10 Paroxetine Side Effects You Should Know About - GoodRx (2024)

Paroxetine (Paxil) is a selective serotonin reuptake inhibitor (SSRI). It was first approved in 1992 to treat depression. And it has since been approved for other conditions, including different anxiety disorders. A lower-dose version (Brisdelle) is used to treat hot flashes during menopause.

Paroxetine is thought to work by boosting the amount of serotonin in your brain. Serotonin is a chemical involved in regulating mood. Compared to other SSRIs, paroxetine has the most potent effect on serotonin. But this potency sometimes comes with some side effects.

Paroxetine side effects at a glance

Many paroxetine side effects are relatively mild and get better over time. More serious side effects are possible but are less common.

Common paroxetine side effects, many of which start in the first week of treatment, can include:

• Weakness

• Constipation

• Nausea

• Reduced appetite

• Diarrhea

• Dizziness

• Dry mouth

• Sexual problems

• Insomnia

• Weight gain

• Nervousness

• Drowsiness

• Sweating

• Tremor

• Yawning

• Urination problems

Less common but potentially serious paroxetine side effects include:

• Serotonin syndrome

• Antidepressant discontinuation syndrome

• Increased risk of bleeding

• Low sodium levels

• Serious allergic reactions

• Suicidal thoughts and behaviors

Keep in mind that while these side effects are possible, they may not happen to you.

We cover what you should know about 10 paroxetine side effects below.

1. Nausea

Nausea is a common side effect of antidepressants — including paroxetine. Up to 1 in 4 people taking paroxetine during clinical trials reported nausea. And it’s more likely to happen with higher doses. But for many people, nausea usually improves over time as your body adjusts to the medication.

Paroxetine can be taken with or without food. If you’re feeling nauseous after your dose, try taking it with food. Temporarily eating smaller meals and bland foods may also help while you’re feeling nauseous.

But if your nausea is interfering with your daily life or doesn’t go away, talk to your healthcare provider. They can help you lower your dose or switch you to a different medication. For example, extended-release (ER) paroxetine may cause less nausea for some people.

2. Drowsiness

It’s not unusual for antidepressants to make you feel drowsy. And among the different SSRIs, paroxetine seems to cause the most drowsiness. But this usually goes away after a few weeks of taking the medication.

Avoid driving or doing other tasks that require you to be alert until you see how paroxetine affects you. Let your healthcare provider know if your drowsiness doesn’t go away or gets worse. They may switch you to a different medication that’s less likely to make you drowsy.

3. Sleeping problems

Besides regulating mood, serotonin can also affect the areas of your brain that control sleep. So, it may come as no surprise that paroxetine can cause sleeping problems for some people. For example, you may have a harder time falling or staying asleep.

If you’re having trouble sleeping after starting paroxetine, ask your healthcare provider about taking your dose in the morning.

4. Sexual problems

Many people taking SSRIs experience sexual problems. These may include lower libido, trouble having an org*sm, or a delay in ejacul*tion. One theory is that serotonin can affect hormones and chemicals involved in sexual arousal and org*sm.

Paroxetine tends to have the highest rate of sexual problems among all SSRIs. Sometimes, this goes away after a few weeks. But this isn’t always the case.

Talk to your healthcare provider if sexual side effects don’t go away or become an issue at any point. They may add another medication to help limit these side effects. Or they may help you switch to an antidepressant that’s less likely to cause problems.

5. Weakness

Paroxetine can cause weakness, which may get better over time. But it can also be a sign of something more serious, including low sodium levels in your blood (called hyponatremia).

Older adults and people taking diuretics (water pills) have a higher risk of hyponatremia. And it tends to happen within the first 2 to 4 weeks of starting the medication.

Hyponatremia can be serious. If you develop weakness, let your healthcare provider know if it’s accompanied by headache, confusion, or feeling unsteady. This could be a sign your sodium levels are too low.

6. Weight gain

Studies suggest that paroxetine generally causes more weight gain than other SSRIs. But whether or not you gain weight — and how much you gain — varies by person. Weight gain is more likely to happen with higher doses or if you’re taking paroxetine for longer than 6 months.

If you’re concerned about gaining weight while taking paroxetine, talk to your healthcare provider. They can give you tips for how to maintain your weight and prevent possible fluctuations. This may include tracking your body weight and incorporating regular exercise into your routine.

7. Higher risk of bleeding

SSRIs like paroxetine can possibly raise the risk of bleeding. This risk may be higher if you’re taking paroxetine with other medications that also have bleeding risks. Examples include nonsteroidal anti-inflammatory drugs (NSAIDs) and blood thinners, like warfarin (Coumadin, Jantoven).

Let your healthcare provider know right away if you notice any new or unusual bruising, small purple or red spots on your skin, or other signs of bleeding.

8. Serotonin syndrome

Serotonin syndrome can happen when serotonin levels get too high in your brain. This isn’t common with paroxetine and other SSRIs, but severe cases can be life-threatening. Serotonin syndrome from paroxetine is more likely to happen if you’re taking higher doses or if you’re taking it with other medications and supplements that increase serotonin.

Mild symptoms include sweating, fast heart rate, and tremor (mild shaking in hands). More serious symptoms include uncontrollable body movements, confusion, and high fever. Let your healthcare provider know if you develop mild symptoms. If they become severe, get immediate medical help.

Also, make sure your healthcare provider and pharmacist have your current medication list. They can check for medications that could raise the risk of serotonin syndrome.

9. Antidepressant discontinuation syndrome

Don’t suddenly stop taking paroxetine — or lower your dose too quickly — on your own. You may start experiencing symptoms like headache, dizziness, and nausea. This is called antidepressant discontinuation syndrome. And it’s thought to be due to a sudden drop in serotonin.

Antidepressant discontinuation syndrome is temporary, but it can be unpleasant. To avoid it, don’t stop taking paroxetine or lower your dose without talking to your healthcare provider. They can help you safely — and slowly — taper off the medication.

10. Suicidal thoughts and behaviors

Paroxetine has a boxed warning (the FDA’s strictest warning) about the risk of suicidal thoughts and behaviors. This risk appears to be highest in people under 25 years old. All antidepressants carry this warning.

But everyone taking antidepressants should keep an eye out for suicidal thoughts and behaviors. This is especially the case after starting treatment and after dosage changes. Let your healthcare provider know right away if you notice changes in your mood or behavior.

When should I contact my healthcare provider about paroxetine side effects?

Many paroxetine side effects go away over time. But if they start interfering with your daily life, talk to your healthcare provider. They can help you lower your dose or switch you to a different medication.

We’ve covered a few serious paroxetine side effects above, including bleeding, serotonin syndrome, and suicidal thoughts and behavior. It’s important to talk with your healthcare provider right away if any of these occur.

That said, you don’t have to wait for a medical emergency to talk to your healthcare provider about side effects. Open communication with your healthcare team is key to making sure you find an antidepressant that works for you.

If you or someone you know is having thoughts of suicide, you’re not alone, and help is available. Call the National Suicide Prevention Lifeline at 988, or text HOME to 741-741 to reach the Crisis Text Line.