Celexa and Vistaril dangerous?

[melfish]

My GP prescribed 10mg celexa and 25mg Vistaril q.i.d for anxiety. I've been taking this for several weeks along with gabapentin 700mg/day. Tonight I google drug interactions and apparently celexa and vistaril should not be taken together as they both increase the risk for torsades de pointes. Every site I went to warned against it, saying there was a major interaction. How did my doctor not know this? How can I trust her? I am tempted to just bin all the drugs and focus on diet and exercise

[AntsyVee]

Double check with your pharmacist. My doc has also prescribed meds that Google has told me should not go together, but I’ve taken them and it was fine. The dosages were not enough of either one to cause issues.

[panic_down_under]

How did my doctor not know this?

I'm sure she is well aware of the potential interaction, as would have been your pharmacist who is supposed to be the gatekeeper guarding against potentially dangerous drug combinations. But as with all medications, the dose is the thing, as is your state of cardiovascular health. Long QT syndrome and torsades de pointe may be an issue at high doses of each med especially if there is a potential risk of some heart diseases, but are only a remote possibility at the sub therapeutic dose of citalopram and low dose of hydroxyzine you're on. It is by no means an unusual combination, and arguably a better one than citalopram plus a benzodiazepine.

Also be aware that while they were right in this case, online drug interaction sites are far from foolproof. For example many will list the citalopram + mirtazapine combination as likely to trigger serotonin syndrome/toxicity (SS, ST). They are all wrong. Not my assertion, but that of Dr Ken Gillman, one of the two leading experts on the syndrome:

As I have pointed out before, drugs like bupropion and mirtazapine, that have no significant serotonergic activity, are no more likely to cause ST than is vitamin C. This scenario has already been enacted, over a decade, with the antidepressant mirtazapine, which was claimed, erroneously, to have serotonergic activity. Many poor quality case reports of ST with mirtazapine were published. This probably led to misdirected treatment of overdoses, some of which may have caused morbidity. It took several reviews to correct this error and establish that mirtazapine cannot cause ST

PK Gillman, 2010 PDF

Apparently, his reviews have not yet reached the compilers of the interaction websites. Maybe they are on a very slow boat to China.

And lest there be any doubt, the other leading expert, Ian Whyte and his team at the Hunter Toxicology Group, who wrote the book on diagnosing ST, agrees (5-HT=serotonin):

In some cases this has led to reports of serotonin toxicity for drugs that, from well-defined receptor binding studies, are unlikely to cause increased levels of CNS 5-HT. Important examples include the 5-HT2A receptor antagonist olanzapine and the 5-HT receptor antagonist mirtazapine.

The Hunter Serotonin Toxicity Criteria

Drug interaction sites claims should only be considered as a general indicator to follow up with a physician or pharmacist, but holy writ.

[melfish]

Thank you, panic. I was hoping you would chime in. I wore a 48-hour holter last year and no long QT was detected on that. The plan is to titrate me up on the citalopram, but I think I will stop the vistaril in any case. It makes me sleepy as heck, but also sort of wired, and I'm not crazy that it's an anticholinergic that is messing with my short-term memory already. It is good for sleep though. My main issue is anxiety, not depression, and insomnia is a problem. Does citalopram even help with anxiety? (I'd still rather a benzo, but get why doctors are reluctant to prescribe)
Anyway, thanks so much for your explanation.

PS I woke in the middle of the night this week to go to the loo, and the top part of my vision was black in both eyes. Is this a side effect you are aware of for either of those meds?

[AntsyVee]

:P Mel... not even a hi for me

[melfish]

Sorry! How are you, Antsy?! Been a while

[AntsyVee]

I can't let Ian think he's more popular than me, it'll go to his head

I'm doing pretty well. Yeah, last school year I was super busy... It's quieted down more this year, so I'm trying to spend more time on here. You still living up North?

[melfish]

Yep, and quietly despairing over the state of this country between anxiety meltdowns. So nothing's changed

[AntsyVee]

LOL yes, Terry and I have been discussing international politics with Mezzi here

[panic_down_under]

Does citalopram even help with anxiety?

It sure does, but as with everything about ADs, YMMV. As a generalization, SSRIs are more effective for anxiety than depression.

(I'd still rather a benzo, but get why doctors are reluctant to prescribe)

If you only have anxiety occasionally, i.e. once a week or less most of the time, plus the odd bad week, then BZDs would be the better option, but they are counterproductive in daily use as they block hippocampal neurogenesis which is the underlying cause of anxiety and depression.

PS I woke in the middle of the night this week to go to the loo, and the top part of my vision was black in both eyes. Is this a side effect you are aware of for either of those meds?

No. Don't recall it ever having been mentioned before. Both citalopram and hydroxyzine may cause blurry vision, and, as with many ADs, citalopram may dilate the pupils. There are several other listed visual side-effects, all rare, but nothing like what you describe.

I wouldn't read to much into this if it's only occurred once. Most of what we see doesn't come directly from our eyes. The optic nerves don't have enough 'bandwidth' for that. Mostly, the eyes just transmit shapes and lines and the brain's visual cortex 'colours' in the rest. It doesn't always get it right and can be extra fallible soon after wakening. Definitely raise it with your doctor if it continues to happen, but, to quote the Bard, it's probably much ado about nothing.