Venlafaxine ER

Medically Reviewed by Dr. Harshi Dhingra, M.D.

Last Reviewed: Mar 10, 2023

Warnings

Venlafaxine ER (EFFEXOR XR) Risks, Warnings, and Complications

Venlafaxine ER can cause serious health complications in some people. Talk to your doctor or pharmacist about other treatment options if you are at increased risk of complications from venlafaxine ER use.

SUICIDE RISK: Taking antidepressant medications, including venlafaxine ER, can lead to new or worsening symptoms of depression and suicidal thoughts and behaviors. The risk is particularly high in young adults under 24 years of age, but anyone can develop suicidal ideation, especially in the first few months of treatment and after dose adjustments. Tell your healthcare provider if you notice any unusual mood changes or behaviors (for example, anxiety, trouble sleeping, sadness, irritation, agitation, restlessness). People in your household should know how to get medical help in case you are unable to do so yourself.
SEROTONIN SYNDROME: People who take venlafaxine ER can develop a rare, but serious condition called serotonin syndrome which happens because of too much serotonin in the brain. The risk of this happening is higher when you are also taking other medications that can increase serotonin levels in the brain, such as certain other antidepressants, psychiatric medications used to treat other serious mental illnesses, migraine medications, and pain medications. Give your doctor and pharmacist a full list of your medications before starting venlafaxine ER. Stop taking Effexor XR and seek immediate medical attention if you develop symptoms of serotonin syndrome such as sweating, fast heart rate, severe muscle stiffness, muscle spasms, fever, and confusion.
EFFECTS ON BLOOD PRESSURE: Patients taking venlafaxine can experience low blood pressure, falls, and fainting. This typically happens in the first few days of taking the medicine, but can happen any time during treatment, especially after a dose increase. The risk is higher in elderly patients, those with a history of gait disturbances, people on high doses of venlafaxine, and those taking other drugs that also lower blood pressure. Get up slowly from sitting or lying positions. Tell your healthcare provider if you experience dizziness that does not get better after a few days. Venlafaxine can also lead to high blood pressure, so your healthcare provider may ask you to monitor your blood pressure more frequently.
BLEEDING RISK: Venlafaxine can increase the risk of bruising and bleeding, especially if you're also taking nonsteroidal anti-inflammatory drugs (NSAIDs) like aspirin and ibuprofen. These bleeding events can be life-threatening. Tell your healthcare provider if you develop any unusual bruising such as from the gums or nose, purple spots on the skin, pink or red urine, or black or tarry stools. Also, tell your healthcare provider if you take blood thinners, because you may have to change the dose.
GLAUCOMA: Patients taking venlafaxine ER can develop angle-closure glaucoma, an eye condition in which there is an increase in pressure inside the eye. Your doctor might send you for regular eye checkups during treatment with venlafaxine ER. Call your doctor without delay if you develop any eye pain, blurred vision, or vision changes while on this medicine.
MANIA OR HYPOMANIA: Depression can be the first symptom of a mental illness called bipolar disorder, in which there are alternating episodes of mania (abnormal excitement, delusions, overactivity, and euphoria) and depression (low mood). Treating someone who has bipolar disorder with an antidepressant such as venlafaxine alone can lead to an activation of a manic episode. The risk of bipolar disorder is higher if someone in your family has it. Your healthcare provider will make sure you don't have bipolar disorder before starting you on venlafaxine. Tell your healthcare provider right away if you notice any unusual changes in mood or behavior while on this medicine.
WITHDRAWAL SYMPTOMS: Suddenly stopping Effexor XR (venlafaxine ER) can lead to withdrawal symptoms like dizziness, nausea, vomiting, irritability, agitation, headache, nightmares, and prickling or tingling sensations in the skin. Your doctor will tell you how to lower your dose of venlafaxine extended release tablets/capsules gradually to avoid withdrawal effects.

Precautions Before Starting Venlafaxine ER (EFFEXOR XR)

Tell your doctor if you are allergic to venlafaxine ER, any of the active or inactive ingredients in venlafaxine ER, other antidepressant drugs, or any other medications. Your pharmacy can give you a list of ingredients.

