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 Paxil CR (Paroxetine). If you are concerned about side effects, discuss the risks and benefits of Paxil CR (Paroxetine) with your doctor.

The following side effects have been reported by at least 1% of people taking Paxil CR (Paroxetine). Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• Constipation
• decreased appetite
• decreased sexual desire or ability
• Diarrhea
• dizziness
• drowsiness
• Dry Mouth
• headache
• increased sweating
• menstrual period changes
• nausea
• nervousness
• nightmares
• sun sensitivity
• tremor
• trouble sleeping
• unusual tiredness or weakness
• vomiting
• weight gain
• yawning

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

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

• agitation
• difficulty concentrating
• feelings of paranoia
• hallucinations
• increased cholesterol levels
• Low Blood Pressure (dizziness or fainting when rising from a sitting or lying position)
• muscle pain or weakness
• problems with urination
• restless legs syndrome (irresistible urge to move the legs)
• restlessness
• new or worsening signs of depression (such as feeling sad, losing interest in things you used to enjoy, weight changes, changes in sleep habits, feelings of guilt or worthlessness, thoughts of suicide)
• signs of bleeding (e.g.,bloody nose, blood in urine, coughing blood, bleeding gums, cuts that don't stop bleeding)
• signs of liver problems (e.g., nausea, vomiting, diarrhea, loss of appetite, weight loss, yellowing of the skin or whites of the eyes, dark urine, pale stools)
• skin rash
• swelling of the hands, ankles or feet
• symptoms of Glaucoma (e.g., eye pain, blurred vision)
• symptoms of low blood sodium (confusion, seizures, drowsiness, dryness of mouth, increased thirst, lack of energy)
• talking, feeling, and acting with excitement and activity you cannot control
• uncontrolled body or face movement

Stop taking the medication and seek immediate medical attention if any of the following occur:

• chest pain
• erection without sexual stimulation accompanied by pain or tenderness, lasting for several hours
• seizure or convulsions
• serotonin syndrome (signs include agitation, confusion, diarrhea, Fever, overactive reflexes, poor coordination, restlessness, shivering, sweating, talking or acting with excitement you cannot control, trembling or shaking, twitching)
• signs of bleeding in the stomach (e.g., bloody, black, or tarry stools, spitting up of blood, vomiting blood or material that looks like coffee grounds)
• signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)
• signs of a severe skin reaction such as blistering, peeling, a rash covering a large area of the body, a rash that spreads quickly, or a rash combined with fever or discomfort
• thoughts of suicide or hurting yourself

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 Paxil CR (Paroxetine).

12.5 mg
Each yellow, round and biconvex, enteric, film-coated, controlled-release tablet, with "GSK" engraved on one side and the strength engraved on the other side, contains Paxil CR (Paroxetine) HCl equivalent to 12.5 mg of Paxil CR (Paroxetine). Nonmedicinal ingredients: colloidal silicon dioxide, D&C Yellow No. 10 Aluminum Lake, FD&C Yellow No. 6 Aluminum Lake, glyceryl behenate, hydroxypropyl methylcellulose, lactose monohydrate, magnesium stearate, methacrylic acid copolymer type C, polyethylene glycol, polysorbate 80, polyvinylpyrrolidone, sodium lauryl sulphate, talc, titanium dioxide, triethyl citrate, and yellow ferric oxide.

25 mg
Each pink, round and biconvex, enteric, film-coated, controlled-release tablet, with "GSK" engraved on one side and the strength engraved on the other side, contains Paxil CR (Paroxetine) HCl equivalent to 25 mg of Paxil CR (Paroxetine). Nonmedicinal ingredients: colloidal silicon dioxide, D&C Red No. 30 Aluminum Lake, glyceryl behenate, hydroxypropyl methylcellulose, lactose monohydrate, magnesium stearate, methacrylic acid copolymer type C, polyethylene glycol, polysorbate 80, polyvinylpyrrolidone, red ferric oxide, sodium lauryl sulphate, talc, titanium dioxide, and triethyl citrate.

Do not take Paxil CR (Paroxetine) CR if you:

• are allergic to Paxil CR (Paroxetine) or any ingredients of the medication
• are taking an MAO inhibitor (e.g., Phenelzine, Tranylcypromine, Moclobemide) or have taken a MAO inhibitor within the past 2 weeks; do not start treatment with an MAO inhibitor until at least 2 weeks after stopping treatment with Paxil CR (Paroxetine) controlled release
• take the medication Pimozide
• take the medication thioridazine

There may be an interaction between Paxil CR (Paroxetine) controlled release and any of the following:

