February 11, 2005 11:51 AM   Subscribe

For those on SSRIs, does anything weird happen if you accidentally miss a dose?
posted by anonymous to Health & Fitness (39 answers total) 2 users marked this as a favorite
Not to me. Now, if I go two days, I start to get the "zaps." Very unpleasant.
posted by pardonyou? at 11:54 AM on February 11, 2005

When I mess a Celexa dose (currently 50mg) I crash fast: unable to pull my shit together at all for the day, really spacey, various unhealthy feelings about myself.

When I was on Effexor, missing two dosages was akin to an acid trip. Interesting, but not exactly pleasant.
posted by five fresh fish at 11:55 AM on February 11, 2005

No. One of the great things about SSRIs is their fairly long half-life. Even the shorter-lifed ones take at least a day to lose a significant amount of concentration (I'm constantly playing with the dose, anyway...). I suppose if you missed a dose, you could do nothing, or take almost double the next's not going to make a whole lot of difference.
posted by ParisParamus at 11:56 AM on February 11, 2005

Actually, let me clarify that. First, I'm not an MD. Second, 50mgs is a whole lot of Celexa. My thought, above, contemplated a normal dose of half that. Take, perhaps 125%.
posted by ParisParamus at 11:58 AM on February 11, 2005

a friend of mine gets the zaps and nightmares after missing a single dose. she thought she was totally bonkers, until she talked to her doctor about it and he confirmed that yes, that happens to some people.
posted by crush-onastick at 12:16 PM on February 11, 2005

If it's Celexa, Lexapro, or Prozac, it's a non-event. As for the others, I guess you'll know if you're zapping. I've actually found that normal aspirin helps moderate Celexa withdrawal (involuntary).
posted by ParisParamus at 12:21 PM on February 11, 2005

I get spacey, lethargic, and irritable after about 3 days of missed dosages.

As for "zaps", what are they?
posted by LouMac at 12:35 PM on February 11, 2005

Zaps are a withdrawal symptom associated with some of the SSRIs; like little pulses of consciousness. I think they're somewhat similar to what excessive caffeine + lack of sleep may exhibit. At least, I think...
posted by ParisParamus at 1:01 PM on February 11, 2005

Zaps are a withdrawal symptom associated with some of the SSRIs; like little pulses of consciousness. I think they're somewhat similar to what excessive caffeine + lack of sleep may exhibit. At least, I think...

Not sure if that's consistent with what I experience, but for me they're like little electrical "zaps" in my head. They don't hurt necessarily, but they're not at all pleasant, they're very annoying, and the frequency increases the longer I get from the last dose. (By the way, I'm on Celexa).
posted by pardonyou? at 1:30 PM on February 11, 2005

It takes a few days for me to get them, but I also get the zaps as pardonyou? describes above. Like itty bitty seizures.
posted by Ruki at 1:50 PM on February 11, 2005

After three days without Paxil, I feel like I've turned into the Lizard King. You cannot skip does of that stuff without feeling like you are going crazy. Unfortunately for me, nothing else works.
posted by lilboo at 2:00 PM on February 11, 2005 [1 favorite]

The SSRI's have very, very different half-lives. In general, the withdrawl feelings are worst with Effexor, Paxil, and best/nonexistent w/ Prozac. Dosing and an individual's metabolism matter a lot.

anon, the simple answer to your query is an unqualified yes, but it would help to know what you are feeling and what drug/dose you are on.
posted by docpops at 2:05 PM on February 11, 2005

I've heard the "zaps" referred to as "brain shivers" on all sorts of message boards dealing with depression/anxiety meds. And I get them when I miss a dose of Effexor. Plus I get extremely nauseous, dizzy, alternating chills/sweats, pin-sized pupils and jaw-clenching. I also get all of these as a normal side-effect from the Effexor, but they're at least 10 fold worse when I skip a dose.

