Paroxetine (Paxil): Uses, Dosage & Side Effects

Paroxetine, commonly sold under the brand names Paxil®, Brisdelle® and Pexeva®, is used to treat various mental health disorders. This includes major depressive disorder (MDD), generalized anxiety disorder (GAD), obsessive-compulsive disorder (OCD) and social anxiety disorder.

As with any medication, dosages vary depending on what you’re taking it for, and there’s always a risk of side effects.

Read on to find out how Paxil works, the dosages, the side effects and everything else you need to know about this prescription drug.

What Is Paroxetine Used For?

While medical professionals commonly prescribe paroxetine to adults with depression, the U.S. Food and Drug Administration (FDA) has also approved it to treat:

• Generalized anxiety disorder (GAD)

• Obsessive-compulsive disorder (OCD)

• Social anxiety disorder

• Post-traumatic stress disorder (PTSD)

• Panic disorder

• Premenstrual dysphoric disorder (PMDD)

• Menopause-related hot flashes and night sweats

Doctors sometimes prescribe paroxetine off-label (for reasons other than its FDA-approved uses) to treat:

• OCD in kids and teens

• Social anxiety disorder in kids and teens

• Separation anxiety

• Body dysmorphic disorder

• Postpartum depression

How Does Paxil Work?

SSRIs like Paxil and Paxil CR act on neurons that produce serotonin — a mood-regulating neurotransmitter and hormone sometimes known as the “happy chemical.”

Let’s unpack that mechanism of action.

Basically, SSRIs work by blocking the reuptake of serotonin by serotonin-producing neurons in your brain. Your brain produces serotonin naturally, but some people’s neurons reabsorb it quicker than others, leading to lower levels of active serotonin.

Feeling down? Low serotonin activity might be to blame, according to research. SSRIs can help improve your mood by stopping your neurons from reabsorbing serotonin too quickly.

How Long Does Paxil Take to Work?

Curious about how long Paxil will take to produce effects? There’s no one-size-fits-all answer. The timeline varies based on the reason you’re taking it, your dosage, and how your body reacts to the medication.

According to the National Alliance on Mental Health, you might notice improvements in your sleep, energy, and appetite within the first one to two weeks. However, it can take six to eight weeks for symptoms like low mood and lack of interest in activities to fully improve.

In short, give it a few weeks to feel the full effects of Paxil. Patience is key.

Paxil Dosages

Paroxetine dosages vary based on your specific needs. Your healthcare provider will determine the right dosage for you, but here’s a rough idea of what to expect:

• Depression. If you’re taking Paxil for depression, the recommended starting dose for an immediate-release formula is 20 milligrams (mg). This is the right dose for many people, but your provider might increase this by 10 mg each week, depending on how you respond to the drug, up to a maximum of 50 mg.

• Anxiety. If you’re taking Paxil for anxiety, a starting dose could be 20 mg per day. Your provider may increase this dose by 10 mg per day at weekly intervals, up to 50 mg per day. For most people, though, 20 mg will be the best target dose.

• Social anxiety disorder. The recommended starting/target dose for social anxiety is also 20 mg per day.

• Panic disorder. For panic disorder, the recommended starting dose is 10 mg, with a target of 20 mg, and a max of 50 mg.

• OCD. For OCD, you might get started on a dose of 20 mg a day. This could increase by 10 mg at weekly intervals, with a maximum of up to 50 mg a day.

• PMDD and Menopause symptoms. For premenstrual dysphoric disorder and menopause hot flashes, your provider might prefer the controlled release formulation, prescribing a lower dose of 12.5 mg and 7.5 mg, respectively, daily to start.

• PTSD. The starting/target dose for PTSD is 20 mg daily, and the recommended max is 50 mg.

Your dosage might also depend on whether you’re taking controlled-release or immediate-release medication. And it may vary for older adults and people with kidney or liver problems.

How to Take Paxil

No matter your dosage, you’ll typically take a single daily dose of Paxil, with or without food.

But is the best time to take paroxetine in the morning or night? According to the FDA, morning is ideal.

Other scientific literature suggests you can take it any time of day. It really comes down to what works best for you. You might find it easier to manage side effects in the morning, for example.  Some people, though, experience mild sleepiness with Paxil. For them, bedtime is the best time to take it.

Learn more about taking Paxil in our Paxil dosage guide.

Side Effects of Paxil

Like all medications, Paxil comes with a potential risk of side effects.

Common paroxetine side effects include:

• Weakness

• Constipation

• Diarrhea

• Nausea

• Dizziness

• Dry mouth

• Insomnia

• Drowsiness

• Sweating

• Tremor

• Blurred vision

• Lowered appetite

Although decreased appetite can cause weight loss, people have also reported weight gain as a side effect of taking Paxil.

SSRIs — including Paxil — can also mess with your sex drive. Common sexual side effects include:

• Decreased libido (interest in sex)

• Trouble reaching orgasm

• Erectile dysfunction

Uncommon side effects of paroxetine include:

• Weird or particularly vivid dreams

• Rash

• Muscle pain

• Electric shooting sensations

• Heart palpitations

• Feeling flushed

• Tingling sensations

• Muscle twitching

• Manic mood

• Aggressive or suicidal thoughts

Drugs affect everyone differently, so there’s no universal list of Paxil first-week side effects. Some people may notice side effects early on, but these usually fade within a week or two as your body adjusts.

If sexual side effects persist, speak with a healthcare professional for solutions.

Be cautious about stopping paroxetine abruptly. Discontinuation syndrome — the withdrawal symptoms you might experience when you suddenly stop taking antidepressants — is more common and can be more severe with paroxetine than other SSRIs.

