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 Desvenlafaxine. If you are concerned about side effects, discuss the risks and benefits of Desvenlafaxine with your doctor.

The following side effects have been reported by at least 1% of people taking Desvenlafaxine. 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.

• abnormal dreams
• anxiety
• chills
• Constipation
• decreased appetite
• Diarrhea
• difficulty concentrating
• difficulty urinating
• dilated pupils
• dizziness
• drowsiness
• Dry Mouth
• feeling jittery
• hair loss
• headache
• hot flushes
• increased sweating
• irritability
• muscle stiffness
• nausea
• nervousness
• rash
• ringing in the ears
• sexual problems (such as decreased sex drive, difficulty getting an erection, or difficulty having an orgasm)
• spinning sensation
• taste changes
• tingling, burning, or prickly sensations
• trembling or shaking
• trouble sleeping
• tiredness
• vision changes
• vomiting
• weakness
• weight changes
• yawning

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

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

• cold hands and feet
• dizziness when rising from standing or lying position
• fainting
• increased blood pressure
• increased cholesterol or triglyceride levels
• new or worsened emotional or behavioural problems
• pounding or fast heartbeat
• signs of bleeding (e.g., bloody nose, blood in urine, unusual bruising, bleeding gums, cuts that don't stop bleeding)
• symptoms of increased pressure in the eyes (e.g., decreased or blurred vision, eye pain, red eye, swelling of the eye)
• symptoms of low sodium levels in the blood (e.g., achy, stiff, or uncoordinated muscles; confusion, tiredness, weakness)
• symptoms of mania (e.g., decreased need for sleep, elevated or irritable mood, racing thoughts)
• uncontrollable movements of the body or face

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

• seizure
• signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)
• symptoms of severely increased blood pressure: (e.g., chest pain, blurred vision, dizziness, excessive tiredness, headache, stronger or faster heartbeat)
• symptoms of serotonin syndrome
• confusion
• fast heartbeat
• hallucinations
• restlessness
• shaking
• shivering
• sudden jerking of muscles
• sweating

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 Desvenlafaxine.

50 mg
Each light pink, rounded-square-shaped, biconvex, film-coated tablet, engraved with "APO" on one side and "DV" over "50" on the other side, contains 50 mg of desvenlafaxine (as base). Nonmedicinal ingredients: anhydrous citric acid, colloidal silicon dioxide, euroxide red iron oxide, hypromellose, magnesium stearate, microcrystalline cellulose, polyethylene glycol, polyvinyl alcohol, talc, titanium dioxide, and yellow iron oxide.

100 mg
Each reddish-orange, rounded-square-shaped, biconvex, film-coated tablet, engraved with "APO" on one side and "DV" over "100" on the other side, contains 100 mg of desvenlafaxine (as base). Nonmedicinal ingredients: anhydrous citric acid, colloidal silicon dioxide, euroxide red iron oxide, hypromellose, magnesium stearate, microcrystalline cellulose, polyethylene glycol, polyvinyl alcohol, talc, titanium dioxide, and red iron oxide.

Do not take desvenlafaxine if you:

• are allergic to desvenlafaxine, Venlafaxine, or any ingredients of the medication
• are currently taking an MAO inhibitor (e.g., Phenelzine, Tranylcypromine, methylene blue, Linezolid) or have taken one in the last 14 days (MAO inhibitors should not be taken until at least 1 week after stopping treatment with desvenlafaxine)

There may be an interaction between desvenlafaxine and any of the following:

