Paroxetine hydrochloride (Paxil) is a prescription medication that is used to treat depression, obsessive-compulsive disorder (OCD), social anxiety disorder, and other conditions. The medicine belongs to a class of drugs known as selective serotonin reuptake inhibitors (SSRIs). Paroxetine works by blocking the reuptake of a chemical (serotonin) in the brain. The drug comes in tablet and suspension (liquid) form and is usually taken once a day. Examples of side effects that may occur include ejaculation problems, nausea, and insomnia.
Paroxetine is licensed to treat a number of conditions, including:
Depression (also known as major depression or clinical depression)
Obsessive-compulsive disorder (OCD)
Panic disorder
Social anxiety disorder
Generalized anxiety disorder (GAD)
Post-traumatic stress disorder (PTSD).
Paroxetine is part of a class of drugs called selective serotonin reuptake inhibitors, or SSRIs for short. SSRIs act on a specific chemical in the brain known as serotonin. Serotonin is one of several chemicals used to send messages from one nerve cell to another.
As a message travels down a nerve, it causes the end of the cell to release serotonin. The serotonin enters the gap between the first nerve cell and the one next to it. When enough serotonin reaches the second nerve cell, it activates receptors on the cell and the message continues on its way. The first cell then quickly absorbs any serotonin that remains in the gap between cells. This is called "reuptake".
Normally, this process works without any problems. But when the levels of serotonin become unbalanced, it can cause a variety of conditions, including depression. Paroxetine helps to block the reuptake of serotonin so more serotonin remains in the space between the brain's nerve cells. This gives the serotonin a better chance of activating the receptors on the next nerve cell.
Do not take paroxetine together with pimozide (Orap), thioridazine (Mellaril), linezolid (Zyvox), methylene blue (Urolene Blue), or a monoamine oxidase inhibitor (MAOI) such as furazolidone (Furoxone), isocarboxazid (Marplan), phenelzine (Nardil), rasagiline (Azilect), selegiline (Eldepryl, Emsam, Zelapar), or tranylcypromine (Parnate). A dangerous drug interaction could occur, leading to serious side effects.
Before you take paroxetine, tell your doctor if you have liver or kidney disease, a bleeding or blood clotting disorder, seizures, glaucoma, bipolar disorder, or a history of drug abuse or suicidal thoughts.
There are many other drugs that can interact with paroxetine. Tell your doctor about all medications you use. This includes prescription, over-the-counter, vitamin, and herbal products.
Paroxetine may cause harm to an unborn baby. Paroxetine may cause heart defects or serious lung problems in a newborn if you take the medication during pregnancy. Do not use Paroxetine if you are pregnant or plan to become pregnant.
You may have thoughts about suicide when you first start taking an antidepressant such as paroxetine, especially if you are younger than 24 years old. Your doctor will need to check you at regular visits for at least the first 12 weeks of treatment.
Report any new or worsening symptoms to your doctor, such as: mood or behavior changes, anxiety, panic attacks, trouble sleeping, or if you feel impulsive, irritable, agitated, hostile, aggressive, restless, hyperactive (mentally or physically), more depressed, or have thoughts about suicide or hurting yourself.
There have been several studies that looked at the effects of using paroxetine to treat various conditions.
Depression
Studies have shown paroxetine to be effective for depression treatment in adults. People taking it had more improvement in their depression symptoms, compared to those not taking it. Also, long-term studies have shown that it can help prevent relapse (when depression comes back).
OCD
In studies, up to 24 percent of adults with obsessive-compulsive disorder (OCD) who took paroxetine felt their OCD was "much improved," compared to only 11 percent of those who were not taking it. Only 3 to 7 percent of people taking it felt that their OCD was worse, compared to 14 percent of people not on paroxetine.
Panic Disorder
Two studies looked at using paroxetine to treat adults with panic disorder. Up to 76 percent of people taking paroxetine were free from panic attacks, compared to only 44 percent of those not taking it. Paroxetine has not been studied in children or teens with panic disorder.
Social Anxiety Disorder
In studies of paroxetine for social anxiety disorder, up to 77 percent of adults showed improvement while taking it, compared to only 42 percent of those not taking paroxetine.
