08-31-2010, 06:40 PM
Status: SAS Member
Join Date: Apr 2010
Originally Posted by rocknroll714
Indeed, while the TCAs are generally thought to be quite sedating, they are also mixed in a complicated manner similarly to the MAOIs. They have two major sedating actions and two minor ones - the first two are antihistamine and α1-adrenergic-blocking properties, and the latter two are serotonin reuptake inhibition and 5-HT2A receptor blockade; then, they have norepinephrine reuptake inhibition as the major stimulating component and 5-HT2C receptor antagonism as a very minor one. The potencies of various TCAs in producing these effects varies considerably, and as a result, they have sometimes been categorized something like as follows:
- Tricyclic Antidepressants:
In general, all TCAs tend to be relatively sedating at first while the H1 receptor downregulates, but once it has fully desensitized (which it will, at least in my personal experience with mirtazapine), some TCAs like protriptyline and desipramine can indeed become quite activating. Apologies for not discussing this before, I didn't want my posts to get too complicated and thus confusing, but since you brought it up, here you are! :P
I found Nortriptilyne to even be far less stimulating than Protriptilyne. Nortrip wasn't sedating, but not as stimulating as Protrip. The side effect profile between the two was very different also.