Venlafaxine Interactions With Other Drugs And Substances

Last Updated: February 19, 2020

Authored by Nena Messina, Ph.D.

A healthcare provider may prescribe Effexor with other medications if there is a medical need. It is important to notify a healthcare professional if any other medications are taken. A doctor may adjust the dose to avoid possible side effects of interaction with venlafaxine in such a case. However, some abusers may mix Venlafaxine HCL with other drugs for recreational purposes. As a result, very dangerous effects can occur after such interactions with Effexor. Many severe interactions with Effexor can also occur subsequently self-medication. It is necessary to consult a doctor before mixing Effexor with other drugs to avoid the risks of severe venlafaxine interactions.

Interactions With Antidepressants

Many patients with depression may respond poorly to venlafaxine monotherapy. A doctor can combine venlafaxine with another antidepressant for treating refractory depression. Despite the risks of increased adverse reactions or drug-drug interaction with antidepressants, these combinations are common in medical practice. Headache, nausea, constipation, and drowsiness are common side effects of venlafaxine drug interactions with other antidepressants. It is recommended to consult a medical provider before mixing any antidepressant medication with venlafaxine to avoid the risk of dangerous interactions.

Effexor And Wellbutrin

Effexor and bupropion may be used together for treating chronic recurrent major depression. However, mixing Wellbutrin and Effexor may cause a severe interaction with dangerous adverse reactions. The interaction between Wellbutrin and Effexor may increase the risk of developing seizures, especially in the elderly. It is recommended to avoid combination treatment venlafaxine and bupropion as the risks outweigh the benefits unless it is recommended by a doctor.

Effexor With Antidepressants

Trazodone And Effexor

What does venlafaxine do when it is mixed with Trazodone? A rare serious condition called serotonin syndrome might appear after mixing these drugs. The symptoms of serotonin syndrome may include:

  • Seizure
  • Confusion
  • Tremors
  • Hallucination
  • Racing heartbeat
  • Fever
  • Nausea
  • Excessive sweating
  • Shaking
  • High or low blood pressure
  • Blurred vision
  • Muscle spasm
  • Abdominal pain
  • Vomiting
  • Diarrhea
  • Coma
  • Death

Effexor And Zoloft

The two medications are effective in treating depression. However, there is a difference between Zoloft and Effexor in their mechanism of action. A doctor may prescribe both medications at the same time for refractory cases. The risk of severe interaction could occur when mixing Effexor and Zoloft. Dangerous serotonin toxicity is a common adverse reaction of this combination.

Effexor And Remeron

Mixing Effexor and Remeron is useful in the treatment of persistent depression. However, severe interaction may occur. This combination may cause sedation and weight gain. It is recommended to consult a healthcare provider before mixing venlafaxine with Remeron to avoid the risk of dangerous interaction effects.

Effexor And Prozac

In spite using of Prozac for withdrawal from Effexor due to its longer half-life, a dangerous interaction could occur if mix them together. Low Effexor dose with Prozac can cause constipation, urinary retention, blurred vision, and dry mouth. Severe risk of serotonin toxicity may occur if used together in higher doses. The use of Prozac and venlafaxine together should be done under the supervision of a healthcare provider.

Effexor And Lexapro

A combination of Effexor and Lexapro is beneficial for treating recurrent cases of depression. However, severe interaction can occur when they are co-administered. Toxic serotonin syndrome symptoms such as confusion, hallucination, and seizure may appear. It is advised not to mix Effexor with Lexapro medications without doctor consultation to avoid severe interaction effects.

Cymbalta And Effexor

Cymbalta and Effexor should not be used together as a severe interaction may occur. Such interaction can induce serotonin syndrome, resulting in nausea, altered consciousness, seizures, and death. It is not recommended to mix selective serotonin reuptake inhibitors with Cymbalta without doctor consultation.

Effexor With Stimulants

Interactions With Stimulants

A medical provider could prescribe Effexor with stimulant drugs for treating attention deficit hyperactivity disorder (ADHD). However, dangerous adverse reactions are possible after using them together. Nervousness, anxiety, and restlessness are common adverse reactions of mixing Effexor with any stimulant medication. Consulting a doctor before mixing these medications will help in avoiding the risk of dangerous reactions.