Generalized Anxiety Disorder (GAD)
Studies have shown that more people with generalized anxiety disorder taking paroxetine have more improvement in their anxiety symptoms, compared to people not taking paroxetine. Also, long-term studies have shown that paroxetine can help prevent relapse (when anxiety comes back).
Post-Traumatic Stress Disorder (PTSD)
Studies have shown paroxetine to be effective for the treatment of PTSD in adults. More people taking it felt they were "much improved" or "very much improved," compared to people not taking it. Paroxetine was also shown to reduce PTSD symptoms.
Some general considerations for when and how to take the medication include the following:
It comes in tablet and suspension (liquid) form. You take the drug by mouth, usually once a day.
Make sure to shake paroxetine suspension well before each dose.
If the medicine makes you drowsy, try taking it before bedtime. If the medication causes insomnia for you, try taking it in the morning. Most people take it in the morning.
You can take it with or without food. If paroxetine bothers your stomach, try taking it with food.
Take paroxetine at the same time each day. This will help to maintain an even level of the drug in your blood.
For the medication to work properly, it must be taken as prescribed. The drug will not work if you stop taking it.
The dosage your healthcare provider recommends will vary depending on a number of factors, including:
Your age
The medical condition being treated
Other medical conditions you may have
Other medications you may be taking.
As is always the case, do not adjust your dose unless your healthcare provider specifically instructs you to do so.
In general, the recommended starting paroxetine dose is paroxetine 20 mg once daily (usually in the morning). However, the starting dose for treating panic disorder and for elderly people or people with liver or kidney problems is lower: paroxetine 10 mg once daily. Your healthcare provider may choose to increase the paroxetine dosage if symptoms continue, or decrease the dose if side effects occur.
The maximum paroxetine dose is 50 mg (for depression, generalized anxiety disorder, or post-traumatic stress disorder) or 60 mg (for social anxiety disorder, panic disorder, or obsessive-compulsive disorder).
As with any medicine, there are possible side effects with paroxetine hydrochloride (Paxil). However, not everyone who takes paroxetine will experience side effects. In fact, most people tolerate it well. When side effects do occur, in most cases they are minor and either require no treatment or can be easily treated by you or your healthcare provider.
(This article covers many, but not all, of the possible side effects with paroxetine. Your healthcare provider can discuss a more complete list of paroxetine side effects with you.)
There are a number of side effects of paroxetine that you should report to your healthcare provider, including, but not limited to:
Suicidal thoughts or behavior
Anxiety, agitation, or panic attacks
Hostility or aggressiveness
Engaging in unusual or dangerous activities
Extreme elation or feeling of happiness that may switch back and forth with a depressed or sad mood
Other unusual changes in behavior
Signs of serotonin syndrome (a rare but dangerous problem associated with certain medications), such as:
Confusion or other mental changes
A rapid heart rate
Nausea, vomiting, or diarrhea
Hallucinations
Blood pressure changes
An irregular heart rhythm
Overactive reflexes
Fever, sweating, or shivering
Shakiness
Agitation
Seizures
Coma
Chest palpitations
Easily broken bones
Difficulty sleeping
Feelings of internal restlessness or jitteriness
Signs of an allergic reaction, including unexplained rash, hives, itching, unexplained swelling, wheezing, or difficulty breathing or swallowing.
Paroxetine has been studied thoroughly in clinical trials in which the side effects of a group of people taking the drug are documented and compared to another group not taking the medicine. This way, it is possible to see what side effects occur, how often they appear, and how they compare to the group not taking the medicine.
In these studies, the most common side effects of paroxetine included:
Ejaculation problems -- occurring in up to 28 percent of people
Nausea -- up to 26 percent
Insomnia -- up to 24 percent
Drowsiness -- up to 24 percent
Weakness -- up to 22 percent
Dry mouth -- up to 18 percent
Headache -- up to 18 percent
Constipation -- up to 16 percent
Increased sweating -- up to 14 percent
Dizziness -- up to 14 percent
Diarrhea -- up to 12 percent
Shakiness (tremor) -- up to 11 percent.
