Paroxetine belongs to the class of medications called selective serotonin reuptake inhibitors (SSRIs). It is used for the treatment of depression, obsessive-compulsive disorder, panic disorder, post-traumatic stress disorder, generalized anxiety disorder, and social phobia. It works by affecting the balance of chemicals in the brain that are associated with depression and anxiety disorders. It may take several weeks before the full beneficial effects of this medication are seen.

Your doctor may have suggested this medication for conditions other than the ones listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

The recommended adult dose of paroxetine ranges from 20 mg to 60 mg once daily in the morning, with or without food. The dose depends on the individual and on the condition being treated. Swallow the tablet whole; do not chew it.

Do not stop taking this medication without consulting your doctor, as some people experience physical symptoms when stopping the medication suddenly. Your doctor may want you to decrease the dose of the medication gradually when it is time to stop taking paroxetine.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones given here, do not change the way that you are taking the medication without consulting your doctor.

It is important that this medication be taken on a regular schedule exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue on with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue on with your regular dosing schedule. Do not take a double dose to make up for a missed one.

Paxil® is available in strengths of 10 mg, 20 mg, and 30 mg.

10 mg: Each yellow, bisected, film-coated, oval tablet, with "PAXIL" engraved on one side and "10" engraved on the other side, contains paroxetine 10 mg.

20 mg: Each pink, bisected, film-coated, oval tablet, with "PAXIL" engraved on one side and "20" engraved on the other side, contains paroxetine 20 mg.

30 mg: Each blue, film-coated, oval tablet, with "PAXIL" engraved on one side and "30" engraved on the other side, contains paroxetine 30 mg.

Nonmedicinal ingredients: dibasic calcium phosphate dihydrate, hydroxypropyl methylcellulose, hypromellose, magnesium stearate, polyethylene glycols, polysorbate 80, sodium starch glycolate, and titanium dioxide. One or more of the following dyes are in these medications: D&C Red No. 30 Aluminum Lake (20 mg tablet), D&C Yellow No. 10 and No. 6 Aluminum Lake (10 mg tablet), and FD&C Blue No. 2 Aluminum Lake (30 mg tablet).

Paroxetine should not be used by anyone who:

• has a known or suspected allergy to the medication or its ingredients
• takes MAO inhibitor medications or has taken a MAO inhibitor within the two weeks
• takes thioridazine
• takes pimozide

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent. The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your health professional.

The following side effects may go away as your body becomes used to the medicine; check with your doctor if they continue or become bothersome.

More common
• constipation
• decreased sexual ability
• diarrhea
• dizziness
• drowsiness
• dryness of mouth
• headache
• increased sweating
• nausea
• trouble sleeping
• unusual tiredness or weakness

Less common
• anxiety or nervousness
• blurred vision or other vision changes
• back pain
• change in sense of taste
• decreased or increased appetite
• decreased sexual desire
• flatulence
• flu-like symptoms
• problems with urination
• stomach discomfort or pain
• tingling, burning, or prickling sensations
• trembling or shaking
• vomiting
• yawning
• weight loss or gain

Check with your doctor as soon as possible if any of the following side effects occur:

Less common
• agitation
• chest pain
• fast or irregular heartbeat
• muscle pain or weakness
• skin rash

Rare
• absence of or decrease in body movements
• difficulty speaking
• erection without sexual stimulation accompanied by pain or tenderness
• inability to move eyes
• incomplete, sudden, or unusual body or facial movements
• low blood sodium (confusion, seizures, drowsiness, dryness of mouth, increased thirst, lack of energy)
• red or purple patches on skin
• serotonin syndrome - a condition characterized by the following symptoms:
  • confusion
  • diarrhea
  • fever
  • poor coordination
  • restlessness
  • shivering
  • sweating
  • trembling or shaking
  • twitching
• talking, feeling, and acting with excitement and activity you cannot control
• feelings of paranoia
• seizures

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Be sure to inform your physician of all your medical conditions before you begin taking a medication. Some conditions can affect how you should take this medication.

Abnormal bleeding: Bleeding from the skin and nose has been reported only rarely. People who are taking medications that increase the risk of bleeding (such as warfarin or NSAIDs) or people who have had bleeding disorders should be cautious while taking this medicine.

Depression: People taking this medication for depression should be closely monitored by their doctor.

Drowsiness/reduced alertness: Although paroxetine is not known to cause drowsiness, people taking the medication are advised to avoid driving or operating hazardous machinery until they determine that paroxetine does not affect them adversely.

Glaucoma: People with narrow-angle glaucoma should be closely monitored by their doctor while taking this medication.

Heart disease: People with heart disease who take this medication may need to be closely monitored by their doctor.

Liver or kidney disease: People with liver or kidney disease may need lower doses of this medication and should be closely monitored by their doctor.

Mania: Paroxetine may activate mania and therefore should be used cautiously by those with a history of mania.

Suicidal or agitated behaviour: People taking this medication may feel agitated (restless, anxious, aggressive, emotional, and feeling not like themselves), or they may want to hurt themselves or others. These symptoms may occur within several weeks after starting this medication. People should be closely monitored by their doctor for emotional and behaviour changes.

Stopping the medication: Stopping this medication suddenly may lead to side effects such as dizziness, abnormal dreams, numbness or tingling sensations, agitation, anxiety, nausea, vomiting, sweating, or other symptoms. If you are thinking of stopping the medication, check with your doctor first.

Seizures: People with a history of seizures should be closely monitored by their doctor while taking this medication. Anyone who develops seizures should stop taking paroxetine.

Pregnancy: The safety of paroxetine for use by pregnant women has not been established. It has been reported that babies born to pregnant women who have taken medications of this kind during the last trimester of pregnancy may experience adverse effects (such as breathing problems, seizures, trouble feeding, vomiting, low blood sugar, shaking, jitteriness, irritability, and constant crying). Physicians and pregnant women should carefully consider the benefits and the risks of all treatment options.

Breast-feeding: Paroxetine passes into breast milk. Women should not nurse their infants while taking paroxetine unless, in the opinion of the doctor, breast-feeding is necessary.

Children: The safety and effectiveness of paroxetine for children under 18 years of age have not been established. The use of this medication in children below the age of 18 may cause behavioural and emotional changes, such as suicidal thoughts and behaviour.

Seniors: Seniors may need lower doses of paroxetine and should be closely monitored by their doctor while taking this medication.

The following substances may affect how paroxetine works or increase the risk of side effects:

• alcohol
• anticonvulsants (e.g., phenytoin)
• certain antiarrhythmic drugs (e.g., propafenone, flecainide)
• certain tricyclic antidepressants (e.g., nortriptyline, amitriptyline, imipramine, desipramine)
• cimetidine
• lithium
• MAO inhibitors (e.g., phenelzine, tranylcypromine)
• metoprolol
• neuroleptics (e.g., haloperidol, oxazepam)
• phenobarbital
• phenothiazines (e.g., perphenazine, chlorpromazine)
• other SSRIs (e.g., fluoxetine, sertraline)
• St. John's wort
• thioridazine
• tryptophan

Paroxetine may affect how the following medications work or increase the risk of side effects:

• beta-blockers (e.g., metoprolol, propranolol)
• pimozide
• procyclidine
• St. John's wort
• sibutramine
• sumatriptan
• theophylline
• warfarin

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. In many cases, interactions are intended or are managed by close monitoring. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications that you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.