Paxil (Paroxetine) Side Effects: Common, Severe, & Rare

What Is Paxil (Paroxetine)?

Paxil (paroxetine) is FDA-approved for use in the treatment of depression, anxiety disorders, and other mental health conditions.¹ In some cases, the antidepressant may be prescribed  off-label for treating irritable bowel syndrome and obsessive compulsive disorder (OCD) in children.² Paxil is a selective serotonin reuptake inhibitor (SSRI) that works to regulate serotonin levels in the brain, a neurotransmitter that plays an important role in influencing one’s mood and emotions.

Paxil is among the most commonly prescribed antidepressants for treating major depressive disorder (MDD) and generalized anxiety disorder (GAD).^{3, 4} It can also be prescribed for obsessive compulsive disorder, panic disorder, social anxiety disorder, posttraumatic stress disorder, and premenstrual dysphoric disorder. Furthermore, Paxil has a well-established efficacy and tolerability profile. However, some studies suggest that the cholinergic muscarinic antagonism of Paxil may impact its tolerability.³

Side Effects of Paxil

Taking Paxil as a part of treatment can result in side effects which occur as the body adjusts to the medication. It is important to talk with your doctor about these risks in order to address safety concerns.

Common side effects of Paxil, such as nausea or headaches, typically emerge one to two weeks after an initial dosage.¹ However, in some cases, side effects can be severe and require immediate medical attention. The severity of one’s reaction depends on multiple factors, including their age, overall health, and the presence of other substances in their body. Mixing certain substances with Paxil can possibly result in overdose and sudden death.

Common Side Effects

Upon starting Paxil, a person is likely to experience side effects such as headaches or vomiting within the first week of their treatment. These effects will likely wear off within two to four weeks.

Common side effects of Paxil may include: ¹

• Headache
• Vomiting
• Nausea
• Drowsiness
• Dizziness
• Sleeping problems
• Restlessness
• Sexual problems
• Dry mouth
• Fatigue
• Weight changes
• Diarrhea or constipation
• Appetite issues
• Sweating
• Indigestion

Severe Side Effects

The severity of side effects may depend on how a person’s body adjusts to their medication, as well as their age and physical health. Additionally, combining Paxil with other medications or substances, such as alcohol, can lead to severe adverse reactions that can result in overdose, organ failure, or death.

Severe side effects of Paxil that may require immediate medical attention include¹

• Serotonin syndrome
• Manic episodes
• Increased bleeding
• Vision problems
• Irregular heartbeat
• Worsening anxiety symptoms
• Seizures
• Angle-closure glaucoma
• Discontinuation syndrome
• Hyponatremia
• Bone fracture
• Sexual dysfunction

Rare Side Effects

There are side effects of Paxil to be aware of that rarely occur, as these can be severe and require immediate medical attention. These can be more challenging to identify as they are uncommon and hard to detect during or following clinical trials. Therefore, it is important to discuss any adverse reactions to Paxil with your doctor.

Rare side effects of Paxil include:

• Fainting
• Stomach pain
• Muscle pain
• Poor coordination
• Shivering
• Difficulty speaking
• Pupil dilation
• Inability to move the eyes
• Electric shock sensations
• Swollen glands
• Swelling of the breasts

Allergic Reactions to Paroxetine

An allergic reaction to Paxil is possible, especially in people with a history of allergic reactions to other antidepressants. While severe reactions are rare, they can be severe and life-threatening. However, one can experience an allergic reaction to Paxil despite tolerating other medications well. Seek immediate medical assistance if you notice symptoms of a serious allergic reaction, including rash and dizziness.

Severe allergic reactions to Paxil may include:

• Difficulties breathing
• Swelling
• Rash
• Severe dizziness
• Itching

Long-Term Effects

Taking Paxil may lead to long-term and harmful complications. These are mainly influenced by pre-existing medical conditions or the interaction of Paxil with another substance such as alcohol. This can impact organs or result in memory problems. For example, taking Paxil while on blood thinners increases the risk of excessive bleeding.

Interactions With Paxil

Taking certain medications, herbs, or supplements alongside Paxil can change how Paxil works in your body or increase the risk for serious side effects. This article does not consider all the possible interactions. Please let your doctor, psychiatrists, and pharmacists know about all the products you currently use, such as prescription medication, nonprescription drugs, and herbal supplements. Do not start, stop, or change the dosage of Paxil or any medicines without your doctor’s approval.

