Posted by zeugma on March 27, 2004, at 14:50:48
In reply to Re: Help: WHICH IS THE LEAST SEDATING SAFETEST TCA? » King Vultan, posted by Sad Panda on March 27, 2004, at 13:00:17
>Nortriptyline, OTOH, has a relatively strong NE reuptake blockade that is at least one order of magnitude, and probably more like two orders of magnitude above its ACh blockade. In theory, anyway, a patient would need to take a proportionally larger dose of nortriptyline to experience the same ACh effects as one would on imipramine because the NE reuptake blockade will dominate the pharmacologic profile at low dosages. Grasping this concept is key to understanding how a drug's in vivo behavior (in the body) differs from its in vitro behavior (in the laboratory). There is a ton of information available at www.preskorn.com looking at drug behavior from this perspective.
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> Well, be that as it may, I've taken nortriptyline and believe I did suffer some anticholinergic effects on it. I'm not really sure, though, because it could just have been sedation from its histamine blockade. Whatever the case, the molecule clearly did not agree with me, in sharp contrast to my experience on the imipramine metabolite desipramine, which is the only drug I've tried that had few enough side effects for me to able to tolerate a full therapeutic dose of it.>I did not experience any anticholinergic effects from nortriptyline until I got above 50 mg/day. The NE reuptake blockade effects (impulsivity, jitteriness, 'activation') began less than a week after starting the drug at 20 mg/day.
The antihistaminic effects became noticeable at some point between 20 and 50 mg/day. They are relatively weak (for me, anyway) which means that I have to augment with buspirone to get a strong sedative effect.
It is hard to tell what is an anticholinergic effect and what is a 'pseudo-anticholinergic' effect (as Stephen Stahl calls it) from NE reuptake blockade. The symptoms I'm calling anti-cholinergic (constipation, dry skin, dry mouth) became much more frequent and persistent since adding Strattera. Strattera has no direct effect on muscarinic receptors.
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poster:zeugma
thread:328391
URL: http://www.dr-bob.org/babble/20040325/msgs/329125.html