Paxil vs. Prozac: Differences and Similarities

Depression and anxiety can have a significant negative impact on your daily life, and both are very common: About 40 million American adults suffer from an anxiety disorder, and more than 16 million are suffering from major depressive disorder, or MDD.

Most of those suffering—more than 60 percent—don’t seek treatment.

If you’re among that 60%, there are a number of medications approved by the U.S. Food and Drug Administration (FDA) that can help treat these disorders and improve your quality of life.

Your doctor or healthcare provider can work with you to find a medication that will work best for your symptoms.

But antidepressants often involve some trial and error. It can take some time to find the right prescription for your symptoms.

Two of the most popular antidepressant options are Paroxetine (Paxil) and fluoxetine (Prozac).

Both are a type of antidepressant called selective serotonin reuptake inhibitors, or SSRIs.

SSRIs are often considered the first-line treatment for depression and anxiety by healthcare providers. 

If you’re considering Paxil or Prozac to help with your symptoms, it’s important to consider the unique uses and possible side effects for each.

In this article, I’ll describe the differences and similarities between these two medications, the side effects of both, as well as some precautions and warnings for starting any new antidepressant.

Paxil vs. Prozac

Paxil and Prozac are FDA-approved SSRIs antidepressant medications that affect mood by increasing the levels of a chemical called serotonin in your brain. 

Serotonin is a neurotransmitter, a type of chemical used to transmit messages by your brain and body.

When serotonin is present in the brain, it can promote feelings of calm and a better mood.

Under normal conditions, when serotonin finishes carrying its message, it is reabsorbed by the brain, a process called “reuptake.”

People who recycle serotonin too quickly may experience symptoms of depression.

SSRIs interrupt the reuptake process so that more serotonin is available in the brain, which can alleviate symptoms. 

Conditions treated by both

Paxil and Prozac can both be prescribed to treat:

• Major depressive disorder (MDD): MDD is sometimes called clinical depression. The most common symptom is a constant feeling of sadness or hopelessness. Additional symptoms can be present too, including feeling empty or tearful, tiredness, loss of interest in previously enjoyed activities or hobbies, and suicidal thoughts. MDD is most prevalent in people between the ages of 18-25, but anyone can suffer from this disorder. 

• Obsessive compulsive disorder (OCD): OCD is a common disorder marked by repetitive, unwanted, or uncontrollable obsessions and compulsions. Obsessions are intrusive thoughts that won’t go away—such as fear, obsession with cleanliness or order, or unwanted sexual thoughts. People with OCD feel that they must perform certain behaviors in order to suppress or ease these anxious thoughts and feelings. These behaviors are called compulsions, and can include repeatedly opening and closing doors, sanitizing surfaces, turning lights on and off, or counting objects. In most cases, these obsessions and compulsions make it difficult for the person to fulfill other daily tasks and responsibilities.

• Panic disorder: Panic disorder is an anxiety disorder that is marked by sudden episodes of intense anxiety and fear accompanied by physical symptoms, including chest pain, shortness of breath, heart palpitations, dizziness, and abdominal stress. These episodes occur repeatedly, and are not in response to a known fear or stressor.

• Premenstrual dysphoric disorder (PMDD): PMDD is a severe form of premenstrual syndrome (PMS). Symptoms of PMDD also occur earlier and last longer than PMS, usually beginning in the week before menstruation and continuing until a few days after the menstrual period begins. People with PMDD can experience both psychological and physical symptoms, most notably irritability, nervousness, insomnia, anxiety, forgetfulness, difficulty concentrating, abdominal cramps, bloating, constipation, nausea, backache, acne, vision changes, food cravings, and diminished sex drive.

Which is more effective?

The FDA has approved both Paxil and Prozac for the treatment of clinical depression and other conditions.

The effectiveness of one or the other will vary depending on the individual and their circumstances, including their medical history, genetics, and more. 

In one clinical trial, researchers found no significant difference between Paxil and Prozac in the treatment of anxious depression—both were effective.

Another trial comparing benefits of the medications in patients with non-anxious depression also found both medications to be equally effective. 

How is each taken?

Both Paxil and Prozac are available as a liquid, and in immediate-release and long-acting (extended-release) tablet forms.

Both are usually taken once a day, and can be taken with or without food.

Providers often recommend taking these medications with food to avoid an upset stomach. 

The optimal dose of Paxil or Prozac will vary depending on your medical history and condition.

For MDD, Paxil dosage ranges between 20-50 mg per day.

