Paxil (paroxetine) is a SSRI (Selective Serotonin Re-Uptake Inhibitor) indicated for the treatment of depression and is also used for anxiety disorders. The dosage range of Paxil is typically anywhere from 10 mg per day to 60 mg per day, depending on the individual and indication.

In terms of side effects, SSRI medication have comparable tolerability overall, but the specific ones are certainly associated with a higher or lower incidence of certain ones. Paxil for example, tends to cause more weight gain than Prozac. The risk of certain side effects is dose dependent, meaner higher doses can increase the chance of side effects.

The dose of Paxil in this may be too high, or was started too high, if side effects are evident and don't decrease over time. When side effects occur during treatment with an antidepressant like Paxil, the initial strategy is generally to lower the dose of the drug or change to an antidepressant that is not associated with that side effect or in a different class.

Before going into the usual side effects with SSRI, it is important to be aware of the possibility of a rare, but serious side effect known as serotonin syndrome.

Serotonin syndrome is a rare disorder that is caused by excess serotonin in the brain. It isn't generally associated with the use with one agent ( SSRI) and individuals are most at risk when using multiple agents that affect serototonin. Symptoms incldue:

  • Mood changes
  • Abdominal pain
  • Sweating
  • Hyperthermia
  • Mental status changes
  • Renal failure

If any of these symptoms occur, it is a medical emergency and the individual should seek treatment immediately. As mentioned above, serotonin syndrome is very unlikely with the use of a single agent, like Paxil, but is theoretically possible with very high doses.

Below, we discuss side effects of Paxil which occur relatively frequently.

Paxil Side Effects

The following side effects are associated with Paxil

  • Gastrointestinal problems
  • Restlessness and insomnia
  • Sexual side effects
  • Neurological effects
  • Weight fluctuations


The most common complaint when starting on any SSRI medications are GI effects, such as nausea and vomiting. Theses GI effects tend to disappear around week 2 to 3 of therapy.

Neurological Effects

One of the most common side effects, according to the package insert for Paxil, is somnolence, with nearly 20% of individuals experiencing it. Somnolence is a prolonged feeling of sleepiness or drowsiness and may explain the "glazed over" look with your husband. Higher doses of Paxil are associated with an increased risk of somnolence.

Paxil has also been reported to initially exacerbate headaches disorder but this tends to decrease over time. Although medications associated with movement disorders such akathisia (i.e. a feeling of inner restlessness).Somnolence, 20.8%

Restlessness & Insomnia

A feeling of restlessness, especially in the evening, is a common initial side effect of SSRI medications. Zoloft in particular can exacerbate current restlessness, and sleep disorders. These side effects often decrease with time. Starting at the lowest possible dose and increasing slowly to effect is the most prudent approach to avoid this side effect.

Sexual Side Effects

Sexual side effects can refer to anything from erectile dysfunction to anorgasmia (i.e. lack of orgasm). This side effect appears to be dose dependent and if it occurs, may not dissipate over time. A change in medication or a sexual performance drug may be necessary if sexual side effects occur.

What Is Too High Of A Dose Of Paxil?

As mentioned above, the usual dosage range of Paxil is 10 mg to 60 mg per day, depending on the indication.

It is usually best practice to start at a low dose of Paxil and increase by 10 mg every week or so to effect and based on tolerability. The side effects mentioned above could be indicative that too high of a dose is being used, especially if the side effects don't subside with continued use.