Other common side effects (reported in 5 to 9 percent of people) include:
Loss of appetite
Nervousness
Impotence (erectile dysfunction or ED)
Infections
Agitation
Anxiety
Yawning
Painful menstrual cramps
Indigestion.
There are other possible paroxetine side effects that can occur. These rare side effects occur in 2 to 5 percent of people. Some of these side effects include, but are not limited to:
Abdominal pain (stomach pain)
Flushing (redness of the skin, especially the face)
Gas
Increased appetite
Muscle pain
Abnormal dreams
Trouble concentrating
Sore throat
Vision changes
Chest pain
Back pain
Personality changes
Muscle spasms
Runny or irritated nose
Bladder problems
Vomiting
Heartburn or indigestion (dyspepsia)
Feelings of a rapidly or forcefully beating heart (palpitations)
Memory loss (amnesia)
Taste changes.
Selective serotonin reuptake inhibitors (SSRIs), such as paroxetine, have been linked to decreased fertility in men. Apparently, the drugs may negatively affect sperm quality. It appears that this effect goes away once the drug is stopped.
It is possible that you may experience some or none of these paroxetine side effects explained above. Unfortunately, there is no way for your healthcare provider to know beforehand if you will have side effects from a medicine that you have never tried.
Therefore, make sure to let your healthcare provider know if you develop any side effects. Also, let your healthcare provider know if you develop something that "just does not seem right." While it may not be a side effect of paroxetine, your healthcare provider should be able to diagnose and treat the problem.
Paroxetine hydrochloride (Paxil) can potentially interact with a number of drugs. Some of the drugs that can lead to paroxetine interactions include:
Alcohol
Aspirin
Atomoxetine (Strattera)
Certain arrhythmia medications, including propafenone (Rythmol), flecainide (Tambocor), and quinidine
Certain seizure medications, including phenobarbital (Luminal) and phenytoin (Dilantin)
Cimetidine (Tagamet)
Digoxin (Digitek, Lanoxin)
Fentanyl (Abstral, Actiq, Duragesic, Fentora, Lazanda, Onsolis, Subsys)
Lithium (Eskalith, Lithobid)
Miscellaneous antidepressants, such as:
Bupropion (Aplenzin, Budeprion XL, Budeprion SR, Buproban, Wellbutrin SR, Wellbutrin XL, Wellbutrin, Zyban)
Mirtazapine (Remeron)
Nefazodone (Serzone)
Trazodone (Desyrel) or trazodone ER (Oleptro)
Vilazodone (Viibryd)
Monoamine oxidase inhibitors (MAOIs), including:
Isocarboxazid (Marplan)
Linezolid (Zyvox)
Methylene blue
Phenelzine (Nardil)
Rasagiline (Azilect)
Selegiline (Eldepryl, Emsam, Zelapar)
Tranylcypromine (Parnate)
Nonsteroidal anti-inflammatory drugs (NSAIDs), such as:
Ibuprofen (Motrin, Advil)
Naproxen (Naprosyn) or naproxen sodium (Aleve, Anaprox, Naprelan)
Diclofenac (Cataflam, Voltaren)
Indomethacin (Indocin)
Nabumetone (Relafen)
Oxaprozin (Daypro)
Celecoxib (Celebrex)
Meloxicam (Mobic)
Etodolac (Lodine)
Ketoprofen (Orudis)
Ketorolac (Toradol)
Phenothiazine medications, including:
Chlorpromazine
Fluphenazine (Prolixin)
Perphenazine
Promethazine (Phenergan)
Thioridazine (Mellaril)
Trifluoperazine
Pimozide (Orap)
Procyclidine (Kemadrin)
Risperidone (Risperdal)
Other SSRI or SNRI medications, such as:
Citalopram (Celexa)
Desvenlafaxine (Pristiq)
Duloxetine (Cymbalta)
Escitalopram (Lexapro)
Fluoxetine (Prozac, Sarafem, Selfemra)
Fluvoxamine (Luvox, Luvox CR)
Milnacipran (Savella)
Paroxetine controlled release (Paxil CR)
Sertraline (Zoloft)
Venlafaxine (Effexor, Effexor XR)
St. John's wort
Tamoxifen (Nolvadex)
Theophylline
Tramadol (Rybix ODT, Ryzolt, Ultram, Ultram ER) or tramadol/acetaminophen (Ultracet)
Tricyclic antidepressants, including:
Amitriptyline (Elavil)
Amoxapine (Asendin)
Clomipramine (Anafranil)
Desipramine (Norpramin)
Doxepin (Sinequan, Silenor)
Imipramine (Tofranil)
Maprotiline (Ludiomil)
Nortriptyline (Pamelor)
Protriptyline (Vivactil)
Trimipramine (Surmontil)
Triptans, including:
Almotriptan (Axert)
Eletriptan (Relpax)
Frovatriptan (Frova)
Naratriptan (Amerge)
Rizatriptan (Maxalt)
Sumatriptan (Alsuma, Imitrex, Sumavel) or sumatriptan/naproxen sodium (Treximet)
Zolmitriptan (Zomig)
Tryptophan
Warfarin (Coumadin, Jantoven).
