Pristiq (Generic Desvenlafaxine)
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A small number of children, teenagers, and young adults (up to 24 years of age) who took antidepressants (‘mood elevators’) such as desvenlafaxine during clinical studies became suicidal (thinking about harming or killing oneself or planning or trying to do so). Children, teenagers, and young adults who take antidepressants to treat depression or other mental illnesses may be more likely to become suicidal than children, teenagers, and young adults who do not take antidepressants to treat these conditions. However, experts are not sure about how great this risk is and how much it should be considered in deciding whether a child or teenager should take an antidepressant. Children younger than 18 years of age should not normally take desvenlafaxine, but in some cases, a doctor may decide that desvenlafaxine is the best medication to treat a child’s condition.
You should know that your mental health may change in unexpected ways when you take desvenlafaxine or other antidepressants even if you are an adult over 24 years of age. You may become suicidal, especially at the beginning of your treatment and any time that your dose is increased or decreased. You, your family, or your caregiver should call your doctor right away if you experience any of the following symptoms: new or worsening depression; thinking about harming or killing yourself, or planning or trying to do so; extreme worry; agitation; panic attacks; difficulty falling asleep or staying asleep; aggressive behavior; irritability; acting without thinking; severe restlessness; or frenzied abnormal excitement. Be sure that your family or caregiver knows which symptoms may be serious so they can call the doctor if you are unable to seek treatment on your own.
Your healthcare provider will want to see you often while you are taking desvenlafaxine, especially at the beginning of your treatment. Be sure to keep all appointments for office visits with your doctor.
The doctor or pharmacist will give you the manufacturer’s patient information sheet (Medication Guide) when you begin treatment with desvenlafaxine. Read the information carefully and ask your doctor or pharmacist if you have any questions. You also can obtain the Medication Guide from the FDA website: http://www.fda.gov/Drugs/DrugSafety/ucm085729.htm.
No matter your age, before you take an antidepressant, you, your parent, or your caregiver should talk to your doctor about the risks and benefits of treating your condition with an antidepressant or with other treatments. You should also talk about the risks and benefits of not treating your condition. You should know that having depression or another mental illness greatly increases the risk that you will become suicidal. This risk is higher if you or anyone in your family has or has ever had bipolar disorder (mood that changes from depressed to abnormally excited) or mania (frenzied, abnormally excited mood) or has thought about or attempted suicide. Talk to your doctor about your condition, symptoms, and personal and family medical history. You and your doctor will decide what type of treatment is right for you.
Why is this medication prescribed?
Desvenlafaxine is used to treat depression. Desvenlafaxine is in a class of medications called selective serotonin and norepinephrine reuptake inhibitors (SNRIs). It works by increasing the amounts of serotonin and norepinephrine, natural substances in the brain that help maintain mental balance.
How should this medicine be used?
Desvenlafaxine comes as an extended-release (long-acting) tablet to take by mouth. It is usually taken once a day with or without food. Take desvenlafaxine at around the same time every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take desvenlafaxine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Swallow the tablets whole with plenty of water; do not split, chew, crush, or dissolve them.
Desvenlafaxine controls depression, but does not cure it. It may take several weeks before you feel the full benefit of desvenlafaxine. Continue to take desvenlafaxine even if you feel well. Do not stop taking desvenlafaxine without talking to your doctor. Your doctor will probably decrease your dose gradually. If you suddenly stop taking desvenlafaxine, you may experience withdrawal symptoms such as dizziness; confusion; nausea; headache; ringing in the ears; irritability; aggressive behavior; inability to control emotions; frequent mood changes; abnormally excited, difficulty falling asleep or staying asleep, diarrhea, anxiety; extreme tiredness; unusual dreams; seizures; sweating; uncontrollable shaking of a part of the body; blurred vision; or pain, burning or tingling in the hands or feet. Tell your doctor if you experience any of these symptoms while you are decreasing your dose of desvenlafaxine or soon after you stop taking desvenlafaxine.
Other uses for this medicine
Desvenlafaxine is also sometimes used to treat hot flashes (hot flushes; sudden strong feelings of heat and sweating) in women who have experienced menopause (‘change of life’; the end of monthly menstrual periods). Talk to your doctor about the risks of using this medication for your condition.
This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.
What special precautions should I follow?
Before taking desvenlafaxine,
- Tell your doctor and pharmacist if you are allergic to desvenlafaxine, venlafaxine (Effexor), any other medications, or any of the ingredients in desvenlafaxine tablets. Ask your pharmacist or check the Medication Guide for a list of the ingredients.
- Tell your doctor if you are taking a monoamine oxidase (MAO) inhibitor, such as isocarboxazid (Marplan), linezolid (Zyvox), methylene blue, phenelzine (Nardil), selegiline (Emsam, Zelapar), and tranylcypromine (Parnate), or if you have stopped taking one of these medications within the past 14 days. Your doctor will probably tell you that you should not take desvenlafaxine. If you stop taking desvenlafaxine, your doctor will tell you that you should wait at least 7 days before you start to take an MAO inhibitor.