I'm hoping to transition off of Effexor soon, as it isn't working for me any more. To paraphrase a well-known, deceased funk celeb, "Effexor is a hell of a drug."
posted by macadamiaranch at 2:42 PM on February 11, 2005

Prozac has a really long half-life. In fact, some doctors recommend taking a "holiday" off the drug for a day or two if you experience the sexual dysfunction side effects and have a "big date" coming up. I have also heard of "skip every other day" as a way of titrating your dose if you're working on moving to a lower dose.

I can't speak to any of the other drugs - those "zaps" sound nasty!
posted by matildaben at 3:05 PM on February 11, 2005

This whole thread is a great testimony re: why to avoid SSRIs at all costs.

I was on Zoloft for six months and I missed a day now and again; nothing happened. But when I started stepping down my dosages (from, IIRC, 50mg -> 25mg) -- without my doctor's guidance/approval/whatever -- I did get very drifty and disoriented occasionally. That went away about six months after I stopped the drug completely.

I'll never take that crap (any SSRI) again. Someday as a culture we'll look back in horror that we ever did.
posted by xmutex at 3:42 PM on February 11, 2005

xmutex, I truly disagree with you. Celexa has helped me significantly (I'm not sure it shows on the outside, but it does to me); it's a very forgiving drug, and I would recommend it to someone without much qualification. Not even much of an intimacy issue; in fact it's been a positive.

Question: given its long half-life, how can going off Prozac for a couple of days have any effect?
posted by ParisParamus at 3:58 PM on February 11, 2005

"titrating" ?
posted by ParisParamus at 4:00 PM on February 11, 2005

Paxil withdrawal is well-documented and though it was a huge help at the time, I refused it after going off it once.

Celexa -- only if I missed two consecutive doses. Prozac...No, due to the long half-life (as observed above). Many doctors give you prozac when weening you from other SSRIs.

Now that I am on Lexapro (which contains only one of the two isomers in Celexa -- ideally the effective isomer) I find that if I miss one dose by the next day (day after missed dose) I experience headaches and personal withdrawal symptoms.

I thought this was odd and my psychiatrist said that it isn't customary but the brain is a unique organ and many people have different reactions.

So, while we may have shared experiences you could experience a plethora of symptoms that haven't been the same for others in the same experience.

Best advice, talk to a psychiatrist. An M.D.
posted by Lola_G at 4:14 PM on February 11, 2005

Just one quick note: if you skip/miss a dose DO NOT double up. You'll notice this warning in the package insert and the notes to doctors that come with the freebies you get from the doctor (and here). Dosage for SSRIs is a really tricky thing, and it is possible to take a bit too much and end up having a hypomanic episode. You do not want that, it is not fun!
posted by nprigoda at 5:02 PM on February 11, 2005

Fist of all, DON'T double up your dose if you miss one, just take the next dose. It may not do anything to some people if they double, but others will be in for a pretty rough time, which can last several days.

Does anything weird happen? It may, it's really different for everyone. People are right that in theory, the half life of SSRIs should mean that missing a dose doesn't do much, and in terms of the theraputic effect, that's true. The side effects of missing a dose can range from nothing at all to very uncomfortable, you'll know pretty quickly which boat you're in.

The good news is that even if you have pretty severe side effects from missing your dose, you can just take the next one and you'll be fine. You can always call a pharmacy too, they'll answer your questions.
posted by spaghetti at 5:22 PM on February 11, 2005

nprigoda says it all on the dosage. Hypomanic episodes are definitely not fun.
posted by spaghetti at 5:24 PM on February 11, 2005

I take a really low dose of Zoloft daily, about 5 mg, and I fell draggy if I miss a dose. I find the low dose pretty effective, and doses above 12.5 mg/day gave me anxiety attacks. Anonymous, if you have weird side effects after missing a dose, call your doctor. See a specialist if you can't find a drug/dosage that works for you. Getting the correct meds/dosage can be difficult, but it's worth it.