• Abiraterone
• acetylsalicylic acid (ASA)
• alcohol
• Alfuzosin
• alteplase
• Amiodarone
• amphetamines (e.g., Dextroamphetamine, lisdexamphetamine, methamphetamine)
• antihistamines (e.g., Diphenhydramine, Hydroxyzine)
• antipsychotic medications (e.g., Chlorpromazine, Haloperidol, Olanzapine, Quetiapine, Risperidone)
• Apixaban
• Atomoxetine
• barbiturates (e.g., butalbital, pentobarbital, Phenobarbital)
• benzodiazepines (e.g., Alprazolam, Diazepam, Lorazepam)
• beta blockers (e.g., Carvedilol, Propranolol, Metoprolol)
• Bromocriptine
• Bupropion
• Buspirone
• Cabergoline
• Captopril
• certain antiarrhythmic medications (e.g., Disopyramide, Flecainide, Propafenone)
• chloroquine
• chloral hydrate
• chloroquine
• Cimetidine
• Cinacalcet
• clopidogrel
• Cyclophosphamide
• dabigatran
• Darifenacin
• Dasatinib
• Diabetes medications (e.g., chlorpropamide, glipizide, Glyburide, insulin, Metformin, Nateglinide, Rosiglitazone)
• Desmopressin
• Dextromethorphan
• dipyridamole
• dofetilide
• Domperidone
• Doxorubicin
• Dronedarone
• efavirenz
• ergot alkaloids (e.g., ergotamine, Dihydroergotamine)
• Galantamine
• general anesthetics (medications used to put people to sleep before surgery)
• glucosamine
• Heparin
• herbal products that affect blood clotting (e.g., cat's claw, chamomile, fenugreek, evening primrose, feverfew, garlic, ginger, ginseng, turmeric)
• Ifosfamide
• Irinotecan
• ketoconazole
• Levothyroxine
• Linezolid
• lithium
• Losartan
• low-molecular-weight heparins (e.g., Dalteparin, Enoxaparin, Tinzaparin)
• macrolide antibiotics (e.g., clarithromycin, erythromycin)
• MAO inhibitors (e.g., linezolid, moclobemide, phenelzine, Selegiline, tranylcypromine)
• Methadone
• methylene blue
• Metoclopramide
• metyrosine
• mexilitine
• mifepristone
• Mirabegron
• Mirtazapine
• multivitamins/minerals
• muscle relaxants (e.g., Baclofen, Cyclobenzaprine, methocarbamol, orphenadrine, Tizanidine)
• narcotic pain relievers (e.g., Codeine, Fentanyl, methadone, Morphine, Oxycodone)
• nefazodone
• Nilotinib
• non-steroidal anti-inflammatory medications (NSAIDs; e.g., Diclofenac, ibuprofen, Indomethacin, naproxen)
• omega-3 fatty acids
• peginterferon alfa-2b
• Pentoxifylline
• Pravastatin
• quinidine
• quinine
• quinolone antibiotics (e.g., levofloxacin, moxifloxacin)
• Rasagiline
• ritonavir
• Rivaroxaban
• scopolamine
• seizure medications (e.g., Carbamazepine, Clobazam,  felbamate, Levetiracetam, phenobarbital, Phenytoin, primidone, Topiramate, Valproic acid, zonisamide)
• serotonin/norepinephrine reuptake inhibitors (SNRIs e.g., Desvenlafaxine, Duloxetine, Venlafaxine)
• other selective serotonin reuptake inhibitors (SSRIs; e.g., Citalopram, Fluoxetine, Sertraline)
• 5-HT3 antagonists (e.g., Granisetron, Ondansetron)
• St. John's wort
• Tamoxifen
• Tapentadol
• terbinafine
• Tetrabenazine
• thiazide diuretics (e.g., Hydrochlorothiazide, Indapamide)
• Ticagrelor
• Ticlopidine
• Tolterodine
• Tramadol
• Trazodone
• tricyclic antidepressants (e.g., Amitriptyline, Imipramine, Nortriptyline)
• "triptan" migraine medications (e.g., Sumatriptan, Rizatriptan, Zolmitriptan)
• tyrosine kinase inhbitors (e.g., imatinib, Lapatinib, Pazopanib, Sunitinib)
• Tryptophan
• vitamin E
• warfarin
• Zolpidem
• Zopiclone

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. 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 Paxil CR (Paroxetine). Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications 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.

Before you begin taking a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should take Paxil CR (Paroxetine).

Abnormal bleeding: Paxil CR (Paroxetine) CR, like other similar medications, may cause abnormal bleeding, including bleeding in the stomach or intestines. If you have, or have had, a history of bleeding disorders, you should discuss with your doctor how Paxil CR (Paroxetine) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Paxil CR (Paroxetine), and whether any special monitoring is needed.

Report any unusual bruising or bleeding to your doctor, especially if you are taking medications that affect blood clotting. These medications include acetylsalicylic acid (Asa), Clopidogrel, Dipyridamole, nonsteroidal anti-inflammatory drugs (NSAIDs; e.g., Ibuprofen or Naproxen), other anticoagulant medications (e.g., Warfarin), and certain antipsychotic medications.

