Missed doses symptoms

[byronhinson]

I’ve stupidly missed a lot of my 20mg citalopram over the past week and today I’ve been feeling really nauseous. Is this likely a withdrawal symptom and if I start taking my dose again tonight how quickly might it pass.

[nomorepanic]

Yup it is not a good idea to miss any doses.


It depends on the person to be honest.

[wcs2222]

Hi.
If you missed 3-4 doses in a week, then your symptoms do sound like withdrawal, especially if they were on consecutive days. Citalopram has a half-life of ~35 hours, so missing an occasional dose would not be as bad as missing back-to-back doses.

Hopefully, things will go back to normal after you get back on the daily dose, without getting startup side-effects again. Please let us know how it goes.

Also, consider reviewing your dosing routine to make sure it does not happen again. When I first started, I set daily reminders on my smartphone.

[byronhinson]

Thanks. Due to a holiday I ended up only taking abou 2 out of 7 days of doses. Never again if this is the outcome! Felt sick all day. Sometimes dizzy too. Took a dose a short while ago when I returned home.

[MyNameIsTerry]

Cit reaches steady state at just over 7 days which is very close to the standard pharmacokinetic rule (5x half life) so if you unbalance it, it may need a few days or more to rebalance in your blood plasma which can mean some side effects but not like a cold turkey as you don't unpick long term effects of these drugs in such a short time (hence why withdrawals may be protracted even though the drug has exited the body completely).

And remember that aside from the 35 hour half life, drugs aren't eliminated by the body in double a half life. Again, going by the standard rule it takes 5x the half life to get to <5% (under clinical sufficiency) and 7x for 100% elimination (but bare in mind these rules are a guide and differ by drug as well as the individual but in the case of Cit they seem to map closely to clinical evidence). At each half life it reduces by 50% of the remaining drug e.g. at 35 hours you have 50%, at 70 hours you have 25%, etc) and that is based on not taking another dose so where you add a new dose you are adding more from that new drug on to replenish it.

Being at 50% you may not feel a difference as with many meds with shorter half lives we are close to this before we take the next dose anyway. But dropping lower may be more noticeable and that's when those multiple days after start showing up symptoms.