# sildenafil citrate, anyone? **URL:** \ **Category:** Factual Questions\ **Created:** [November 29, 2000, 3:41pm UTC](https://boards.straightdope.com/t/sildenafil-citrate-anyone/43200 "2000-11-29T15:41:20Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![omni-not](https://avatars.discourse-cdn.com/v4/letter/o/8dc957/32.png) [@omni-not](https://boards.straightdope.com/u/omni-not)\ **Post date:** [November 29, 2000, 3:41pm UTC](https://boards.straightdope.com/t/sildenafil-citrate-anyone/43200/1 "2000-11-29T15:41:20Z")
You probably better know it as Viagra. How do they come up with those wacky ‘scientific’ names? Now, I know citrate is nothing new, but _sildenafil_?!?! ---
**Author:** ![LazarusLong42](https://avatars.discourse-cdn.com/v4/letter/l/87869e/32.png) [@LazarusLong42](https://boards.straightdope.com/u/LazarusLong42)\ **Post date:** [November 29, 2000, 4:55pm UTC](https://boards.straightdope.com/t/sildenafil-citrate-anyone/43200/2 "2000-11-29T16:55:18Z")
Often, they have to do with the actual chemical structure of the compound. Take acetaminophen (commonly known as Tylenol). It presumably has an acetyl group (CH[sub]3[/sub]CO), an amino group (NH[sub]2[/sub]) and a phenyl group (a benzene ring). Other times, it’s presumably related to function or other properties of the compound. However, I must admit I’ve no idea where many of the names come from, as those only cover (I’m guessing) about half of them. As to _why_ they do this… well, have you ever seen an IUPAC chemical name? For sildenafil specifically, I’m looking at the structure right now (goto [Chemfinder](http://www.chemfinder.com) and type in “sildenafil” in the search box). Sildenafil contains: An adenine group (which substituents), which accounts for the “dena”; A sulfate group: “sil” A phenol: “fil” Those last two are, I admit, stretches, but the first at least makes perfect sense. FTR, if you’re looking at the structure, The two rings on the right are the adenine; the ring in the middle is phenol; the bit with the “S” in it is sulfate. However, over to the left there’s a piperazine ring which isn’t in the name at all. \ LL \<-- Why, yes, I _am_ a biochemist, why do you ask? ---
**Author:** ![LazarusLong42](https://avatars.discourse-cdn.com/v4/letter/l/87869e/32.png) [@LazarusLong42](https://boards.straightdope.com/u/LazarusLong42)\ **Post date:** [November 29, 2000, 5:48pm UTC](https://boards.straightdope.com/t/sildenafil-citrate-anyone/43200/3 "2000-11-29T17:48:48Z")
OK, I checked it out. The IUPAC name for acetaminophen is: N- **acet** yl-4- **aminophen** ol. Easy enough, right? The IUPAC name for sildenafil citrate is: 1-[[3-_(6,7-dihydro-1-methyl-7-oxo-3-propyl-1H-pyrazolo [4,3-d]pyrimidin-5-yl)_-4-ethoxy **phenyl** ] **sulfonyl** ]-4-methylpiperazine citrate [self-hijack] (This is why we don’t call drugs by their IUPAC names, and have to come up with something like “sildenafil.” You thought _that_ was scientific-sounding? Customer at pharmacy counter: “My doctor told me I should pick up some 1-3-6,7-dihydro-1-methyl-7-oxo-3-propyl-1H-pyazolo…” Pharmacist: “Is there one bracket or two in there, before the ‘three’? I need to know whether to give you this really strong painkiller or Viagra.” Customer: “Ah, I’ll take both.”) [/self-hijack] Back to topic: In the IUPAC name, I’ve set off some bits. The bit in italics is the adenine part. So even at that, we’ve shortened that whole chunk to just “adenine” (or possibly “adenyl”) and then fully down to - **dena** -. Then: The first bit in bold (phenyl) loses the -en- to become **phyl** , or just - **fil** when pronounced. The second bit in bold (sulfonyl) loses the -ulfon- to become **syl** , or **sil** - when pronounced. Thus: **sil-dena-fil** That’s the best guess I can come up with. Anyone else care to try? LL ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [November 29, 2000, 6:46pm UTC](https://boards.straightdope.com/t/sildenafil-citrate-anyone/43200/4 "2000-11-29T18:46:03Z")