• acetylsalicylic acid (ASA)
• alcohol
• alpha-agonists (e.g., Clonidine, methyldopa)
• amphetamines (e.g., Dextroamphetamine, Lisdexamfetamine)
• antipsychotics (e.g., Haloperidol, Quetiapine, Olanzapine, Risperidone)
• Apixaban
• Buspirone
• Clopidogrel
• Cyclobenzaprine
• dabigatran
• Dasatinib
• dexmethylphenidate
• Dextromethorphan
• Dipyridamole
• Edoxaban
• Epinephrine
• ergot alkaloids (e.g., ergotamine, Dihydroergotamine)
• glucosamine
• Heparin
• linezolid
• lithium
• low molecular weight heparins (e.g., Dalteparin, Enoxaparin, Tinzaparin)
• Methadone
• methylene blue
• Methylphenidate
• Mirtazapine
• monoamine oxidase inhibitors (M.O.S. e.g., Moclobemide, phenelzine, Rasagiline, Selegiline, tranylcypromine)
• multiple vitamin/mineral supplements
• narcotic pain medications (e.g., Codeine, Fentanyl, Morphine)
• nonsteroidal anti-inflammatory drugs (NSAIDs; e.g., ibuprofen, Indomethacin, Ketorolac, naproxen)
• Obinutuzumab
• omega-3 fatty acids
• Pentoxifylline
• Pseudoephedrine
• Rivaroxaban
• St. John's wort
• selective serotonin reuptake inhibitors (SSRIs; e.g., Citalopram, Fluoxetine, Paroxetine, Sertraline)
• serotonin antagonists (e.g., Granisetron, Ondansetron)
• other serotonin/norepinephrine reuptake inhibitors (SNRIs; e.g., Duloxetine, venlafaxine)
• Tapentadol
• Ticagrelor
• Ticlopidine
• tipranavir
• tramadol
• Trazodone
• tricyclic antidepressants (e.g., Amitriptyline, Desipramine, Imipramine)
• triptan medications (e.g., Naratriptan, rizatriptan, sumatriptan)
• Tryptophan supplements
• vitamin E
• 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. 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 Desvenlafaxine. 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 using 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 use Desvenlafaxine.

Abnormal bleeding: There have been some reports of abnormal bleeding associated with desvenlafaxine. The risk of bleeding may be increased by other medications that affect bleeding (e.g., Ibuprofen, Naproxen, acetylsalicylic acid [Asa], Warfarin). If you notice unusual bleeding or bruising, contact your doctor right away. If you have a bleeding disorder, discuss with your doctor how Desvenlafaxine may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Blood pressure: Treatment with desvenlafaxine may increase blood pressure. People with high blood pressure should have their blood pressure controlled before taking Desvenlafaxine. Your doctor will check your blood pressure regularly while you are taking Desvenlafaxine.

Bone fractures: Medications in the same class as desvenlafaxine have been reported to increase the risk for bone fractures. If you have Osteoporosis or are at risk for developing osteoporosis, or have had a recent bone fracture, discuss with your doctor how Desvenlafaxine may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Desvenlafaxine, and whether any special monitoring is needed.

Cholesterol: Desvenlafaxine may increase cholesterol and triglyceride levels. Your doctor may monitor these levels while you are taking Desvenlafaxine. If you have High Cholesterol or triglyceride levels, discuss with your doctor how Desvenlafaxine may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Drowsiness/reduced alertness: If you are taking desvenlafaxine, do not drive a car or perform hazardous tasks until you have determined that Desvenlafaxine does not impair your ability to perform these tasks safely.

Glaucoma: Desvenlafaxine may cause the symptoms of glaucoma (increased pressure in the eye) to become worse. If you have glaucoma, discuss with your doctor how Desvenlafaxine may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed. Report any changes in vision to your doctor as soon as possible while you are taking Desvenlafaxine.

Heart and other blood vessel disease: If you have heart disease or blood vessel disease in the brain (e.g., history of a Stroke), discuss with your doctor how Desvenlafaxine may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Kidney function: Reduced kidney function or Kidney Disease may cause Desvenlafaxine to build up in the body, causing side effects. If you have reduced kidney function, discuss with your doctor how Desvenlafaxine may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Desvenlafaxine, and whether any special monitoring is needed.

Low sodium levels: Desvenlafaxine may cause low sodium levels, especially for seniors, people who are dehydrated, and people taking diuretics (water pills). Contact your doctor if you notice symptoms of low sodium such as confusion, concentration or memory problems, weakness, or unsteadiness.

