warfarin, other anticoagulants, or other drugs known to affect platelet function may add to this risk For patients taking warfarin, carefully monitor coagulation indices when initiating, titrating, or discontinuing therapy Drug interactions overview Inhibitor of CYP2D6 Advise patients to avoid alcohol consumption while taking desvenlafaxine CYP2D6 substrates Desvenlafaxine increases peak plasma concentration and AUC of a drug primarily metabolized by CYP2D6 which may increase the risk of toxicity of the CYP2D6 substrates Drug-laboratory test interactions False-positive urine immunoassay screening tests for phencyclidine (PCP) and amphetamine reported in patients taking desvenlafaxine Confirmatory tests, such as gas chromatography/mass spectrometry, will distinguish desvenlafaxine from PCP and amphetamine Pregnancy Pregnancy H3 No published studies on desvenlafaxine in pregnant women; however published epidemiologic studies of pregnant women exposed to venlafaxine, the parent compound, have not reported a clear association with adverse developmental outcomes Exposure to SNRIs in mid-to-late pregnancy may increase the risk for preeclampsia, and exposure to SNRIs near delivery may increase the risk for postpartum hemorrhage Exposure to SNRIs or SSRIs in late pregnancy may lead to an increased risk for neonatal complications requiring prolonged hospitalization, respiratory support, and tube feeding; monitor neonates who were exposed to desvenlafaxine in the third trimester of pregnancy for drug discontinuation syndrome Pregnancy exposure registry Monitors pregnancy outcomes in women exposed to antidepressants during pregnancy Encourage patients to register by calling the National Pregnancy Registry for Antidepressants at 1-844-405-6185 Lactation Available limited data from published literature show low levels of desvenlafaxine in human milk, and have not shown adverse reactions in breastfed infants There are no data on the effects of desvenlafaxine on milk production Consider the developmental and health benefits of breastfeeding along with the mother’s clinical need for desvenlafaxine and any potential adverse effects on the breastfed child from desvenlafaxine or from the underlying maternal conditionPregnancy Categories A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk. B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available. Mechanism of Action Potent SNRI; major active metabolite of venlafaxine Absorption Bioavailability: 80% Peak plasma time: 7.5 hr Steady-state reached by 4-5 days Effect of food High-fat meal (800-1000 calories): Increased desvenlafaxine peak plasma concentration about 16% and had no effect on AUC Distribution Protein bound: 30% Vd: 3.4 L/kg Metabolism Primary: Conjugation (UDP-glucuronosyltransferase isoform mediated) Minor: CYP3A4 oxidative metabolism (N-demethylation) Enzymes inhibited: CYP2D6 (minimally) Elimination Half-life: 11 hr (prolonged in renal or hepatic dysfunction) Dialyzable: No Excretion Unchanged drug: Urine (45%) Metabolite: Urine (19% [glucuronide]; <5% [oxidative metabolite N,O-didesmethylvenlafaxine]) Oral Administration Take at about the same time each day with or without food Swallow tablets whole, with fluid; do not cut, crush, chew, or dissolve Avoid drinking alcohol while taking dose Storage Tablets: Store at 20-25ºC (68-77ºF); excursions permitted to 15-30ºC (59-86ºF) BRAND FORM. UNIT PRICE PILL IMAGE desvenlafaxine oral- 100 mg tabletdesvenlafaxine oral- 50 mg tabletCopyright © 2010 First DataBank, Inc.Print Patient Educationdesvenlafaxine oral DESVENLAFAXINE EXTENDED-RELEASE - ORAL (des-VEN-la-FAX-een) COMMON BRAND NAME(S): Pristiq WARNING: Antidepressant medications are used to treat a variety of conditions, including depression and other mental/mood disorders. These medications can help prevent suicidal thoughts/attempts and provide other important benefits. However, studies have shown that a small number of people (especially people younger than 25) who take antidepressants for any condition may experience worsening depression, other mental/mood symptoms, or suicidal thoughts/attempts. It is very important to talk with the doctor about the risks and benefits of antidepressant medication (especially for people younger than 25), even if treatment is not for a mental/mood condition.Tell the doctor right away if you notice worsening depression/other psychiatric conditions, unusual behavior changes (including possible suicidal thoughts/attempts), or other mental/mood changes (including new/worsening anxiety, panic attacks, trouble sleeping, irritability, hostile/angry feelings, impulsive actions, severe restlessness, very rapid speech). Be especially watchful for these symptoms when a new antidepressant is started or when the dose is changed. USES: Desvenlafaxine is used to treat depression. It may improve your mood, feelings of well-being, and energy level. Desvenlafaxine is known as a serotonin-norepinephrine reuptake inhibitor (SNRI). It works by helping to restore the balance of certain natural substances (serotonin and norepinephrine) in the brain. HOW TO USE: Read the Medication Guide and, if available, the Patient Information Leaflet provided by your pharmacist before you start taking desvenlafaxine and each time you get a refill. If you have any questions, ask your doctor or pharmacist.Take this medication by mouth with or without food as directed by your doctor, usually once daily. The dosage is based on your medical condition and response to treatment.Do not crush, chew, or dissolve this medication in water. Doing so can release all of the drug at once, increasing the risk of side effects. Swallow the tablets whole.To reduce your risk of side effects, your doctor may direct you to start this medication at a low dose and gradually increase your dose. Follow your doctor's instructions carefully. Do not increase your dose or use this drug more often or for longer than prescribed. Your condition will not improve any faster, and your risk of side effects