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Possible Discontinuation Reaction from Serotonin Reuptake Inhibition


Any of the following medications can cause a "discontinuation reaction" if abruptly stopped, or if the dose is rapidly reduced.

  • Celexa (citalopram)
  • Cymbalta (duloxetine)
  • Effexor and Effexor-XR (venlafaxine)
  • Lexapro (escitalopram)
  • Luvox (fluvoxamine)
  • Paxil and Paxil-CR plus generic formulations (paroxetine)
  • Prozac (fluoxetine)
  • Zoloft (sertraline)

The good news is that it is not dangerous, but the bad news is that it can be quite unpleasant. Fortunately it is easily avoided, or it can quickly be addressed if intervention begins with the first signs of its emergence.

Why Does a Discontinuation Reaction Occur?

The discontinuation reaction usually does not occur until someone has been on one of these medications for about four to six weeks or longer. By way of analogy, imagine leaning on a friend and your friend suddenly moves. You will quickly be trying to not fall over and lose your balance. In similar fashion, your body has made an adjustment to the presence of the medication, and if you abruptly stop it, the blood level of the medication comes down very quickly and your system is out of balance.

Not everyone experiences this, but up to 20-25% will, with it being more commonly encountered with Paxil (paroxetine) and Effexor (venlafaxine) products. Because Prozac (fluoxetine) eases itself out of your system very slowly, it is less likely to cause any discontinuation symptoms.

What are the Symptoms?

If symptoms are going to emerge, most invariably they begin within 24 to 72 hours of no medication, or after a significant reduction in the medication dosage. If someone goes 72 hours without symptoms, then they probably will have no discontinuation problems. If they do have problems, the first symptoms are usually complaints of feeling light-headed, dizzy, spacey, or "weird in the head." If you soon take a dose, the blood level is back up in 1½ to 2 hours and the symptoms soon resolve. If not, the discontinuation reaction may progress... still not dangerous, but potentially a lot more unpleasant.

The two categories of ensuing symptoms are neurological ones and flu-like ones.

  • In the first category, complaints range from numbness and tingling to brief electric shock sensations occurring intermittently in arms or legs.
  • More common is the latter category; appearance of flu-like symptoms (headache, dizziness, sinus congestion, nausea infrequently accompanied by vomiting, abdominal discomfort, diarrhea, muscles aching, joint pain, insomnia, restlessness, malaise, and fatigue, but no fever and no immune system response). Any or all of these may occur, and to varying degrees. Once such symptoms are underway, resumption of the medication may not stop its course; at this point only time will heal. It resolves on its own in 1 to 2 weeks.

How Can This Reaction be Prevented?

Again, it is not dangerous; but who wants to feel bad unnecessarily for such an extended period of time?

  • If you frequently go out of town for the weekend, put three days of medication in your overnight bag.
  • If you tend to run out of medication before seeking a refill, keep a three day supply in a separate bottle so that when your main supply runs out, you now have three days to contact your prescriber or to pick up an available refill at your pharmacy.
  • If it has been determined that it is a good time for you to be stopping your medication, ask your prescriber for instructions as to how to best do so.