I don't agree with xmutex, except that I hope someday we may realize that SSRIs were used like a sledgehammer; and we will likely have more effective remedies that are less drastic and more effective. Before SSRIs, there were a few drugs with limited effectiveness and serious side effects, and a lot of people really suffered. For me, SSRIs are a gift.
posted by theora55 at 6:03 PM on February 11, 2005 [1 favorite]

I think spaghetti has the best idea. Questions like this one should be addressed to your local pharmacist. They go to school for multiple years just so that they can answer these sort of questions.
posted by nprigoda at 6:07 PM on February 11, 2005

I've heard the "zaps" referred to as "brain shivers" on all sorts of message boards dealing with depression/anxiety meds.

Yes! That's as good a description as I've heard.

This whole thread is a great testimony re: why to avoid SSRIs at all costs.

Needless to say, I disagree. Like most things, it's a cost/benefit analysis. If the benefit's big enough, almost any cost is worth it.
posted by pardonyou? at 6:17 PM on February 11, 2005 [1 favorite]

I disagree as well, for me the benefits more than outweigh the withdrawal problems. For people with severe depression, it's a godsend.
posted by lilboo at 7:58 PM on February 11, 2005 [1 favorite]

When I was on Zoloft and/or Prozac (i.e., maybe it happened with both, but I'm not sure), I would feel like utter crap if I missed a morning's dose. Basically, for that day, I would feel as bad as I had before I was on the medication. It was odd, because everyone said that it was supposed to have a really long half-life. I thought it might just be psychological (well, y'know...), but I sometimes I only realized I had missed a dose because my horrid mood got me thinking about it.
posted by whatnotever at 9:12 PM on February 11, 2005

Question: given its long half-life, how can going off Prozac for a couple of days have any effect?

While it's true that traces of Prozac stay in your system a long time, there is a difference between how long it lasts and how long it is at its peak efficacy for. IIRC, that point is somewhere around 6-8 hours after ingestion. Side effects etc will also change based on this.

That being said, I personally experience no adverse effects from missing a dose, and I'm on one big motherfucking dose of Prozac.
posted by purtek at 9:43 PM on February 11, 2005

First off, disclaimer: I am not a psychiatrist nor do I claim to be. What I am is someone who has struggled with an extremely severe case of bipolar disorder type I (the manic variety) for 8 years, going through many, many medications in that time. Furthermore, my wife (herself a bipolar type 2 - the depressive variety) is a moderator for an online bipolar support group with 15,000 members. Between the two of us and our friends we've had a lot of anecdotal, first and secondhand experience with just about every drug under the sun.

Addressing the original question: if you miss a dose don't worry about it. Unless the packaging or your doctor say differently, if you still have 12 hours until your next dose then generally speaking you'll be fine taking it late. If you have less than 12 hours, just skip it and don't worry about it.


Sorry for the caps, but that point needed to be conveyed. A manic episode, speaking as someone who used to experience them weekly, is not something you ever want to have and a solid jump in the amount of SSRIs you're taking. Beyond mania there is psychosis, which I've only experienced once - in my case, in addition to the whole talking to non-existent people thing, blood started pouring out of the walls, then demons came flying screaming out of said walls and I could see, hear, smell, and feel said demons tackle and eviscerate me (according to my parents I was rolling on the floor screaming bloody murder).

Taking too much SSRIs can lead to hypomania - which speaking from personal experience can actually be kind of pleasant once you get used to it (similar to taking ephedra) but generally not a good way to live, mania - generally involving screaming delusions of grandeur, blowing wads of cash on frivolous crap, and rampant destruction of property or personal relationships, and in extreme cases psychosis - which is difficult for normal people to attain unless you're a bipolar misdiagnosed as depressive by a sloppy p-doc and taking large doses of SSRIs (*ahem*).

The SSRI's have very, very different half-lives. In general, the withdrawl feelings are worst with Effexor, Paxil, and best/nonexistent w/ Prozac. Dosing and an individual's metabolism matter a lot.

