Originally Posted by
owainm
I read a lot about QT prolongation and ssris mainly with Citalopram/Escitalopram at high doses. Just wondering if this is something that is an issue with Prozac do I need to be concerned about it?
There are cardiologists who dispute that it's even a problem with citalopram and escitalopram, however, according to CredibleMeds which maintains the data base of meds which may affect QT prolongation for the FDA, fluoxetine has only a 'Conditional Risk', the lowest category, i.e. it doesn't usually affect it on its own, but may increase the risk of prolonged QT intervals in combination with other factors:
Conditional Risk of TdP - These drugs are associated with TdP BUT only under certain conditions of their use (e.g. excessive dose, in patients with conditions such as hypokalemia, or when taken with interacting drugs OR by creating conditions that facilitate or induce TdP (e.g. by inhibiting metabolism of a QT-prolonging drug or by causing an electrolyte disturbance that induces TdP).
So you're unlikely to have issues from taking fluoxetine alone. Btw - SSRIs/SNRIs and other serotonergic ADs are mild anticoagulants that may reduce the risk of heart attack and ischaemic (blocking) stroke, but may slightly increase that of the much less common haemorrhagic stroke, so there can be positives from taking them too.
Is it more likely to happen the longer you have been on a med? i.e. is long term use of an SSRI going to cause heart problems etc
Length of time on the med doesn't increase the risk from meds known to prolong QT interval, however, advancing age may. Fwiw, I've been on a very high dose of dosulepin, aka dothiepin, since 1995. A couple of decades ago it was the most prescribed AD in Britain with about 70% of the market until it became apparent that it is highly cardio toxic. So much so that it has been removed from the British National Formulary and the UK drug regulator has recommended only psychiatrists and other special-care doctors be allowed to prescribe it to new patients. Despite its toxicity, my mid 70s heart is working as well as it ever did. The time may come when the decrepitude of advancing age may render it too risky to take, but atm I'm not that concerned.