PsychoTropicalResearch, serotonin and serotonin syndrome research.
Tricyclic antidepressants - Toxicity
Date Created: 14/01/1999 Last Modified: 19/01/2002 Last Checked: 23/11/2003
It is advisable to use TCAs (and neuroleptics) with due recognition of their toxicity and side effects as some current opinion suggests a legal claim of negligence may succeed if ‘newer and safer’ drugs are not tried first. There are a number of counter points to such views.
The risk of toxicity with any drug is likely to be effectively negated by good clinical management which may include:-- making sure a responsible person has charge of such drugs, and prescribing limited non-toxic quantities.
The egregious argument that to avoid toxicity one must, perforce, use an SSRI is transparently specious.
Note that statistics on relative toxicity remain incomplete and generalisations comparing “classes” of antidepressants (TCAs vs SSRIs or “new” drugs) are of limited validity because toxicity is not strictly a class effect.
Dothiepin is almost certainly the most toxic and may sometimes be contra-indicated as first line treatment or where suicidal risk is elevated. Next in toxicity come doxepin, (and the SRI or SNRI? venlafaxine), amitriptyline and nortriptyline. The safest are lofepramine and clomipramine (about 10 times safer than dothiepin).
It is interesting to note that clomipramine is ten times less likely to cause serotonin syndrome in over-dose than any of the SSRIs or moclobemide.
All text ©Dr Ken Gillman MRC Psych - PsychoTropical Research®
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