Bone fracture: Paxil CR (Paroxetine) may increase the risk of bone fractures (breaks) when taking Paxil CR (Paroxetine). If you have Osteoporosis or any other illness that increases your risk for breaking bones, or are at risk for developing osteoporosis, discuss with your doctor how Paxil CR (Paroxetine) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Paxil CR (Paroxetine), and whether any special monitoring is needed.

Drowsiness/reduced alertness: Although Paxil CR (Paroxetine) CR is not known to cause drowsiness, it is advisable to avoid driving or operating hazardous machinery until you determine how Paxil CR (Paroxetine) affects your ability to do these things safely.

Glaucoma: Paxil CR (Paroxetine) CR can cause an increase in the pressure in the eye, making symptoms of glaucoma worse. If you have narrow-angle glaucoma, discuss with your doctor how Paxil CR (Paroxetine) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Paxil CR (Paroxetine), and whether any special monitoring is needed. Any changes in vision should be reported to the doctor as soon as possible.

Heart disease: If you have heart disease, discuss with your doctor how Paxil CR (Paroxetine) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Paxil CR (Paroxetine), and whether any special monitoring is needed.

Kidney function: People with Kidney Disease may need lower doses of Paxil CR (Paroxetine). If you have kidney disease or reduced kidney function, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Paxil CR (Paroxetine), and whether any special monitoring is needed.

Liver function: Liver disease or reduced liver function may cause Paxil CR (Paroxetine) to build up in the body, causing side effects. If you have liver problems, discuss with your doctor how Paxil CR (Paroxetine) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Paxil CR (Paroxetine), and whether any special monitoring is needed. Your doctor may want to test your liver function regularly with blood tests while you are taking Paxil CR (Paroxetine).

If you experience symptoms of liver problems such as fatigue, feeling unwell, loss of appetite, nausea, yellowing of the skin or whites of the eyes, dark urine, pale stools, abdominal pain or swelling, and itchy skin, contact your doctor immediately.

Mania: Paxil CR (Paroxetine) CR may cause symptoms of mania to worsen or to return. If you have a history of manic symptoms or bipolar disorder, discuss with your doctor how Paxil CR (Paroxetine) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Paxil CR (Paroxetine), and whether any special monitoring is needed.

Seizures: Paxil CR (Paroxetine) CR may cause an increase in seizures for people with a seizure disorder or a history of seizures. If you have a history of seizures, discuss with your doctor how Paxil CR (Paroxetine) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Paxil CR (Paroxetine), and whether any special monitoring is needed. Anyone who develops seizures should seek immediate medical attention.

Serotonin Syndrome: Severe reactions are possible when Paxil CR (Paroxetine) CR is combined with other medications that act on serotonin, such as tricyclic antidepressants, "triptan" medications for migraine and some medications to treat nausea due to chemotherapy. These combinations should be avoided. Symptoms of a reaction may include muscle rigidity and spasms, difficulty moving, changes in mental state including delirium and agitation. Coma and death are possible.

If you are taking other medications that affect serotonin, discuss with your doctor how Paxil CR (Paroxetine) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Paxil CR (Paroxetine), and whether any special monitoring is needed.

Stopping the medication: Stopping Paxil CR (Paroxetine) 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. Your doctor may want you to decrease the dose of the medication gradually when it is time to stop taking Paxil CR (Paroxetine).

Suicidal or agitated behaviour: People taking Paxil CR (Paroxetine) may feel agitated (restless, anxious, aggressive, emotional, and feeling not like themselves), or they may want to hurt themselves or others. These behavioural changes may be more likely to occur in children and adolescents, however they are possible for all age groups that use Paxil CR (Paroxetine). These symptoms may occur within several weeks after starting Paxil CR (Paroxetine). If you experience these side effects or notice them in a family member who is taking Paxil CR (Paroxetine), contact your doctor immediately. Your doctor will monitor you closely for these side effects while you are taking Paxil CR (Paroxetine).

Pregnancy: Paxil CR (Paroxetine) should not be used during pregnancy unless the benefits outweigh the risks. Paxil CR (Paroxetine) has been reported to cause an increase in birth defects, primarily of the heart, in babies born to women who have taken it in the first trimester. It has also been reported that babies born to women who have taken Paxil CR (Paroxetine) 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)that result in an increase in the length of hospital stay. If you become pregnant while taking Paxil CR (Paroxetine), contact your doctor immediately.

Breast-feeding: Paxil CR (Paroxetine) passes into breast milk. If you are a breast-feeding mother and are taking Paxil CR (Paroxetine), it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children and adolescents: The safety and effectiveness of Paxil CR (Paroxetine) for those less than 18 years of age have not been established. The use of Paxil CR (Paroxetine) by children and adolescents less than 18 years old may cause behavioural and emotional changes, such as suicidal thoughts and behaviour.

Seniors: Seniors may need lower doses of Paxil CR (Paroxetine), and they should be closely monitored by their doctor when taking Paxil CR (Paroxetine).