liquid”) lidocaine or saline for 4 weeks. They recorded pain associated with intercourse and twice-weekly tampon insertion in a diary. The blinded trial was followed by a 2-month period of time during which all patients were allowed to use the liquid lidocaine.
- After the open-label trial, 90% of women reported comfortable penetration.
- After the 4-week double-blind phase, median score on a 10-point pain scale was lower in the lidocaine group than in the placebo group (1.0 vs 5.3; P = .015).
- After the 2-month open-label phase, pain scores remained at 0 or 1.
- At the beginning of the study, 20 women had chosen to abstain from sex. At the end of the open-label trial, 85% of these women had resumed penetrative intimacy.
- None of the partners complained of penile numbness.