It is possible that not every paroxetine drug interaction was discussed in this article. Therefore, you should talk with your pharmacist or healthcare provider about the specific drug interactions with paroxetine that may apply to your situation.
You should talk with your healthcare provider prior to taking paroxetine if you have:
Bipolar disorder or a family history of bipolar disorder (also known as manic depression)
A history of suicide attempts or suicidal thoughts
Had a recent heart attack, or if you have unstable heart disease
Diabetes
Seizures or epilepsy
Glaucoma (a condition of the eyes)
Liver disease, including liver failure or cirrhosis
Kidney problems, including kidney failure (renal failure)
Any allergies, including allergies to food, dyes, or preservatives.
Make sure to tell your healthcare provider about all the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements.
Paroxetine may cause harm to an unborn baby. Paroxetine may cause heart defects or serious lung problems in a newborn if you take the medication during pregnancy. Do not use paroxetine if you are pregnant or plan to become pregnant.
Paroxetine has been reported to be excreted into human milk. There are no data on adverse effects in the nursing infant. The manufacturer recommends caution when administering paroxetine to nursing women. Avoid using paroxetine if you are breastfeeding.
Depression, even in its most severe form, is highly treatable. As with many illnesses, getting depression treatment early is more effective and reduces the chance of recurrence.
The most common forms of treatment for depression are medication (antidepressants) and psychotherapy ("talk therapy"). In some cases of severe depression, healthcare providers may recommend electroconvulsive therapy (ECT). Some people may also try complementary or alternative treatments for depression.
For most people, paroxetine is quite effective at treating depression. It is also generally well-tolerated. However, side effects can occur -- or the medicine may not work as well as needed. In such cases, your healthcare provider may recommend an alternative to paroxetine. Some examples of substitute depression medications include:
Other selective serotonin reuptake inhibitors (SSRIs)
Serotonin-norepinephrine reuptake inhibitors (SNRIs)
Norepinephrine and dopamine reuptake inhibitors (NDRIs)
Tricyclic antidepressants
Monoamine oxidase inhibitors (MAOIs).
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. An overdose of paroxetine can be fatal.
People who take too much paroxetine may have overdose symptoms that could include:
Nausea and vomiting
Shakiness (tremor)
Rapid heart rate (tachycardia) or slow heart rate (bradycardia)
Confusion
Dizziness
Seizures
Irregular heart rhythm (arrhythmia)
High blood pressure (hypertension) or low blood pressure (hypotension)
Aggressiveness
Fainting
Muscle pain or muscle stiffness
Liver problems, including hepatitis
Kidney failure
Coma
Loss of life.
If you happen to overdose, seek medical attention immediately.
If you do not take your paroxetine as scheduled, take your missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and continue with your regular schedule. Do not take a double dose.
Paroxetine should be stored at room temperature, away from moisture or heat. It should be kept in an airtight container.
Keep paroxetine and all medications out of the reach of children.
Paroxetine tablets are available in four strengths:
Paroxetine 10 mg tablets
Paroxetine 20 mg tablets
Paroxetine 30 mg tablets
Paroxetine 40 mg tablets.
The liquid form of paroxetine is available in one strength -- Paroxetine oral suspension (liquid) 10 mg per 5 mL (10 mg per teaspoonful).