Lung problems: Rarely, some people taking Desvenlafaxine may develop certain lung problems or infections. These can become serious very quickly. If you notice any coughing, difficulty breathing, or chest discomfort while taking desvenlafaxine, see your doctor as soon as possible.

Mania or bipolar disorder: Desvenlafaxine may activate mania. If you have a history of mania or bipolar disorder, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Desvenlafaxine, and whether any special monitoring is needed.

Narrowing or blockage of the gastrointestinal tract: This medication should not be taken by people who have narrowing or blockage of the gastrointestinal tract (esophagus, stomach, intestines) due to medical conditions such as "short gut" syndrome, Cystic Fibrosis, or inflammatory bowel disease (e.g., Ulcerative Colitis).

Seizures: As with other antidepressants, Desvenlafaxine may increase the risk of seizures. If you have had seizures in the past, discuss with your doctor how Desvenlafaxine may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Serotonin syndrome or neuroleptic malignant syndrome: This medication may cause the rare but potentially life-threatening conditions called serotonin syndrome or neuroleptic malignant syndrome, especially when used with other medications that increase serotonin levels (e.g., Sumatriptan, Rizatriptan, Tramadol, St. John's wort). Get immediate medical attention if you experience symptoms such as:

• agitation
• confusion
• diarrhea
• fast heart rate
• Fever
• hallucinations
• increased body temperature
• lack of coordination
• nausea
• overactive reflexes
• vomiting

Stopping the medication: Stopping Desvenlafaxine suddenly may lead to unwanted symptoms such as:

• agitation
• anxiety
• confusion
• diarrhea
• dizziness
• electric shock sensations
• fatigue
• headache
• irritability
• nausea
• sleep disturbances
• sweating

Although these symptoms usually go away without treatment, tell your doctor if you experience any of these symptoms. When Desvenlafaxine is stopped, it should be stopped gradually as directed by your doctor.

Suicidal or agitated behaviour: People taking antidepressants such as desvenlafaxine may feel agitated (restless, anxious, aggressive, emotional, trouble sleeping, and feeling not like themselves), or they may want to hurt themselves or others. These symptoms may occur within the first few weeks of starting Desvenlafaxine. If you notice any changes in mood, behaviours, thoughts, or feelings in yourself or someone who is taking Desvenlafaxine, contact a doctor immediately. Your doctor will monitor you closely for behaviour changes, especially at start of treatment or when your dose is increased or decreased.

Pregnancy: Newborns whose mothers take medications such as desvenlafaxine during the third trimester of pregnancy may experience complications that require prolonged hospitalization. These complications normally resolve over time.

Desvenlafaxine should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking Desvenlafaxine, contact your doctor immediately. Do not stop taking Desvenlafaxine without talking to your doctor. If Desvenlafaxine is stopped, it should be stopped gradually as directed by your doctor.

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

Children: The safety and efficacy of using this medication have not been established for children less than 18 years of age. The use of Desvenlafaxine by children less than 18 years old may cause behavioural and emotional changes, such as suicidal thoughts and behaviour.

Seniors: Seniors may be more likely to experience side effects, especially increased blood pressure, with Desvenlafaxine than younger adults. Lower doses may be needed.

Desvenlafaxine belongs to the class of antidepressant medications known as selective serotonin and norepinephrine reuptake inhibitors (SNRIs). It is used to treat Depression.

It works on the central nervous system (CNS) to elevate mood by increasing the amount of 2 neurotransmitters (chemical messengers) called serotonin and norepinephrine that are available in certain parts of the brain. It may take several weeks before the full benefits of Desvenlafaxine are seen.

Desvenlafaxine may be available under multiple brand names and/or in several different forms. Any specific brand name of Desvenlafaxine may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of Desvenlafaxine may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those 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 Desvenlafaxine without consulting your doctor.

Do not give Desvenlafaxine 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.