Prozac dosage for MDD is between 20-60 mg per day.

When taking a prescription antidepressant, take the medication at the same time every day.

Follow the instructions laid out by your provider and pharmacist.

If you miss a dose, take the missed dose as soon as possible, unless it’s time for your next dose.

In that case, skip the missed dose. Do not take two doses at once to catch up.

Never stop taking Paxil, Prozac, or any other antidepressant suddenly.

If you do, you may experience withdrawal symptoms.

These symptoms can include headache, dizziness, anxiety, and irritability.

To taper off of your medication safely, talk to your doctor or a healthcare professional. 

Paxil vs. Prozac Side Effects

The most common side effects of Paxil and Prozac are usually mild, and resolve on their own as your body adjusts to the medication.

If you experience severe or persistent side effects, contact your doctor.

Side effects of Paxil

Some of the most common side effects with Paxil are:

• Vision changes
• Weakness
• Dizziness
• Fatigue
• Sweating
• Anxiety
• Shaking
• Insomnia
• Loss of appetite
• Vomiting
• Dry mouth
• Diarrhea or constipation
• Headaches
• Sexual dysfunction (including a decrease in sex drive, impotence, difficulty ejaculating, or difficulty reaching orgasm)

Side effects of Prozac

Some of the most common side effects with Prozac are:

• Insomnia or strange dreams
• Headache
• Dizziness
• Vision changes
• Tremors or shaking
• Worsened feelings of anxiety or nervousness
• Fatigue
• Pain
• Weakness
• Indigestion
• Dry mouth
• Sweating or hot flashes
• Changes in appetite
• Changes in weight (weight loss is especially common in children)
• Stuffy nose or other flu-like symptoms
• Sexual side effects, including decreased sex drive, impotence, or trouble reaching orgasm

Major Differences Between the Two SSRIs

Paxil and Prozac are both SSRIs, and can be used to treat many of the same conditions.

But they are not the same. The major differences between them include: 

• Use in children: Paxil is only FDA-approved to adults aged 18 years and older, but Prozac is approved to treat adults and children (aged 8 and older).

• Cost: Generic forms of both Paxil and Prozac can be purchased at similar prices, but purchasing the brand name of Paxil may be slightly more expensive than the brand name of Prozac.

• Conditions treated: In addition to their shared uses, Prozac can also be prescribed in the treatment of bulimia nervosa, an eating disorder. Paxil is also approved to treat generalized anxiety disorder (GAD), social anxiety disorder (SAD), and post-traumatic stress disorder (PTSD). Prozac may be prescribed for SAD and PTSD, but this is off-label.

Precautions and Warnings Before Taking Either

In addition to mild side effects that can occur, some rare but severe side effects are also possible when taking either medication, including suicidal ideation or suicidal thoughts. 

Tell your doctor or healthcare provider about any existing medical conditions you have, medications or supplements you’re currently taking, and whether or not you’re pregnant or plan to become pregnant. 

In general, you should be mindful about your alcohol intake when using Paxil or Prozac, as excessive alcohol drinking can cause drowsiness and may make the medications less effective.

If you are prescribed either medication and still want to drink alcohol, talk to your doctor first.  

When to See a Doctor

If you’re experiencing symptoms of depression, panic disorder, OCD, PMDD, or another mental health condition, reach out to your doctor or healthcare provider to see if an SSRI or alternative treatment option may help.

Once you’ve started an SSRI, talk to your doctor if the medication isn’t working, or if you’re experiencing troublesome side effects, including suicidal ideation.

Seek medical attention if you experience any of these rare, but serious side effects:

• Severe dizziness
• Hives, or a red or purple rash with blistering or peeling
• Itching or swelling, particularly of the mouth, face, or throat
• Difficulty breathing
• Seizure
• Abnormal bleeding or bruising

Seek medical care if you experience any of the following signs of an overdose:

• Unsteadiness
• Confusion
• Unresponsiveness
• Nervousness
• Uncontrollable shaking
• Rapid, pounding, or irregular heartbeat
• Hallucinations
• Fainting

How K Health Can Help

Think you might need a prescription for Prozac (fluoxetine) or a prescription for Paxil (paroxetine)?

K Health has clinicians standing by 24/7 to evaluate your symptoms and determine which prescription is right for you.

Get started with our free assessment, which will tell you in minutes if treatment could be a good fit. If yes, we’ll connect you right to a clinician who can prescribe medication and have it shipped right to your door.