Posted by Brainbeard on December 30, 2010, at 16:37:35
In reply to low platelets, posted by Chris Crosby on December 29, 2010, at 11:47:16
.... and doctors are often hardly aware of it.
From http://www.ncbi.nlm.nih.gov/pmc/articles/PMC55923/:
'Serotonin potentiates platelet aggregation. Selective serotonin reuptake inhibitors decrease serotonin uptake from the blood by platelets. Because platelets do not synthesise serotonin, these inhibitors decrease the amount of serotonin in platelets. Case reports suggest that serotonin reuptake inhibitors are associated with a variety of bleeding events.'
The study of De Abajo is the landmark study for this link between SSRI's and bleeding: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC28262/
I have been reading up on this, and the amount of platelet inhibition is in proportion with the amount of serotonin reuptake inhibition. Lexapro is a strong SRI, which means it will inhibit platelet function. Not only (S)SRI's, but also 5HT2A-antagonists inhibit platelet function. This is my finding, which I have deduced from the fact that several 5HT2A-antagonists turned out to be associated with an unexpected risk of bleeding plus the fact that 5HT2A receptors play a key role in platelet aggregation.
(S)SRI's by themselves pose only a low risk for gastrointestinal or other types of serious bleeding, but the risk increases dramatically when (S)SRI's are combined with NSAID's (like Ibuprofen). If I need to take an NSAID (in case of severe toothache, for instance), I will take a stomach protector (omeprazole, proton pump inhibitor) with it - but I had to ask for these myself, my doctor wasn't aware of the risk.
I have an anxiety disorder, and the increased risk of gastrointestinal bleeding on S(S)RI's kept me back from taking therapeutic doses for a long time. I accept the risk now, realizing that my neurotic anxiety magnifies the (impact of the) risk by a factor thousand.
See also:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1884264/
Current meds: clomipramine 225mg, fluvoxamine (Luvox) 50mg, dexamphetamine 5-10mg, bethanechol 20-60mg. As needed/wanted: oxazepam 5-20mg.
poster:Brainbeard
thread:975155
URL: http://www.dr-bob.org/babble/20101218/msgs/975295.html