This is likely because Paxil has a short half-life of about 21 hours, meaning the drug exits your body faster than other SSRIs.

Possible effects of suddenly stopping paroxetine can include:

• Nausea

• Sweating

• Anxiety

• Trouble sleeping

• Tiredness

• Electric shock sensations

If you want to stop taking Paxil, speak to your provider. They can help you safely discontinue the medication by gradually reducing your dose.

Paxil Drug Interactions

Here are some important paroxetine interactions to be aware of.

Avoid taking Paxil if you’re using monoamine oxidase inhibitors (MAOIs). This class of antidepressant medication is rarely used these days, but in the unlikely event you were prescribed an MAOI, make sure there’s a 14-day gap between stopping an MAOI and starting Paxil. MAOIs include:

• Isocarboxazid

• Linezolid

• Methylene blue

• Phenelzine

• Selegiline

• Tranylcypromine

Both Paxil and MAOIs influence the amount of serotonin in your system, so mixing the two can increase your risk of serotonin syndrome, a potentially life-threatening condition.

Some signs of serotonin syndrome include:

• Unstable blood pressure

• Dizziness

• Muscle tremors and rigidity

• Vomiting

Your risk of experiencing serotonin syndrome can also increase if you take Paxil with:

• Opioids

• Tricyclic antidepressants (TCAs)

• Triptans

• Lithium

• Tramadol

• Tryptophan

• Buspirone

• Amphetamines

• St John’s Wort

Paxil can also interact with pimozide and thioridazine, leading to a heart problem known as QT prolongation.

Additionally, mixing Paxil with NSAIDs like aspirin or ibuprofen and blood thinners like warfarin can increase your risk of bleeding events. Think nosebleeds, gastrointestinal (GI) bleeding, and hemorrhages.

You also shouldn’t take Paxil if you’re on tamoxifen to prevent breast cancer recurrence. The combination can decrease the effectiveness of tamoxifen and lead to an increased risk of breast cancer death. Let your doctor know if you have a family history of breast cancer. They may recommend another type of antidepressant.

Another tip: Steer clear of mixing Paxil and alcohol. Alcohol can reduce Paxil’s effectiveness and increase the risk of side effects.

Ultimately,  it’s always a good idea to let your provider know about any and all medications and supplements you’re taking to avoid potentially harmful combinations.

Paroxetine and Pregnancy

Paroxetine has a category D rating, meaning there’s evidence of risk to the fetus.

The FDA warns that taking paroxetine during pregnancy can cause heart malformations in fetuses. So healthcare professionals generally advise against taking it while pregnant unless the benefits outweigh the risks.

If you’re pregnant or planning to become pregnant, inform your healthcare provider before you start taking paroxetine. And be sure to tell them if you become pregnant while on the medication.

You may want to avoid breastfeeding while taking paroxetine since trace amounts can pass into breast milk. If taking Paxil is essential for your mental health, talk to your doctor about the pros and cons.

See our guide to Paxil and pregnancy for more advice.

FDA Black Box Warning: Suicidal Thoughts and/or Behaviors

The FDA has issued a black box warning for paroxetine, highlighting an increased risk of suicidal thoughts and behaviors in kids, teens, and young adults (up to age 24) on antidepressants. This applies to all antidepressants.

While paroxetine isn’t FDA-approved for those under 18, healthcare professionals might prescribe it off-label for this age group.

If you’re looking after a young person taking paroxetine, keep an eye out for any behavioral changes, especially during the first few months of treatment or whenever their dosage changes.

Reach out to your healthcare provider or seek medical help if you notice:

• Aggressive behavior

• Worsening depression

• Restlessness

• Irritability

• Unusual mood changes

If you or someone you know is self-harming or expressing suicidal thoughts, call emergency services immediately. You can also get help from the Suicide and Crisis Lifeline at 988.

Alternatives to Paxil

While Paxil might be the right choice for some, there are other options worth considering. If you’re curious, here are some other antidepressants to explore:

• Other selective serotonin reuptake inhibitors (SSRIs). Paxil isn’t the only SSRI available. Other options include citalopram (Celexa®), escitalopram (Lexapro®), fluoxetine (Prozac®), and sertraline (Zoloft®).

• Serotonin-norepinephrine reuptake inhibitors (SNRIs). SNRIs are another class of antidepressants. Unlike SSRIs that only act on serotonin, they also act on the neurotransmitter, norepinephrine. Examples include desvenlafaxine (Pristiq®), duloxetine (Cymbalta®), and venlafaxine (Effexor®).

• Atypical antidepressants. Bupropion (Wellbutrin®) works by increasing the activity of dopamine and norepinephrine in the brain, two other neurotransmitters that play a role in mood regulation.

Bottom Line: Starting Treatment With Paroxetine (Paxil)

Paroxetine is generally considered a safe, effective, and well-tolerated medication. And it might be the right treatment option for you.

Here are key facts to know:

• Paroxetine can treat a variety of mental health conditions. These include depression, anxiety, OCD, PTSD, social anxiety disorder, and panic disorder.

• Dosages depend on why you’re taking paroxetine. Your healthcare provider may start you on one dose and increase it if your symptoms don’t go away completely on the starting dose.

• Paxil has potential side effects. Mild side effects like nausea and constipation usually go away as your body gets used to the medication. If you get sexual side effects, they tend to persist for as long as you continue taking the medication. More serious side effects like serotonin syndrome and suicidal thoughts are possible but they’re less common.

Want to learn whether paroxetine could be the right treatment for you? Connect with one of our online psychiatry professionals today.

A telehealth provider can also advise you on the best meds for your condition and the benefits of each, such as Paxil versus Prozac.