Spot on. One final note here - unless like lilboo absolutely nothing else works for you, I cannot suggest strongly enough that you avoid Paxil like the plague. While there is little to nothing in the way of peer-reviewed studies regarding it being especially harmful, my wife and I have certainly noticed an endless torrent of anecdotal evidence regarding friends, acquaintances, people in support groups who have taken Paxil and been permanently psychologically damaged by it. If you can, I'd suggest avoiding it in favor of something else.
posted by Ryvar at 12:22 AM on February 12, 2005

A suggestion: after years of worrying "did I take my meds today?," I bought two cheap seven-day pillboxes (a.m. and p.m.). No more worries.
posted by Carol Anne at 4:19 AM on February 12, 2005

Paxil, 20mg once per day. If I go more than ~36 without a dose, then I get mild zaps and accompanying mini-bouts of vertigo.

The answer: don't miss a dose! My life is much, much more better WITH the meds than without them.
posted by davidmsc at 8:41 AM on February 12, 2005

Ryvar, isn't Effexor being found to be akin to Paxil, ie. permanently damaging?

Also: geez, there are a lot of us on SSRIs. WTF? Have we all had bouts of black, gooey, suicidal depression?

That's a little alarming if true.
posted by five fresh fish at 9:37 AM on February 12, 2005

FFF: If it is, I've yet to hear of it. Paxil is the brand name for paroxetine which is an SSRI (Selective Serotonin Reuptake Inhibitor), wheras Effexor is the brand name for venlafaxine which is an SNRI (Serotonin/Norepinephrine Reuptake Inhibitor).

They're two different drugs made by two different companies with two different purposes. Effexor doesn't have as negative a reputation as Paxil by a longshot. Paxil has been known to induce spontaneous, extreme bouts of anger in people actively taking it. Withdrawl symptoms are so severe that there have been several suits against Glaxo Smith Kline by people who are simply unable to stop taking it. Finally, there is quite a lot of anecdotal evidence floating around online support groups of Paxil permanently leaving you feeling doped up or zombielike after you stop taking it. Effexor has been known to have some odd side effects in terms of mood while taking it, but they're not ragelike and if it has caused permanent damage in anyone after they stopped taking it, my wife and I have yet to hear about it.

Paxil is just a terrible drug, frankly, and I have a few friends who have been mentally scarred by it. I highly suggest that anyone who can avoid it do so.
posted by Ryvar at 10:02 AM on February 12, 2005

I'm on 10mg of Celexa a day and was previously taking 20mg a day. On both doses I've missed one day and didn't have any problems. I've also missed single doses of Wellbutrin (150mg - not sure if it's an SSRI) without problems.

xmutex: If we all avoided SSRI's there would sure be a bunch of bridge abutments to be cleaned up. Not a pleasant thought.

FFFish: I've said the same thing. Maybe it's all Mathowie's fault. Kidding, just kidding!

This may be inappropriate in this thread and if so, please delete: The smaller doses of Celexa aren't very effective and will have to try something new or re-up my dose size (was lowered due to daily headaches, headaches are still happening 3-4 times per week). Doc mentioned Effexor last time. Any other recommendations?
posted by deborah at 10:45 AM on February 12, 2005 [1 favorite]

I could have sworn I heard that Effexor created permanent brain changes after withdrawal.
Deb, I've been on 20 and 30mg Celexa for the past several years. I accidently double-dosed one morning this darkest December and noticed a distinct mood elevation, such that I recognized that I'd been operating in a depressive mode (SAD-induced, I expect). I experimented with upping the dosage for a week and got excellent results, reduced the dosage back to its original for a week, and then went to my doctor and asked for a represcription.