Effexor And Adderall

Mixing Effexor and Adderall may cause severe interactions besides decreasing the antidepressant effect of venlafaxine. Serious side effects are possible after using them together, such as increased anxiety and racing thoughts. Concurrent use of Adderall and Effexor is clinically contraindicated, as it could lead to increased serotonin levels due to potential inhibition of the CYP2D6 enzyme. It is highly recommended to avoid mixing amphetamine with venlafaxine without consultation with a doctor.

Effexor And Vyvanse

Co-administration of Effexor and lisdexamfetamine could also cause a severe interaction. Effexor may increase the stimulant effects of Vyvanse if they are taken together. As a result, there is a risk of side effects such as jitteriness, restlessness, and nervousness. A combination of Effexor and Vyvanse may also increase the risk of toxic serotonin syndrome.

Effexor With Benzodiazepines

Combinations With Benzodiazepines

Since Effexor is effective for the treatment of panic disorders, a doctor would prescribe venlafaxine with benzodiazepines to get higher effectiveness. Mixing venlafaxine with benzodiazepines could cause moderate interaction. Symptomatic hypotension is a common adverse reaction that appears if one takes venlafaxine and benzodiazepines together. A doctor may prescribe them both, but a person should avoid using these combinations without professional consultation.

Effexor And Xanax

A moderate interaction is possible if mix Effexor and Xanax. Taking them both together could increase the risk of side effects such as dizziness, confusion, drowsiness, difficulty concentrating, and drowsiness. Co-administration of Effexor with Xanax in the elderly causes impairment in judgment, thinking, and motor coordination. Avoid taking this combination while driving or operating hazardous machinery.

Effexor And Klonopin

Effexor and Klonopin combination may cause moderate interaction effects. Central nervous system depression and respiratory depression are common adverse reactions that could appear after co-administering these medications. It is recommended to consult a healthcare provider before mixing venlafaxine with clonazepam, especially for the elderly.

Effexor With Painkillers

Mixing With Painkillers

According to the U.S. National Library of Medicine, It is possible to use venlafaxine for neuropathic pain. As a result, a healthcare provider could prescribe venlafaxine for pain management with painkillers.

What painkillers can one take with venlafaxine?

  • A doctor can prescribe nonsteroidal anti-inflammatory drugs (NSAIDs) such as acetaminophen, ibuprofen, aspirin, and celecoxib with venlafaxine for pain relief. However, a combination of these medications increases the risk of bleeding, especially for the elderly or for patients who have hepatic or renal problems.
  • If someone tries to mix venlafaxine with opioids, the high risk of lethal serotonin syndrome may appear. For instance, tramadol may provide prophylactic antidepressant effects. A doctor can prescribe tramadol and Effexor for treating depression associated with chronic pain. However, severe interaction may occur if Effexor and tramadol are combined. Mixing venlafaxine and tramadol may increase the risk of lethal serotonin syndrome and seizures.

Effexor And Antipsychotic Medicines Together

Co-administration of Effexor and antipsychotics may help depressed patients who haven’t got better after an antidepressant monotherapy. Moderate interaction may occur when venlafaxine is mixed with antipsychotic medications. Such a combination may increase the risk of cardiac arrest and death. To avoid these fatal effects, it is always recommended to consult a medical provider before mixing venlafaxine with antipsychotics.

Abilify And Effexor

A moderate interaction could occur after mixing Abilify and Effexor. Concurrent use of both medications may increase adverse reactions such as drowsiness, confusion, and concentration problems. The use of Effexor and Abilify among the elderly could increase the risk of poor judgment and impaired thinking, so it is highly advised not to mix these medications without a doctor’s advice.

Effexor And Seroquel

Co-administration of Effexor and Seroquel can increase the risk of an irregular heartbeat and even may lead to death. Patients with congenital long QT syndrome or conduction abnormalities or electrolyte abnormalities are at high risk of this dangerous interaction. It is important not to mix Seroquel and Effexor without doctor consultation, to avoid the risk of fatal effects.