Give your doctor and pharmacist a complete list of your medications, including prescription drugs, over-the-counter medicines, vitamins, supplements, and herbal products, especially St. John’s Wort and tryptophan. This can help avoid possible drug interactions.

Give your doctor a complete medical history. Venlafaxine ER may not be right for people with certain medical conditions such as recent heart attack, heart disease, high blood pressure, high cholesterol, seizures, glaucoma, kidney disease, liver disease, or thyroid disease.

Tell your doctor if you are pregnant, could be pregnant, plan to get pregnant, or are breastfeeding. Venlafaxine ER can cause problems in the newborn baby after delivery if the medicine is taken during pregnancy, especially during the last few months of pregnancy.

Precautions During Use of Venlafaxine ER (EFFEXOR XR)

Keep all your medical appointments while on venlafaxine ER. Your doctor may adjust your dose, order certain laboratory tests, or prescribe regular eye checkups during treatment with this medicine.

Venlafaxine ER can make you drowsy and dizzy. Do not drive a car or operate machinery until you know how it affects you. Avoid drinking alcohol while on this medicine because alcohol can make these side effects worse.

Tell your doctor if you become pregnant while on venlafaxine ER.

Tell all your healthcare providers you are on venlafaxine ER before any surgery, including dental procedures.

Venlafaxine ER (EFFEXOR XR) Drug Interactions

Certain other drugs can affect how venlafaxine ER works. Possible interactions between venlafaxine ER and other medicines can increase the risk of severe adverse effects.

Taking Venlafaxine ER is not recommended if you are taking or have taken a monoamine oxidase inhibitor (MAO inhibitor) within the past 14 days. Examples of MAO inhibitors are linezolid (Zyvox), tranylcypromine (Parnate), isocarboxazid (Marplan), phenelzine (Nardil), selegiline (Eldepryl, Zelapar, Emsam), and methylene blue.

The following medications can have possible interactions with venlafaxine ER:

Stimulant medications such as amphetamine (in Adderall, in Mydayis), methamphetamine (Desoxyn), and dextroamphetamine (Dexedrine, in Adderall)
Blood thinners (anticoagulants) such as warfarin (Coumadin, Jantoven)
Nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin, ibuprofen (Motrin, Advil) and naproxen (Naprosyn, Aleve)
Anti-anxiety medications such as buspirone
H2 blockers like cimetidine (Tagamet)
Atypical antipsychotics such as clozapine (Clozaril)
Conventional antipsychotics such as haloperidol (Haldol)
Antimanic agents like lithium (Lithobid)
Water pills (diuretics)
Opioid pain medications such as fentanyl (Duragesic, Actiq, Fentora, Subsys) and tramadol (Ultram, Conzip, Qdolo, in Ultracet)
HIV medications such as indinavir (Crixivan)
Antifungal drugs like ketoconazole
Weight loss medications like phentermine (Adipex P, , Qsymia, Lomaira)
Triptan medications prescribed for migraine such as sumatriptan (Imitrex), naratriptan (Amerge), eletriptan (Relpax), almotriptan, frovatriptan (Frova), zolmitriptan (Zomig), and rizatriptan (Maxalt)
Beta blockers like metoprolol (Lopressor, Toprol, Kapspargo Sprinkle)
Antidepressants like mirtazapine (Remeron)
Tricyclic antidepressants such as amoxapine, amitriptyline, clomipramine (Anafranil), doxepin (Silenor), desipramine (Norpramin), imipramine (Tofranil), protriptyline, nortriptyline (Pamelor), and trimipramine
Selective serotonin reuptake inhibitors (SSRIs) such as escitalopram (Lexapro), citalopram (Celexa), sertraline (Zoloft), fluvoxamine (Luvox), fluoxetine (Prozac, in Symbyax), paroxetine (Paxil)
Other SNRIs such as desvenlafaxine (Pristiq) and duloxetine (Cymbalta)
Sedatives, sleeping pills, tranquilizers

The above list may not describe all the medications that can have drug interactions with venlafaxine ER. Give your doctor or pharmacist a complete list of your medications, including prescription drugs, OTC medications, dietary supplements, and herbal remedies. Also, tell your healthcare professional if you smoke, drink alcohol, or use recreational drugs because some of these substances can cause serious health complications when used with prescription medications.

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