Now that the SSRIs have been in use long enough to be seen in perspective it is clear they have side effect differences from the TCAs, with some advantages, albeit modest. These advantages may not be as great some wish them, or perceive them, to be.
The overall discontinuation rate of SSRIs is 25%. Discontinuation rates of TCAs are very similar. These figures comes from controlled trials and may not be representative of the clinical situation or of longer term use.
Some serious side effects, eg GI problems, hyponatremia, seem to be higher with SSRIs than with TCAs.
Some SSRIs interact with other drugs (via cytochrome P450 enzymes) more frequently than do the TCAs. With paroxetine, fluoxetine and fluvoxamine this is such a potentially serious problem that doctors who do not have an adequate knowledge of cytochrome P450 enzyme interactions would be well advised to avoid these drugs where any possibility of an interaction is present.
There may be significant differences between the different SSRIs, both in side effects, efficacy and possibly toxicity. The nature of these differences may be partly understood by remembering that the TCAs are defined as a ‘class’ by virtue of their structural (tricyclic) similarity – some of their pharmacological actions are quite diverse. In contrast the ‘SSRIs’ are defined as a class by their action, not by their structure, which is quite different for each one.
It seems that patients who fail to respond to one SSRI may respond to a different SSRI — trying more than two SSRIs is probably not the best course; at this stage reassessment / a trial of a different class of drug / referral are likely to be indicated.
Now that the SSRIs have been in use long enough to be seen in perspective it is clear they have side effect differences from the TCAs, with some advantages, albeit modest. These advantages may not be as great some wish them, or perceive them, to be.
The overall discontinuation rate of SSRIs is 25%. Discontinuation rates of TCAs are very similar. These figures comes from controlled trials and may not be representative of the clinical situation or of longer term use.
Some serious side effects, eg GI problems, hyponatremia, seem to be higher with SSRIs than with TCAs.
Some SSRIs interact with other drugs (via cytochrome P450 enzymes) more frequently than do the TCAs. With paroxetine, fluoxetine and fluvoxamine this is such a potentially serious problem that doctors who do not have an adequate knowledge of cytochrome P450 enzyme interactions would be well advised to avoid these drugs where any possibility of an interaction is present.
There may be significant differences between the different SSRIs, both in side effects, efficacy and possibly toxicity. The nature of these differences may be partly understood by remembering that the TCAs are defined as a ‘class’ by virtue of their structural (tricyclic) similarity – some of their pharmacological actions are quite diverse. In contrast the ‘SSRIs’ are defined as a class by their action, not by their structure, which is quite different for each one.
It seems that patients who fail to respond to one SSRI may respond to a different SSRI — trying more than two SSRIs is probably not the best course; at this stage reassessment / a trial of a different class of drug / referral are likely to be indicated.
Recent Replies
Recent Topics
-
Website Feedback & Issues Thread
by Philip Dang2:45 pm 5 June 2022
-
Database of Doctors Accepting Referrals for considering MAOIs
by Philip Dang9:17 am 15 January 2022
-
Archived MAOI Food Interactions11:22 pm 4 March 2022
-
Frequency Asked Questions (FAQ)
by Philip Dang4:57 pm 5 January 2022
-
How to use this forum11:51 am 3 January 2022
Consider Donating to PsychoTropical
PsychoTropical is funded solely through generous donations, which has enabled extensive development and improvement of all associated activities. Many people who follow the advice on the website will save enormously on doctors, treatment costs, hospitalization, etc. which in some cases will amount to many thousands of dollars, even tens of thousands — never mind all the reduction in suffering and the resultant destruction of family, work, social, and leisure capability. A donation of $100, or $500, is little compared to those savings. Some less-advantaged people feel that the little they can give is so small it won’t make a difference – but five dollars monthly helps: so, do not think that a little donation is not useful.
– Dr Ken Gillman