Pristiq (Desvenlafaxine succinate)

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.

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 Pristiq® and medicines used to treat migraine headaches known as 5-hydroxytryptamine receptor agonist (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 SNRI/ SSRI or a triptan. Before you take Pristiq® 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.

Brand and Generic Names:

Brand name = Pristiq®

Tablets (extended release): 50 mg, 100 mg

Generic name = Desvenlafaxine Succinate

What is Pristiq® and what does it treat?

Desvenlafaxine 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). Desvenlafaxine is approved for the treatment of Major Depressive Disorder (MDD). Other SNRIs are FDA approved for various anxiety disorders (e.g. Generalized Anxiety Disorder, Panic Disorder). While desvenlafaxine has not been approved for these disorders, it is sometimes used to treat such conditions.
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.

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

After starting desvenlafaxine, 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 usually requires long-term treatment to help prevent the return of depressive symptoms. Only your healthcare provider can determine the length of desvenlafaxine treatment that is right for you.

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

Stopping desvenlafaxine 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 (e.g. excessive buying sprees).

Are there specific concerns about Pristiq® and pregnancy?

If you are pregnant or are planning to become pregnant, it is very important to discuss the risks and benefits of taking desvenlafaxine with your provider. The FDA has classified desvenlafaxine 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 desvenlafaxine 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 desvenlafaxine) will pass into the breast milk. The concentrations in breast milk are generally quite low with desvenlafaxine 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 Pristiq®?

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 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 Pristiq®?

Desvenlafaxine may be taken with food to minimize stomach upset.
Desvenlafaxine is usually taken once daily at the same time each day. Swallow the tablet whole with plenty of fluids. Do not divide, cut, chew or crush the tablet.
While the dose usually ranges from 50 mg to 400 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 Pristiq®?

If you miss a dose of desvenlafaxine, 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 Pristiq®?

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 Pristiq®?

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 Pristiq®?

Common: Side effects with desvenlafaxine 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 desvenlafaxine 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. Desvenlafaxine has been associated with an increase in blood pressure as well. Patients taking desvenlafaxine should have their blood pressure checked regularly and patients with preexisting high blood pressure should have their blood pressure under control before starting desvenlafaxine.

Rare: Other side effects which may occur infrequently with desvenlafaxine 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 Pristiq® for long periods of time?

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

What other drugs may interact with Pristiq®?

Desvenlafaxine 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 desvenlafaxine is used with 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®).

The concentration of desvenlafaxine may be increased by ketoconazole. Adjustment of desvenlafaxine dose may be required if side effects occur.

The concentration of desipramine and possibly other tricyclic antidepressants may be increased when used in combination with desvenlafaxine. Decreasing the dose of tricyclic antidepressants may be necessary to avoid adverse effects or toxicity.

Patients receiving warfarin therapy should be carefully monitored when desvenlafaxine is initiated or discontinued. Changes in bloodwork as well as increased bleeding have been reported when medications like desvenlafaxine are 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 Pristiq® to work?

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.

Written by Wilfred W. Acholonu, Jr., Pharm.D, BCPP
(February 2009)

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

For further information. Please contact the pharmaceutical company listed below.

Wyeth

5 Giralda Farms

Madison, NJ 07940

800-934-5556

www.wyeth.com

Free or low-cost medications provided by pharmaceutical companies

Some pharmaceutical companies offer medication assistance programs to low-income individuals and families. These programs typically require a doctor’s consent and proof of financial status. They may also require that you have either no health insurance, or no prescription drug benefit through your health insurance. Please contact the pharmaceutical company directly for specific eligibility requirements and application information.

Pristiq Rx Assistance Program: Online information