So far, things have remained good. As the days start getting brighter and I start riding motorcycle again, I'll try a lower dosage once again. The difficulty, as always, will be in recognizing the signs of early depression long before it becomes an issue.
My experience with Effexor was interesting to say the least. For the first few months I experienced the trippiest, acid-like symptoms: the earth would shift while my head did not, or would lag behind my head movements; I had vivid and surreal dreams; I got zaps and twinklies and spins; etcetera. Coming off it was equally trippy. It would easily have been disturbingly freaky if I hadn't decided to enjoy it as amusing and interesting, if somewhat tiresome.

I had nothing at all like that with Celexa.
posted by five fresh fish at 11:16 AM on February 12, 2005

FFF, you may be thinking of this, plus a severe and drawn out withdrawal does appear to be a problem that's recognised by doctors.

My own experience with Effexor was very limited: after three days it had dropped my blood pressure so low I'd faint if I stood up quickly, so that was the end of that. I found the horror stories when I subsequently went looking to see if anyone else had suffered a similar effect and ended up feeling very glad I wasn't going to continue taking it.
posted by arc at 12:49 PM on February 12, 2005

Thanks, arc! That's exactly the sort of thing I'd heard:
But the most disturbing freaky rare side effect with Effexor (venlafaxine hydrochloride) is what Wyeth disingenuously calls "withdrawal syndrome," that once you acclimate to Effexor (venlafaxine hydrochloride) you are basically hooked for life. The discontinuation syndrome never goes away if you try to stop.
In other words, you get the zaps for life.

That said, it goes on to state:
As for unipolar depression, if you're in the blackest pit of despair and your doctor recommends Effexor (venlafaxine hydrochloride), go for it. What? You don't think I care about you people? I do. For people with unipolar depression a lifelong addiction to Effexor (again, this is a very rare side effect) is just a pain in the ass.
Approach with caution would be my recommendation.
posted by five fresh fish at 2:39 PM on February 12, 2005

Also, cool site. Very amusing while also practical.
posted by five fresh fish at 2:42 PM on February 12, 2005

Most of the SSRIs, including paroxetine/Paxil, sertraline/Zoloft, fluvoxamine/Luvox, citalopram/Celexa, and escitalopram/Lexapro, have half lives on the order of a day, maybe 32 hours for escitalopram and 16 hours for fluvoxamine.

Fluoxetine/Prozac is unusual in that it has a two-day half life and a (slighty less-) active metabolite with a 9 day half life. Venlafaxine/Effexor is unusual in the other direction; its half life is 5 hours and that of its active metabolite is 11 hours.

I tell my patients if they miss a dose and not more than a day has gone by, just double it up, with the exception of venlafaxine, which I don't use.

The most interesting parallel to the venlafaxine 'off' syndrome, whatever it is, is that of L-DOPA in Parkinson's disease patients. Basically L-DOPA creates a burst of dopamine, a monoamine that is similar to serotonin in chemical structure but which is important in regulating things like the initiation of choreographed movemets like walking.

Prolonged administration of L-DOPA has pretty serious effects; the more that it's been used, the shorter the duration of action and the worse the withdrawal. L-DOPA withdrawal usually manifests with freezing, dystonias (cramps), unwanted movements (athetosis), and so on.

Now mood isn't like walking. Or maybe it is? I wonder if something similar isn't seen in patients who take these serotonin agonists. Still, reports of long discontinuation syndromes that are equivalent to depression need to be taken in context - these are people who were seriously depressed before they ever began treatment.

Bear in mind that when someone comes to my office, they are there because they want help with something. Although I'm a neurologist, in my inner city free practice I'd guess the real reason about 35% of the patients are there is that they're crippled by depression. The headaches and the backaches that they're referred for are not their main problem. The medicines are useful for me and for them in this context; particularly so where I have nothing else to offer.
posted by ikkyu2 at 3:23 PM on February 12, 2005

Thanks, FFfish and arc. I'm not sure what I'll go with, but at least I have more info for my appointment on Monday.
posted by deborah at 7:17 PM on February 12, 2005

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