When a company develops a new drug they make up two names for it. The first, viagra, is the brand name under which the substance is sold. The second, sildenafil, is a generic name for the substance that anyone who manufactures or sells it can use. As an example of utility: anyone can sell gelatin, but only the Jello folks can sell Jello. There’s no requirement that the brand name or the genric name have anything to do with the structure of the drug. But for the whim of a marketing department, viagra could have been named “dirty socks”. ---
**Author:** ![LazarusLong42](https://avatars.discourse-cdn.com/v4/letter/l/87869e/32.png) [@LazarusLong42](https://boards.straightdope.com/u/LazarusLong42)\ **Post date:** [November 29, 2000, 7:24pm UTC](https://boards.straightdope.com/t/sildenafil-citrate-anyone/43200/5 "2000-11-29T19:24:08Z")
**Squink** , you’ll find that the generic names generally do have some meaning/relation to the real compound name, whereas, yes, the trade name (Viagra) could be damn near anything. LL ---
**Author:** ![omni-not](https://avatars.discourse-cdn.com/v4/letter/o/8dc957/32.png) [@omni-not](https://boards.straightdope.com/u/omni-not)\ **Post date:** [November 29, 2000, 7:42pm UTC](https://boards.straightdope.com/t/sildenafil-citrate-anyone/43200/6 "2000-11-29T19:42:10Z")
**Lazarus** : Forgot to mention that I never took a single chemistry course…😃 Thanks for the info. Ditto for Squink. ---
**Author:** ![Yeah](https://avatars.discourse-cdn.com/v4/letter/y/dbc845/32.png) [@Yeah](https://boards.straightdope.com/u/Yeah)\ **Post date:** [November 30, 2000, 12:54am UTC](https://boards.straightdope.com/t/sildenafil-citrate-anyone/43200/7 "2000-11-30T00:54:15Z")
So how come N-acetyl-4-aminophenol is “paracetamol” in the U.K.? ---
**Author:** ![Smeghead](https://avatars.discourse-cdn.com/v4/letter/s/f1d935/32.png) [@Smeghead](https://boards.straightdope.com/u/Smeghead)\ **Post date:** [November 30, 2000, 2:11am UTC](https://boards.straightdope.com/t/sildenafil-citrate-anyone/43200/8 "2000-11-30T02:11:39Z")
> [@](#): > > \*Originally posted by Yeah \* > \*\*So how come N-acetyl-4-aminophenol is “paracetamol” in the U.K.? \*\* Phenol is a benzene ring with an alcohol group on it. “Para” is the same as “4” when talking about benzene rings - it means it’s attached to the 4th carbon, counting from the one with the alcohol group on it. So, para = 4, acet = acetyl, am = amino, and ol = phenol. There you go. Isaac Asimov once wrote an interesting essay on this question. He took the name “paradimethylaminobenzaldehyde” and traced back each syllable to its root. For instance, one of them is related to the word for “white” in Arabic because it’s found naturally in whitish crystals. Wish I could remember where I read it… ---
**Author:** ![Sublight](https://avatars.discourse-cdn.com/v4/letter/s/439d5e/32.png) [@Sublight](https://boards.straightdope.com/u/Sublight)\ **Post date:** [November 30, 2000, 2:40am UTC](https://boards.straightdope.com/t/sildenafil-citrate-anyone/43200/9 "2000-11-30T02:40:10Z")
> [@](#): > > \*Originally posted by LazarusLong42 \* > \*\ ***Squink** , you’ll find that the generic names generally do have some meaning/relation to the real compound name, whereas, yes, the trade name (Viagra) could be damn near anything. > > LL \*\* In fact, there has been a trend recently among pharmaceutical companies (in the US, anyway) to make the brand name as unrelated as possible to the generic name. This is so that when the patent expires and other companies can start selling the generic (or if FDA regulations change, allowing the drug to be sold over the counter), the original company retains the advantage of a well-known brand name. Competing companies, OTOH, must build up their own brands from scratch, which takes time and money. –sublight.