4DQSAR
Bluelighter
- Joined
- Feb 3, 2025
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N&PD Moderators: Skorpio | someguyontheinternet
That is the interesting thing about amitryptaline, it's other uses were discovered purely through serendipity rather than 'indication creep' which is common in medicines developed after the early 1980s.
It's like the first class of antidepressants, the MAOIs. They were trialled as treatments for tuburculosis and it was noted that many of the cohort of patients who were suffering clinical depression found significant relief.
They were the first and are very effective but the multiple toxicities and diet restrictions make them difficult to use clinically in a safe manner.
But 64 years after it's introduction, new antidepressants are compared with amitryptaline but often in a VERY dubious manner. For example, studies on paroxetine stated that it had 'similar effacacy to amitryptaline' BUT they were prescribing the control group tiny doses of amitryptaline and the test group the highest prescribabde dose of paroxetine... because medicinal chemistry isn't particularly ethical.
It's extremely difficult to model clinical depression in animals and it may well be the case that while the major action of amitryptaline is on extracellular serotonin and extracellular norepinephrine levels, it's likely that those other activities are also important to the action of the drug.
I was told that only one in around 10,000 candidate antidepressants is ever licenced for use in man. So while some even made it to stage 2 human trials which roughly means they are likely not toxic, an enormous number aren't developed further simply because they don't work.
All manner of different targets have been suggested but it seems that amitryptaline is still considered the 'gold standard'. The only issue is that it IS toxic in overdose. Well, if you are concerned that a patient may intentially overdose on a tricyclic, only issue a 7 day supply. Yes, they could hoard the medication but I would suggest that anyone who is prepared to plan for weeks to end their own life (as opposed to someone having a dreadful moment and necking all the pills) will find another way.
So by no means perfect, but still considered the most effective antidepressant. By that, I mean it works for around 43% of patients. Yes, even the best works for less than half the people prescribed it.
But the SSRIs were designed to tackle the toxicity issue and I contend that they did so at the expense of effacacy. Certainly none has ever claimed to be better.
The sedating effects even at 25 mg for me was intense. I don’t know how people could be awake on higher doses.
That's why it's often prescribed to be taken at bedtime. Most people develop tolerance to the sedative side-effects but it's one of the issues that the SSRIs were intended to solve. But I contend that one of the most common symptoms of clinical depression is anxiety and for such people amitryptaline can treat that symptom very quickly.
Nortryptaline is supposed to be less sedating and I suspect it was introduced to deal with the sedation some people suffer and it is a metabolite of amitryptaline, but I'm not sure how the tricyclics compare. I don't think anyone has been able to prove one is superior, or, rather, not is reliably superior.
It is evident from a cursory inspection of the structures of imipramine and chlorprothixene, both inspired by the phenothiazines, that the stage was set for the synthesis of amitriptyline. In fact, no less than 15 independent groups in Europe and North America were involved in the study on amitriptyline and related dibenzo[a,d]cycloheptenes. The competition to synthesize amitriptyline was so fierce that five applicants were involved in a patent interference declared in the United States Patenbt office.
I can believe it. No doubt someone had noted that amtohistamines such as promethazine had quite a robust antidepressant action BUT was not optimized for that indication.
I wonder if the competition was for the FIRST synthesis so that one partly holds the patent rights OR was it the fact that their success meant a 'lively' industry in finding cheaper synthetic routes culminated with echical standards even lower than is common to medicinal chemists?
Promethazine is another one that is too ignored imo both in psychiatry and physical medicine. It’s considered old, clunky and anticholeragenic. Except for pregnancy associated nausea and vomiting. But it has instantly given me relief from anxiety. Can’t function on it directly because it is too sedating, but it has an immediate anxiolytic effect that is beyond just sedation, and I wake up with a much better mood from it.
It's still available in many nations. I have a box of it in front of me.
Always have a box handy - lasts me many months but handy. I just buy it at the local Boots.