Did Desipramine or Lidocaine Beat Placebo for Vulvar Pain?

Who and what did the trial test?

The 2010 trial randomized 133 women with localized, touch-provoked vulvar pain, eligible ages 18–50, for 12 weeks. It tested oral desipramine, increased toward 150 mg/day, and hospital-compounded 5% lidocaine cream four times daily, separately and together, against matching placebos. Analysis included 132 participants; 112 completed treatment.¹

Did either treatment outperform placebo?

Tampon-test pain fell 33% with double placebo, 24% with desipramine alone, 20% with lidocaine alone and 36% with both. Neither drug reduced pain significantly more than placebo (P=.37 and .21). An interaction between drugs (P=.04) did not establish combination benefit: the testing sequence stopped when individual drugs failed.¹

A resting pulse above 100 beats/minute occurred in 16% taking desipramine versus 2% without it. Missing observations were carried forward. NIH funded the trial; authors reported no conflicts.¹

This result does not establish equivalence or extend to other lidocaine formulations, schedules or pain diagnoses. Confirm the exact product and treatment goal.

What belongs in a prescribing review?

Desipramine’s current US label covers depression; vulvar-pain treatment is off-label. Its boxed warning concerns increased suicidal thoughts and behavior in children, adolescents and young adults. All ages need monitoring, particularly after starting or changing doses. Report sudden mood or behavioral changes promptly.²

The label warns about heart-rhythm problems and interactions, including MAO inhibitors and other serotonergic medicines. Bring your complete medicine list and discuss heart disease, urinary retention, glaucoma, pregnancy and breastfeeding. Do not stop a prescription abruptly: withdrawal symptoms can follow prolonged treatment. Arrange changes with the prescriber.²

The current Encube 5% lidocaine ointment label describes a different product from the trial cream. It warns that excessive amounts or short dosing intervals can cause serious systemic effects, and damaged mucosa can increase absorption. Ask the clinician to specify the product, amount, site and timing; do not transfer the research schedule to a numbing product you own.³

UK NHS⁴ guidance describes examination, sometimes including an infection swab, and specialist care that can involve physiotherapy, nerve-pain medicines or psychological therapy. Persistent pain deserves reassessment even when an examination looks normal.⁴

“When Sex Hurts” in Down There, Decoded asks where pain occurs, what triggers it and how long it lasts. Bring those details and your previous treatment dates to the review. You do not need to repeat a painful tampon test to prepare for it.