Particularly disturbing was waking up again about a half-second before the crash with the tree approaching me at speed.
What happened? Narcolepsy. Why? Well, it appears that I have untreated sleep apnea, and narcolepsy is one of the side of effects of having untreated apnea. Amazingly enough, there is a medication to treat it (which, in hindsight, since I'm finishing this up in 2023) which works very well. The bad news is that it is extremely expensive, so if insurance covers it at all, it is usually with an enormous co-pay (on the order of $50/month, and if you don't, it can cost between $750 and $1300/month. (That was then, and surprisingly, that hasn't changed in all the intervening time: The French company that owns the patents agreed to make generics, but only if they owned the generic-making company, with a promise to release that to other companies in time...which they've done, but that didn't significantly change the price, either.)
What treats narcolepsy?
Modafinil was the original medicine in this particular family. The odd fact is that it isn't very pure, for that same reason that not all racemic molecule can't be trusted to stay the same.
Racemic??
Racemic molecules are chiral, meaning that they have "handedness". If you have the left-handed and right-handed versions, (and are either microscopic yourself or have really good microscopes), you can't turn one so that it is identical to the other, even though they use exactly the same atoms and, other than the handedness, the exact same structure. Probably the most famous racemic drug was Thalidomide, the drug which was, at one time, considered "God's gift to Pregnant women", and then, as the cause of horrific birth defects. Thalidomide consists of two structural units with a single bond between them, one unit being a 'glutarimide ring' and the other a phthalimide. The phthalimide portion is a dual-cycle structure, a five-sided carbon ring mated at one side with a six-sided carbon ring, with the extreme point of the five sided ring having a nitrogen atom substituted for the carbon. On each of the the two neighboring carbon atom, an oxygen atom is held in a double-bond. The glutarimide ring is a six-sided carbon ring, which, similarly, has a substituted nitrogen atom with two double-bonded oxygen atoms on either side, but the nitrogen is not at the extreme from the bond between the two constituent units. It is offset from that point so that one of the oxygen atoms is at the extreme end. The bond between the two units goes from the nitrogen atom in the five-sided ring to a carbon in the six-sided ring. This one bond can hold the six-sided glutarimide ring above the plane of the phthalimide molecule or below it, and depending on which direction the glutarimide ring is held, the first carbon in the glutarimide ring rises above or falls below the plane of the rest of that ring. A picture is worth a thousand words, so here, and good luck with it (because sometimes linked images get lost):
https://en.wikipedia.org/wiki/File:Thalidomide-structures.png
Now as it was belatedly discovered, the difference between the angle between the two units (and associated lift or descent of the glutarimide ring) makes the difference between the drug acting as a suppresser of morning sickness in pregnant women and a birth-defect cause in the fetus, and the horror of Thalidomide is that the racemic can change between the two states (each called an 'enantiomer'), through a process which is still not well understood. In the case of Thalidomide, the chiral shift took place within the human body.
Now as it happens, Thalidomide could be racemically separate, so that only the enantiomer which treats morning sickness was given to pregnant women... but because of the spontaneous (or seeming spontaneous) chiral shift, it is likely rather than merely possible that half of the dose would undergo the shift. So the drug was removed from the market in 1961. But it turns out that it was also an effective cancer treatment drug, and so it is back on the market, with treatments involving Thalidomide and other drugs, requiring risk assessment, because it can still cause birth defects if the woman who is treated (or her partner, since Thalidomide can be passed in semen).
Modafinil is a racemic structure, with a right-handed and left-handed form, but it can be racemically filtered. The right-handed form is an effective treatment for Narcolepsy, although the mechanism is not perfectly understood. The left-handed form is psychogenically inert, and it's major action seems to be to make the user's urine smell really bad. To add to the already burdensome information I've provided, I'll add that the enantiomer forms which are considered right-handed are designated with an "r-" prefix, while the left handed forms are prefixed with "s-". (see sidebar). So the purified version of modafinil, which contains only the right-handed enantiomer of modafinil sells under the generic name Armodafinil (brand name Nuvigil, among others). And that's what I was prescribed.
Armodafinil is treated as a class-3 narcotic, not because it demonstrates narcotic effect on humans, but because its effect falls loosely into a psychological categorization: it acts upon the brain in some way that causes negation of the drowsy effect of Narcolepsy (or, another way of looking at it would be that it "promotes wakefulness". This has led to some really dumb efforts by people who just don't know any better or just don't care, to claim that its wakefulness promoting effect has a side effect of promoting better memorization. I can tell you, from first hand experience that it doesn't. I'm 70, I've been taking it for 6 years, on and off, and by golly, my ability to memorize new information or recall stuff I've had in my head for decades is not even slightly improve, short- or long-term. If you meet me on the street, the odds I'll remember your face are high, but your name? feh! So don't take offense, please.
However, taking Nuvigil has allowed me to have something approaching a normal life. My father had Narcolepsy, and he'd drop out in the middle of a sentence (if he was sitting) and wake up anywhere from minutes to hours later, to continue the sentence. In my case, when I was off the drug during the COVID era, I did the same. My wife and kids coded it "unscheduled nap", and claimed it was cute, so I codify it as "bouts of unscheduled cuteness."
Promised sidebar, from the pedant department:
Since chirality involves two identical structures of identical components which, because of angles between components, out-of-plane, cause them to be significantly different, some form of identifying the difference was needed. There has already been a system in place for a long time, related to the glyceraldehyde molecule, where what we now considered right-handed was originally given a (+) prefix and (-) to the left-handed one. This was actually pretty cool, because years, later, in 1951, x-ray crystallography confirmed that there was a right-handed aspect to the (+) labelled form.
The two forms have since been labeled with an R/L system and an S/D system. In the latter, the letters are based on the Latin Sinister and Dexter terms for, respectively, left and right. The earlier system used the Latin Rectus as a cognate the English "to the Right", and "Laevo", Latin for "to the left".
