|  |

|

Effexor (venlafaxine)

---

FDA ALERT [07/2006] – Potentially Life- Threatening Serotonin Syndrome When Used With Triptan Medicines

A life-threatening condition called serotonin syndrome can happen when medicines called selective serotonin reuptake inhibitors (SSRIs), such as Prozac®, or serotonin norepinephrine reuptake inhibitors (SNRIs) such as Effexor® and medicines used to treat migraine headaches  known as 5-hydroxytryptamine receptor agonists (also known as “triptans” e.g. sumatriptan (Imitrex®) are used together.  Signs and symptoms of serotonin syndrome may include: restlessness, hallucinations, loss of coordination, fast heart beat, increased body temperature, fast changes in blood pressure, overactive reflexes, diarrhea, nausea, vomiting and coma.

Serotonin syndrome may be more likely to occur when starting or increasing the dose of an SSRI/SNRI or a triptan.  Before you take Effexor® and a triptan together, talk to your healthcare professional.  If you must take these medicines together, be aware of the possibility of serotonin syndrome, and get medical care right away if you think serotonin syndrome is happening to you.

This information reflects the FDA’s current analysis of data available to FDA concerning this drug

FDA ALERT 05/2007: Suicidal Thoughts or Actions in Children and Adults

Depression and certain other psychiatric disorders are themselves associated with increases in the risk of suicide.  Patients with major depressive disorder (MDD), both adult and pediatric, may experience worsening of their depression and/or the emergence of suicidal ideation and behavior (suicidality) or unusual changes in behavior, whether or not they are taking antidepressant medications.  This risk may persist until significant remission occurs.

In short-term studies, antidepressants increased the risk of suicidality in children, adolescents and young adults when compared to placebo.  Taking antidepressants may increase suicidality in about 1 out of 50 people 18 years or younger.  Short-term studies did not show an increase in the risk of suicidality with antidepressants compared to placebo in adults beyond age 24.

Patients, their families and caregivers should be alert to the emergence of anxiety, restlessness, irritability, aggressiveness and insomnia.  If these symptoms emerge, they should be reported to the patient’s prescriber or health care professional.  All patients being treated with antidepressants for any indication should watch for and notify their health care provider for worsening symptoms, suicidality and unusual changes in behavior, especially during the first few months of treatment.

This information reflects the FDA’s current analysis of data available to FDA concerning this drug.

---

Brand/Generic Names

• Brand name: Effexor^®, Effexor XR^®

Tablets (immediate release): 25 mg, 37.5 mg, 50 mg, 75 mg, 100 mg

Capules (extended release):  37.5 mg, 75 mg , 150 mg

• Generic name: Venlafaxine

Tablets (immediate release): 25 mg, 37.5 mg, 50 mg, 75 mg, 100 mg

Tablets (extended release): 37.5 mg, 75 mg, 150 mg, 225 mg

What is Effexor® and what does it treat?

Venlafaxine is an antidepressant medication that works in the brain on the neurotransmitters serotonin and norepinephrine.  It belongs to a class of medication known as Serotonin Norepinephrine Reuptake Inhibitors (SNRIs).  Venlafaxine is approved for the treatment of Major Depressive Disorder (MDD), Generalized Anxiety Disorder (GAD), panic disorder and social anxiety disorder (social phobia).

Major Depression occurs when a person experiences at least five symptoms of depression, one of which must be either sad or depressed mood, or loss of interest in most activities. Other symptoms include changes in sleep (usually poor sleep); changes in appetite (usually decreased); loss of energy; feeling worthless/guilty/ hopeless/ helpless; psychomotor agitation or retardation (i.e. thoughts/movements speeding up or slowing down); difficulty concentrating; and thoughts of death (suicidal thinking). These symptoms must be present for a minimum of two weeks to satisfy the diagnosis of MDD.

GAD occurs when a person experiences excessive anxiety or worry for at least six months along with restlessness, fatigue, difficulty concentrating, irritability, muscle tension or sleep disturbance.

Panic Disorder occurs when a person experiences unexpected and repeated episodes of intense fear along with physical symptoms including chest pain, shortness of breath, heart palpitations, sweating, dizziness, and nausea.

