Chemistry: Compare these 2 pictures. Only the bonds are different.
 

Sinequan (Doxepin): Side Effects, Interactions, Warning, Dosage & Uses
SINEQUAN (doxepin HCl)
See the lines in the hexagon.

Silenor - FDA prescribing information, side effects and uses
SILENOR (doxepin hydrochloride)
Scroll to number 11. DESCRIPTION for the picture of Silenor.


(The three complete hexagons make a tricyclic antidepressant.)

Hubby is a chemistry buff. He says that the difference has to do with the
location of the double bonds on the side of the hexagon of the molecule.

The locations of the double bond make a difference in the strength of the molecule
but the molecule is not fundamentally different: has the same
number of Hydrogen, Oxygen, Nitrogen, and Carbon
ELEMENTS.


I have looked at this a million times over the past few days and do not see the difference.
I did understand it when hubby explained this to me in words
instead of pictures a few minutes ago. (He is more visually oriented than I am.)

=-=-=-=-

(It is possible that the two pictures I found are not clear.
I apologize. It is best I could do
without posting a screen shot :) --- not allowed on this site.

M

This link explains the notation of the double bonds in a benzene ring:

Line Drawings

The benzene ring is not fixed-- it is always in motion. In my day the circle inside the ring showing in the link above was how it was commonly written.

Doxepin is doxepin or the FDA would not allow that name on the drug for identification. There would be another variant type name. The hydrochloride is even the same, and if that were different, it could denote a slightly different solubility, rate perhaps.

over my head
bobby

Mrs. D says that the two drugs (Silenor and Sinequan) have the same name: Doxepin.

That is the important part.

Sinequan is cheap.

"over my head
bobby"

This is not easy to explain.

In a benzene ring (a hexagon of six carbon atoms) the electrons between the carbon atoms are not in fixed positions; rather they are "smeared out" across the ring. This is what is indicated in the link that mrsD provided (a hexagon with a circle in the middle of it).

In the links which Mari provided for the structures of Sinequan and Silenor there are different patterns of electrons in the two benzene rings. This is confusing - it would have been clearer to use the hexagon/circle image as in mrsD's link.

The bottom line, as mrsD has emphasised, is that Sinequan and Silenor are chemically identical (they are both doxepin) and so will have identical pharmacological properties.

Thanks, Mrs D and Kiwi!


M

thanks so very much
bobby