Venlafaxine With Anti-Epileptic Medications

Taking Venlafaxine With Anti-Epileptic Medications

A doctor may prescribe venlafaxine with antiepileptics for chronic pain. If combine venlafaxine in a dose of about 12.5 and 25mg/kg with antiepileptic, a moderate interaction could occur, which results in increasing the electroconvulsive threshold. As a result, venlafaxine may increase the risk of seizures. Lamotrigine is an epileptic drug that can be used with venlafaxine for treating bipolar depression. However, a combination of Effexor and Lamictal may cause significant complications. Concurrent use increases adverse reactions such as difficulty concentrating, impairment in judgment and thinking, and confusion. To avoid the risks of dangerous interactions, consult a doctor before mixing venlafaxine with any antiepileptic medication.

Combination With Appetite Suppressants

Is there is a relation between a mix of appetite suppressants with venlafaxine and weight gain? Yes, weight gain was reported as one of the venlafaxine warnings. Mixing venlafaxine with appetite suppressants could cause severe interaction and double weight gain. Concurrent use of venlafaxine and appetite suppressants may also result in weight loss, tachycardia, hypertension, and toxic serotonin syndrome. When taking Effexor and phentermine together, venlafaxine may increase the effects of phentermine. As a result, anxiety, restlessness, and nervousness may appear. It is highly recommended not to mix venlafaxine with appetite suppressants.

Mixing With Anti-Anxiety (Anxiolytic)

The use of venlafaxine and anti-anxiety drugs together may help in treating generalized anxiety disorder. A potential interaction could occur as a result of such a combination. However, such dangerous side effects such as seizures, high body temperature, agitation, increased reflexes, sweating, and dilated pupils are still possible. In spite of the use of buspirone as an antidote for nocturnal bruxism associated with venlafaxine, the concurrent use of these medications could cause severe interaction. Mixing Effexor and Buspar can increase serotonin levels in the body, leading to toxic serotonin syndrome.

Effexor And Marijuana

Some persons may use venlafaxine for reducing depression associated with cannabis. However, using venlafaxine could lead to an increase in cannabis use. Some recreational users may combine Effexor and marijuana to get high feelings.

Weed may increase Effexor levels in the blood and also potentiate its sedation effects. Mixing venlafaxine and weed may lead to dangerous interactions, which may be fatal. Respiratory depression, dizziness, vomiting, and central nervous system sedation could appear after combining Effexor and weed. It is recommended to avoid mixing Effexor and weed to prevent the possibility of hazardous interaction effects. Moreover, marijuana is illegal in several states of the U.S., so using may also lead to legal liability.

Effexor with Caffeine

Effexor And Caffeine

There are no dangerous interactions possible if mix venlafaxine with caffeine. However, drinking coffee may opposite the sedative effects of venlafaxine because of its CNS stimulant properties. According to a study published in the Journal of International Medical Research, caffeine consumption may antagonize the antinociceptive effect of venlafaxine. So, it is recommended to avoid taking Effexor and caffeine together as it may decrease venlafaxine efficacy.

Interactions With Food

Extended-release formulations of Effexor is usually taken with food. Food may decrease the rate but not the extent of absorption of venlafaxine. Grapefruits are cytochrome P450 1A2 and 3A4 inhibitors. As a result, there is a risk of a dangerous interaction if one consumes venlafaxine with grapefruit. Sleepiness, nausea, nervousness, and increased heart rate are possible after taking this drug with grapefruit juice.

Avoid Dangerous Interactions With Effexor

Many severe drug interactions with venlafaxine should be prevented and avoided: with Wellbutrin, Trazodone, Zoloft, Remeron, Vyvanse, Xanax, Benadryl, and many other drugs and substances. The most effective way to prevent severe consequences of interactions with venlafaxine is to consult a medical professional. Mixing any substance with venlafaxine should be made under the supervision of a doctor only, especially if women take Effexor while pregnant. Misusing Effexor or co-administering it with other drugs may also increase the chance of abuse and addiction development. If any signs of addiction are noticed, finding a rehab center for addicts to accelerate the recovery process is essential. Many addiction treatment options are available for different types of abuses caused by mixing venlafaxine with other medications.

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Published on: November 29th, 2019

Updated on: February 19th, 2020

About Author

Nena Messina, Ph.D.

Nena Messina is a specialist in drug-related domestic violence. She devoted her life to the study of the connection between crime, mental health, and substance abuse. Apart from her work as management at addiction center, Nena regularly takes part in the educational program as a lecturer.


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