Combining Paxil with other substances or medications can be life-threatening, as the main ingredients in Paxil can negatively interact with these substances. Furthermore, mixing Paxil with another substance may lead to worsening side effects of either substance.

Substances to avoid while taking Paxil include:¹

• MAOIs: Taking Paxil within 14 days of stopping MAOI treatment increases the risk of serotonin syndrome.
• Thioridazine: The interaction between Paxil and thioridazine increases the risk of serotonin syndrome.
• Pimozide: Interaction between Paxil and pimozide increases the risk of serotonin syndrome.
• Other SSRIs: Paxil combined with other SSRIs can only worsen the side effects of each substance.
• Amphetamines: Paxil may increase the effects of amphetamine such as racing thoughts, anxiety, and nervousness.
• Migraine medications: Mixing Paxil with migraine medications can raise serotonin levels in the body, increasing the risk of serotonin syndrome.
• NSAIDs: Combining Paxil with NSAIDs increases the risk of abnormal bleeding.
• Alcohol: The interaction between alcohol and Paxil can worsen the effects of either substance, and result in possible overdose.
• Blood thinners: Taking Paxil will interfere with the blood clotting process of blood thinners, increasing the risk of excessive bleeding.

This is not a comprehensive list of possible interactions with Paxil. You should talk with your doctor or pharmacist about all prescription or over-the-counter medications, herbs, or supplements that you take before starting Paxil.

Who Experiences Side Effects More?

The severity and frequency of side effects to any medication vary from person to person. This is attributed to several factors, including one’s age and how the drug interacts with their body. Also, certain health conditions, including bleeding problems, increases one’s risk for experiencing adverse reactions to Paxil. Talk with your doctor about your medical history before considering Paxil.

Discuss the risks of taking Paxil with a doctor if you have a history of or are currently:¹

• Pregnant or breastfeeding
• Eye problems
• Seizures
• Bipolar disorder
• Liver problems
• High blood pressure

Pregnant & Breastfeeding Individuals

Pregnant or breastfeeding individuals are discouraged from taking Paxil. Taking Paxil in the first trimester of pregnancy exposes an infant to the substance and may increase the risk of cardiovascular malfunctions. Paxil may also contaminate breast milk and expose an infant to the substance.¹

Older Adults & Children

Paxil may result in an increased risk of suicidal thoughts and behaviors in children. Additionally, older adults are more sensitive to the effects of Paroxetine, as they are more likely to have low sodium levels in the blood (hyponatremia). Therefore, vigilance and dosage adjustment for older populations is advised.¹

Paxil Withdrawal Symptoms

Paxil medication should be taken as prescribed by a doctor. However, if a person stops taking their medication for any reason, they put themselves at an increased risk for Paxil withdrawal, a condition that can be life-threatening. Symptoms include persistent headaches, increased sweating, and other adverse effects.

Long-term use of Paxil can lead to physiological dependence on the substance. This occurs after the body becomes accustomed to the presence of the substance. Paxil dependence can lead to substance misuse and worsening or reemerging side effects which can be harmful for your health. If you feel you are dependent on Paxil, discuss other medication options or a tapering dosage with your doctor.

Questions to Ask Your Health Team

Before starting Paxil, it is important to discuss and understand the risks associated with the medication. Your doctor will recommend the medication that is most suitable for you. This will ensure your physical health remains safe during treatment.

Questions to ask your care team about Paxil include:

• Are there risks involved with off-label Paxil treatment?
• How long will it take for me to adjust to Paxil?
• Am I at risk for more severe symptoms if I am taking other medications?
• Will a history of addiction make me more susceptible to dependency?
• When should I reach out to you about side effects?
• Should I tell my therapist that I am taking this medication?
• Why is pre-screening before taking Paxil important?
• How long do Paxil side effects last?
• How does Paxil compare to Prozac or other antidepressants?

Final Thoughts

Paxil is an effective medication for relieving symptoms of depression or anxiety. Taking the medication commonly results in mild side effects, but these may become severe depending on many factors. Because of this, discuss your concerns and medical history with your doctor honestly before considering this medication. If Paxil is not suitable for you, your physician can recommend an alternative.