Normally, I don't take cough medicine. After a week of coughing, finally I caved and took 15mg of dextromethorphan twice yesterday.
I started masturbating before bed, and noticed that my clitoris felt really, really numb. It was very annoying and ended up taking about 30 minutes to achieve orgasm, whereas I'm usually done in a few minutes.
I made a mental note to look up any correlation between low-dose dxm (which is a dissociative anesthetic, especially at high doses, as my friends who've done it at recreational doses are all too well-aware) when I awoke.
It only made sense that if it would numb cilia to inhibit the cough-reflex, it could numb the vulva.
So in an attempt to find a correlation between vulval anesthesia and NMDA receptor antagonists (which dxm and things like ketamine, tramadol, and methadone are), I ran across a fun article:
Analgesic synergism between AP5 (an NMDA receptor ... [Pharmacol Biochem Behav. 1998] - PubMed result
Now first: how in the hell did they set up that experiment? Whose bright idea was it to cervically stimulate rats?
And second: what sort of apparatus would be used? Does this apparatus vibrate, and are there controls?
I digress.
That particular article didn't give me a conclusive determination. I did find a few articles relating NMDA receptor antagonists to a reduction in labor pain, so I assume that yes, the dextromethorphan probably was the culprit in my elongated masturbation session.
Maybe this could be marketed as a way for men to last longer, rather than having to use a topical anesthetic that could potentially reduce the stimulation for their partner? Just take an anti-tussive and have great stamina! Or a loss of erection...hmm...