Posted by Sad Panda on February 5, 2004, at 3:49:14
In reply to Re: does this go away? Is this normal, posted by on-the-wave on February 4, 2004, at 14:47:40
> My second pdoc told me i could take 800mg of effexor and it wouldn't harm me. Is this true. As above no-one knows the answer, but where did this pdoc get this information?
>I have heard of pdocs going up to 1000mg!
There is a great little read here http://www.psychotropical.com/notes/589.html about how Efexor barely qualifies as an SNRI.
Here is a snipet on NRI strength:
"Indeed, in vitro venlafaxine is a weaker noradrenalin reuptake inhibitor than is fluoxetine (and some other 'SSRIs'). Fluoxetine is of course marketed as an selective serotonin reuptake inhibitor.
In summary we have the anachronism that some drugs marketed as selective serotonin reuptake inhibitors are more potent noradrenalin reuptake inhibitors than venlafaxine, which is marketed as a serotonin and noradrenalin reuptake inhibitor (SNRI). This anachronism is only partly explained away by 'selectivity' (ie NA vs 5-HT potency) and different dose ranges.
Noradrenalin reuptake inhibitor potency ***
Desipramine 0.83 most potent
Amitriptyline 35
Fluoxetine 240
Venlafaxine 1060 weakest"A snipet on toxicity:
"Venlafaxine seems to have greater toxicity and more severe withdrawal effects.
Recent data (12/00) from 456 admissions with antidepressant poisoning; numbers:--
venlafaxine (51), tricyclic antidepressants (excluding dothiepin*) (172), SSRI (233), dothiepin (81).
* because it is so much more toxic than all the othersOdds ratios (95% CIs, p) for:--
Seizures
Venlafaxine vs TCAs-- 4.4 (1.2 – 16.6, p = 0.02)Prolonged QRS (to &Mac179; 100 ms)
SSRIs vs TCAs 0.3, (0.2 – 0.6, p < 0.0001)
TCAs vs venlafaxine 0.6 (0.3 – 1.4, p = 0.31)Serotonin syndrome
venlafaxine vs TCAs 35.4 (7.6 – 325.3, p < 0.0001)
SSRIs vs TCAs 20.4 (5.2 – 174.9, p < 0.0001)Conclusions: Venlafaxine in overdose seems to be pro-convulsant, even more than TCAs (whereas SSRIs are much less so) and also cardiotoxic.
Venlafaxine is also a lot more likely to cause serotonin syndrome than either TCAs or SSRIs; this is unexpected since it is generally a weaker SRI. This would fit with it having another mechanism of action as mooted above."I am taking Efexor 225mg + Remeron 30mg. Efexor is making me a whole lot happy than I use to be, but it is strugling to give me any motivation. I will go up to 375mg & then I will try something else.
Cheers,
Panda.
poster:Sad Panda
thread:13781
URL: http://www.dr-bob.org/babble/20040204/msgs/309630.html