Social Anxiety Disorder is an anxiety disorder in which a person experiences extreme fear in situations where they have to meet new people.  The person may have physical symptoms in social situations (e.g. blushing, sweating, shaking, dry mouth, palpitations) and commonly tries to avoid social settings.

What is the most important information I should know about Effexor®?

After starting venlafaxine, symptoms gradually decrease over a period of weeks.  Sleep and other physical symptoms may improve before there is noticeable improvement in mood or interest in activities.  Once symptoms are under control, MDD and other disorders venlafaxine is used to treat usually require long-term treatment to help prevent the return of symptoms.  Only your healthcare provider can determine the length of venlafaxine treatment that is right for you.

Do not stop taking venlafaxine or change your dose without talking to with your healthcare provider first.

Stopping venlafaxine abruptly may result in one or more of the following withdrawal symptoms: irritability, nausea, dizziness, vomiting, nightmares, headache and paresthesias (prickling, tingling sensation on the skin).

Because depression is also a part of Bipolar illness, people who take antidepressants may be at risk for "switching" from depression into mania. Symptoms of mania include "high" or irritable mood, very high self esteem, decreased need for sleep, pressure to keep talking, racing thoughts, being easily distracted, frequently involved in activities with a large risk for bad consequences (for example, excessive buying sprees).

Are there specific concerns about Effexor® and pregnancy?

If you are pregnant or are planning to become pregnant, it is very important to discuss the risks and benefits of taking venlafaxine with your provider. The FDA has classified venlafaxine as Category C in regards to pregnancy risk. This means that there have not been well-controlled studies in humans examining safety or that animal studies have demonstrated adverse effects to the developing fetus.

The benefits of venlafaxine in pregnancy may still be greater than the potential risks. For instance, if depression is left untreated during pregnancy, there is a high risk for poor prenatal care and premature delivery, and the babies may exhibit developmental delays in speech, intelligence, and socialization skills. Women who stop their antidepressants after learning of a pregnancy are five times more likely to relapse than pregnant women who continue their antidepressant.   Women who suffer with depression during their pregnancy are much more likely to become depressed postpartum as well.

As the risk for relapse or worsening depressive symptoms varies greatly among women during pregnancy, the decision to treat with antidepressants must be made on an individual basis. This decision is best made following thoughtful discussion with a trusted and informed health professional.

Regarding breast-feeding, it is believed that virtually all antidepressants (including venlafaxine) will pass into the breast milk. The concentrations in breast milk are generally quite low with venlafaxine even at higher doses and it would not be expected to cause adverse effects in babies. However, breastfeeding mothers should monitor their infants for behavioral side effects and adequate growth.

What should I discuss with my healthcare provider before taking Effexor®?

• The most bothersome symptoms of your condition and how often these have occurred in the past
• If you have thoughts of suicide
• Medications you have taken in the past for your condition, whether they were effective or caused any adverse effects
• Any medical problems that you have especially high blood pressure
• Any medication allergies you have
• All other medications and nutritional/herbal supplements you are currently taking
• If you are pregnant, plan to become pregnant, or are breast-feeding
• Use of alcohol or recreational drugs (if applicable)

How should I take Effexor®?

Venlafaxine may be taken with food to minimize stomach upset.

Venlafaxine immediate release tablets are usually taken two times per day.

Venlafaxine extended release capsules or extended release tablets are usually taken once daily at the same time each day.  Swallow the capsule/tablet whole with plenty of fluids. Do not divide, cut, chew, crush, or place the capsules in water. Alternatively, with capsules, the dose may be administered by carefully opening the capsule and sprinkling the entire contents on a spoonful of applesauce. This drug/food mixture should be swallowed immediately without chewing and followed with a glass of water to ensure complete swallowing of the pellets 

While the total daily dose usually ranges from 37.5 mg to 225 mg, your healthcare provider will determine the dose that is right for you based upon your response.

What happens if I miss a dose of Effexor®?

If you miss a dose of venlafaxine, take it as soon as you remember unless it is close to when your next dose is due. If it is close to your next dose, wait until then to take the medication and skip the missed dose. Do not double your next dose or take more than your prescribed dose.

