Prolonged QT intervals and medications like antipsychotcs and SSRIs

[jim45259]

Recently I started taking an antipsychotic called Latuda, it was 1 pill of 40mg a day, I only took it for 6 days, so that's 6 pills, and then I changed my mind about taking them because of the fear of side effects, the main fear I have is that they can prolonge QT intervals.

I decided to go back to the pill I use to take instead which is Luvox, which is an SSRI. I wasn't feeling well, so I didn't wait much, the day after I stopped taking Latuda  40mg pill, I took a 50mg of Luvox, I'd say there was about 26 hours inbetween the time I took the last 40mg pill of Latuda, and the first 50mg pill of Luvox.  

I'm concerned that this could of been harmful, that I could have got a prolonged QT interval. It's been a couple of days since that happened, and now I'm just taking Luvox, 2 pills of 50mg a day, 1 with breakfast and 1 with dinner.

Is the Latuda out of my body now, am I on Luvox normally now? Should I be concerned about what it could of done to me, especially in regards to prolonged QT interval, what should I do going foward?

[jim45259]

I'll certainly tell my doctor about this tomarrow. I send you a message without reading this last answer of yours. I look Luvox for years and many times I was neglected it, usually skipping dosages or taking less than I was suppose to, I guess it can be dangerous, some people get withdrawl symptoms and things like that. I never felt too much of anything.

In terms of the qt interval, do you think it can have any affect on that? Like the prolonging of the QT stays with you, because you changed the dosage of the medicine too much? Maybe it's a weird question but I have anxiety and I worry about things.

[spade22]

I looked up the half life of Latuda and it is about 18h.  This means that after 3 days, no appreciable amount of the medication is in your system.   There should not be any interaction with the Latuda that you took on July 6th, but I'm not a phamaracist so I'm not the best person to seek advice from regarding this. ;-)

Based on your questions, I am concerned that you made these changes to your medications without consulting with your doctor.  It's really important to discuss any changes you want to make with a doctor  so you can get a clear set of instructions on the best way to go about doing it.  Sometimes, it can be very dangerous to abruptly stop taking a medication.

[jim45259]

Thanks for the response, I'm concerened about the mixture. You're not suppose to take Luxov and Latuda together, it increases the chance of certain effects.

I took one 40mg pill of Latuda for six days and stopped and then about 40 hrs later took one 50mg pill of Luvox, and have been taking Luvox since then for a couple of days. I said, 26 hours at first but I counted wrong.

Should I have waited longer before taking Luvox? How long before the Latuda is out of my body? I took my last pill of Latuda Tuesday, July 3rd at maybe like 11:00pm and my first pill of Luvox Friday July, 6th, around 12:00am.

[spade22]

Hi there!

There is a list of medications, and medication-medication interactions, that have a "potential" side-effect of prolonging the QT interval; "potential" side effect means that this will only effect some people.  This potential side effect isn't  a problem unless a person has LQTS (a rare, inherited disorder) or they have a borderline high, or near borderline high, QTc interval to begin with in which case this can cause a case of "acquired LQTS".  With acquired LQTS, the QTc will return to normal once the medication prolonging the QTc interval is out if their system.

Have you ever had your QTc measured?  Have you discussed your concerns with your doctor?  It would be very easy to determine your QTc before and after starting medications, which would tell you whether you are part of a rare, high risk group of people that should not take that medication.  The odds are, that you do not fall into this group and so can take medications that your doctor thinks will benefit you.