Switching Paxil (Paroxetine) From Night To Morning Dosing

Paxil can cause insomnia and is recommended for morning administration.


I am taking 20 mg of Paxil in the PM. What is the best way to switch to the AM? Thanks

Asked by Chuck On Aug 21, 2018

Answered by
Medical Content Reviewed By PharmacistAnswers Staff

On Aug 21, 2018

Morning Night IllustrationPaxil (paroxetine) is a selective serotonin reuptake inhibitor (SSRI) antidepressant. It is indicated for treatment in the following (1):

  • Major depressive disorder
  • Generalized anxiety disorder
  • Hot flashes
  • Menopause
  • Obsessive compulsive disorder
  • Panic disorder
  • Posttraumatic stress disorder
  • Premenstrual dysphoric disorder
  • Social anxiety

Recommended Time Of Day To Take Paxil

Many SSRI medications, including Paxil, are recommended to be taken in the morning as opposed to in the evening. Per the package insert for Paxil (1):

"PAXIL [paroxetine] should be administered as a single daily dose with or without food, usually in the morning."

The morning administration time recommendation for Paxil is due to the potential side effect of insomnia. Taking Paxil at night can cause difficult falling asleep and difficulty staying asleep. It has been reported that insomnia occurs in 8 to 24% of individuals on Paxil (2).

In fact, nearly all SSRI medications, which also includes includes Zoloft, Prozac, Celexa and Lexapro, are associated with sleep disturbances. Specifically, it has been reported that the SSRI class overall can cause (3, 4, 5):

  • Increased sleep onset latency
  • Increased number of awakenings
  • Overall decrease in sleep efficiency.
  • Suppression of REM sleep

In most cases, sleep related side effects will decrease the longer you are taking the medication. However, there are times where they won't completely subside which may necessitate a change in the time of day you take your medication or a change in medication entirely.

How To Change The Time You Take Paxil (Paroxetine)

For some individuals, switching Paxil to a morning administration time may help alleviate certain side effects, like insomnia. Unfortunately, there is no "recommended" way to change the time you take Paxil, or any SSRI for that matter, from nighttime to the morning.

For some drugs, it is extremely important to not miss, or allow too much time to pass between doses. Examples include antibiotics, anti-retrovirals and anti-Parkinson's drugs. Allowing too much time to elapse could potentially cause drug levels to fall too low, decreasing the efficacy of the medications. For the example of antibiotics, it could lead to your infection not being appropriately treated. In the case of anti-Parkinson's drugs, it could lead to a return or exacerbation of symptoms.

However, when it comes to antidepressants, in general, you don't want to double up, or take more than your usual dose in a 24 hours period (if you take one tablet daily) (1).

It is important to discuss with your doctor how to best adjust the time to earlier in the day. In most cases, they will recommend to:

  • Skip your usual nighttime dose and simply take your next dose at your desired time in the morning. This means that more than 24 hours will elapse between doses.

The good news regarding Paxil is that it stays in your body for an extended period of time due to its long half-life, around 21 hours (6). This means that it takes around 21 hours for drug levels to be reduced by 50% in your system. Paxil will still be in your system even after missing/skipping one dose.

In addition, consistent use of SSRI medication is thought to produce long-lasting changes to receptors in the brain and neurotransmitter release, which generally won't be much affected by one missed dose of Paxil (7, 8, 9).

As Paxil has a longer half-life (it will still be present in the body even after a missed dose), and the fact that SSRI use causes significant changes in the brain that aren't immediately reversed with one missed dose, it is unlikely changing your administration time on a one-time basis will have significant effects.

Nevertheless, as stated above, you should speak with your doctor regarding the best way to change the administration time of Paxil for your particular situation.

About the Pharmacist

Dr. Brian Staiger Pharm.D

Dr. Brian Staiger is a licensed pharmacist in New York State and the founder of PharmacistAnswers.com. He graduated from the University At Buffalo with a Doctor of Pharmacy degree in 2010. He has been featured in numerous publications including the Huffington Post as well as a variety of health and pharmacy-related blogs. Please feel free to reach out to him directly if you have any inquiries or want to connect! He's answered thousands of medication and pharmacy-related questions and he's ready to answer yours! Brian.Staiger@PharmacistAnswers.com Office: 716-389-3076

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