What should I avoid while taking Effexor®?

Avoid drinking alcohol or using illegal drugs while you are taking antidepressant medications because the beneficial effects of the medication may be decreased and adverse effects may be increased (e.g. sedation).

What happens if I overdose with Effexor®?

If an overdose occurs, whether intentional or accidental, immediate medical attention may be necessary.  Call your doctor or emergency medical service (911).  You may also contact the poison control center (1-800-222-1222).

Symptoms of overdose include drowsiness, nausea, vomiting, abdominal pain, tremor, slow heart rate, and seizures. A specific antidote does not exist.

What are the possible side effects of Effexor®?

Common:  Side effects with venlafaxine are generally mild and are similar to those reported with other SNRI antidepressants.  The most commonly reported side effects are nausea, diarrhea, headache, anxiety, dry mouth, insomnia, increased sweating, restlessness, sleepiness, yawning, flatulence, tremor, weight loss or gain, and dizziness.  If you experience side effects after starting venlafaxine they will often improve over the first week or two as you continue to take the medication.  Sexual side effects such as problems with orgasm or ejaculatory delay may also occur, and often do not diminish over time.

Venlafaxine has been associated with an increase in blood pressure as well.  Patients taking venlafaxine should have their blood pressure checked regularly and patients with preexisting high blood pressure should have their blood pressure under control before starting venlafaxine.

Rare:  Other side effects which may occur infrequently with venlafaxine include increased heart rate, low blood pressure, increased salivation, irregular menstrual cycle, increased frequency of urination, changes in taste, increased liver enzymes, increased bleeding (e.g. gums may bleed more easily), low sodium, and teeth grinding.

Are there any risks for taking Effexor® for long periods of time?

To date, there are no known neurotoxic or permanent side effects associated with long term use of venlafaxine.  It is a safe and effective medication when used as directed.

What other drugs may interact with Effexor®?

Venlafaxine should not be taken with or within two weeks of taking monoamine oxidase inhibitors (MAOIs).  These include phenelzine (Nardil®), tranylcypromine (Parnate®), isocarboxazid (Marplan®) and selegiline (Emsam®).

Although rare, there is an increased risk of serotonin syndrome when citalopram is used with other medications that increase serotonin activity such as other antidepressants; migraine medications called “triptans” (e.g. Imitrex®); the analgesics tramadol (Ultram®) or meperidine (Demerol®); and the antibiotic linezolid (Zyvox®).

Patients receiving warfarin therapy should be carefully monitored when venlafaxine is initiated or discontinued. Changes in bloodwork as well as increased bleeding have been reported when venlafaxine is co-administered with warfarin (Coumadin®), aspirin or pain relievers known as “NSAIDS” (Non-Steroidal Anti-inflammatory Agents).

Always let your doctor know what other prescription, over-the-counter, and herbal medications you are taking.

How long does it take for Effexor® to work?

When venlafaxine is used for depression, disturbances in sleep, energy, or appetite may show some improvement within the first 1-2 weeks and can be an important early signal that the medication is working. Other symptoms such as depressed mood or lack of interest in activities may take 4-6 weeks before improvement is evident.

Like other medications used for anxiety disorders (e.g. panic disorder, GAD and social anxiety disorder) venlafaxine may take several weeks before it is fully effective.  It is important to give the medication sufficient time before judging whether or not it will work for a given person.

 

Updated by
Ben Dishman, Pharm.D., BCPP
(March 2009)

 

 NAMI wishes to thank the College of Psychiatric and Neurologic Pharmacists  for producing this fact sheet.

Reviewed by Dr. Ken Duckworth, NAMI Medical Director

For further information please contact the pharmaceutical company listed below.

Wyeth

500 Arcola Rd. Collegeville, PA 19426

610-902-1200

www.wyeth.com

 

Free or low-cost medications provided by pharmaceutical companies

Effexor Rx Assistance Program: 1- 800-568-9938

|  |

|

---

Join NAMI today!

When you become a member of NAMI, you become part of America's largest grassroots organization dedicated to improving the lives of persons living with serious mental illness. And now you can join online.