will increase. Use this medication regularly to get the most benefit from it. To help you remember, use it at the same time each day.Keep taking this medication even if you feel well. Do not stop taking this medication without consulting your doctor. Some conditions may become worse when this drug is suddenly stopped. Also, you may experience symptoms such as mood swings, blurred vision, headache, tiredness, sleep changes, and brief feelings similar to electric shock. To prevent these symptoms while you are stopping treatment with this drug, your doctor may reduce your dose gradually. Consult your doctor or pharmacist for more details. Report any new or worsening symptoms right away.If you are switching from another antidepressant to desvenlafaxine, your doctor should slowly reduce the dose of your old antidepressant to prevent withdrawal reactions from the other antidepressant. Ask your doctor or pharmacist for more details.It may take several weeks before you get the full benefit of this medication. Tell your doctor if your condition does not improve or if it worsens. SIDE EFFECTS: See also Warning section.Drowsiness, dizziness, nausea, dry mouth, constipation, loss of appetite, weight loss, blurred vision, nervousness, trouble sleeping, or excessive sweating may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.This medication may raise your blood pressure. Check your blood pressure regularly and tell your doctor if the results are high.An empty tablet shell may appear in your stool. This effect is harmless because your body has already absorbed the medication.Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.Tell your doctor right away if you have any serious side effects, including: severe/pounding headache, shakiness (tremor), decreased interest in sex, changes in sexual ability, easy bleeding/bruising.Get medical help right away if you have any very serious side effects, including: cough that doesn't go away, shortness of breath, chest pain, black stools, vomit that looks like coffee grounds, eye pain/swelling/redness, widened pupils, vision changes (such as seeing rainbows around lights at night), seizures.This medication may increase serotonin and rarely cause a very serious condition called serotonin syndrome/toxicity. The risk increases if you are also taking other drugs that increase serotonin, so tell your doctor or pharmacist of all the drugs you take (see Drug Interactions section). Get medical help right away if you develop some of the following symptoms: fast heartbeat, hallucinations, loss of coordination, severe dizziness, severe nausea/vomiting/diarrhea, twitching muscles, unexplained fever, unusual agitation/restlessness.A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345. PRECAUTIONS: Before taking desvenlafaxine, tell your doctor or pharmacist if you are allergic to it; or to venlafaxine; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.Before using this medication, tell your doctor or pharmacist your medical history, especially of: personal or family history of psychiatric disorders (such as bipolar/manic-depressive disorder), personal or family history of suicide attempts, bleeding problems, personal or family history of glaucoma (angle-closure type), high blood pressure, heart problems (such as chest pain, heart failure, heart attack), history of stroke, high cholesterol, kidney disease, liver disease, seizure disorder, low sodium in the blood (hyponatremia).This drug may make you dizzy or drowsy or blur your vision. Alcohol or marijuana (cannabis) can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness or clear vision until you can do it safely. Avoid alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).Older adults may be more sensitive to the side effects of this drug, especially dizziness when standing. Older adults may also be more likely to develop a type of salt imbalance (hyponatremia), especially if they are taking "water pills" (diuretics). Dizziness and salt imbalance can increase the risk of falling. Older adults may also be at greater risk for bleeding while using this drug.Based on information for a similar drug (venlafaxine), children may be more sensitive to the side effects of this drug, especially loss of appetite and weight loss. Monitor height and weight in children who are taking this drug. Consult your doctor or pharmacist for more details.During pregnancy, this medication should be used only when clearly needed. It may harm an unborn baby. Also, babies born to mothers who have used this drug during the last 3 months of pregnancy may rarely develop withdrawal symptoms such as feeding/breathing difficulties, seizures, muscle stiffness, or constant crying. If you notice any of these symptoms in your newborn, tell the doctor promptly.Since untreated mental/mood problems (such as depression, anxiety, and panic attacks) can be a serious condition, do not stop taking this medication unless directed by your doctor. If you are planning pregnancy, become pregnant, or think you may be pregnant, immediately discuss with your doctor the benefits and risks of using this medication during pregnancy.This drug passes into breast milk and may have undesirable effects on a nursing infant. Consult your doctor before breast-feeding. DRUG INTERACTIONS: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.Some products that may interact with this drug are: other drugs that can cause bleeding/bruising (including antiplatelet drugs such as clopidogrel, NSAIDs such as ibuprofen/naproxen, "blood thinners" such as dabigatran/warfarin).Aspirin can increase the risk of bleeding when used with this medication. However, if your doctor has directed you to take low-dose aspirin for heart attack or stroke prevention (usually 81-162 milligrams a day), you should continue taking it unless your doctor instructs you otherwise. Ask your doctor or pharmacist for more details.Taking MAO inhibitors with this medication may cause a serious (possibly fatal) drug interaction. Avoid taking