- You should know that desvenlafaxine is very similar to another SNRI, venlafaxine (Effexor). You should not take these medications together.
- Tell your doctor and pharmacist what other prescription and nonprescription medications or vitamins you are taking or plan to take. Be sure to mention any of the following: amphetamines such as amphetamine (in Adderall, in Mydayis), dextroamphetamine (Dexedrine, in Adderall), and methamphetamine (Desoxyn); anticoagulants (‘blood thinners’) such as warfarin (Coumadin, Jantoven); aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Advil, Motrin) and naproxen (Aleve, Naprosyn); atomoxetine (Straterra); buspirone; dextromethorphan (found in many cough medications; in Nuedexta); diuretics (‘water pills’); fentanyl (Actiq, Duragesic, Fentora, Subsys); ketoconazole; lithium (Lithobid); medications for anxiety, mental illness, or seizures; medications for migraine such as almotriptan, eletriptan (Relpax), frovatriptan (Frova), naratriptan (Amerge), rizatriptan (Maxalt), sumatriptan (Imitrex), and zolmitriptan (Zomig); metoprolol (Lopressor, Toprol XL); midazolam; nebivolol (Bystolic); nefazodone; perphenazine; sedatives; selective serotonin reuptake inhibitors (SSRIs) such as citalopram (Celexa), escitalopram (Lexapro), fluoxetine (Prozac, in Symbyax), fluvoxamine (Luvox), paroxetine (Paxil), and sertraline (Zoloft); other SNRIs such as duloxetine (Cymbalta); sleeping pills; tolterodine (Detrol); tramadol (Ultram); tranquilizers; and tricyclic antidepressants such as amitriptyline, amoxapine, clomipramine (Anafranil), desipramine (Norpramin), doxepin (Silenor), imipramine (Tofranil), nortriptyline (Pamelor), protriptyline, and trimipramine. Your doctor may need to change the doses of your medications or monitor you carefully for side effects. Many other medications may also interact with desvenlafaxine, so be sure to tell your doctor about all the medications you are taking, even those that do not appear on this list.
- Tell your doctor what herbal products and nutritional supplements you are taking, especially St. John’s wort and tryptophan.
- Tell your doctor if you drink or have ever drunk large amounts of alcohol or use or have ever used street drugs or have ever overused prescription medications. Also tell your doctor if you have or have ever had bleeding problems; a stroke; high blood pressure; high cholesterol or triglycerides (fats in the blood); seizures; low sodium levels in the blood; or heart, kidney, or liver disease.
- Tell your doctor if you are pregnant, especially if you are in the last few months of your pregnancy, or if you plan to become pregnant or are breast-feeding. If you become pregnant while taking desvenlafaxine, call your doctor. Desvenlafaxine may cause problems in newborns following delivery if it is taken during the last months of pregnancy.
- If you are having surgery, including dental surgery, tell the doctor or dentist that you are taking desvenlafaxine.
- You should know that desvenlafaxine may make you drowsy and may affect your judgment, thinking, and movements. Do not drive a car or operate machinery until you know how this medication affects you.
- Ask your doctor about the safe use of alcoholic beverages while you are taking desvenlafaxine. Alcohol can make the side effects from desvenlafaxine worse.
- You should know that desvenlafaxine may cause high blood pressure. You should have your blood pressure checked before starting treatment and regularly while you are taking this medication.
- You should know that in older adults, desvenlafaxine may cause dizziness, lightheadedness, and fainting when you get up too quickly from a lying position. To avoid this problem, get out of bed slowly, resting your feet on the floor for a few minutes before standing up.
- You should know that desvenlafaxine may cause angle-closure glaucoma (a condition where the fluid is suddenly blocked and unable to flow out of the eye causing a quick, severe increase in eye pressure which may lead to a loss of vision). Talk to your doctor about having an eye examination before you start taking this medication. If you have nausea, eye pain, changes in vision, such as seeing colored rings around lights, and swelling or redness in or around the eye, call your doctor or get emergency medical treatment right away.
What special dietary instructions should I follow?
Unless your doctor tells you otherwise, continue your normal diet.
What should I do if I forget a dose?
Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.
What side effects can this medication cause?
Desvenlafaxine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- Loss of appetite
- Dry mouth
- Extreme tiredness
- Unusual dreams
- Difficulty falling asleep or staying asleep
- Uncontrollable shaking of a part of the body
- Pain, burning, numbness, or tingling in part of the body
- Enlarged pupils (black circles in the centers of the eyes)
- Sexual problems in males; decreased sex drive, inability to get or keep an erection, or delayed or absent ejaculation
- Sexual problems in females; decreased sex drive, or delayed orgasm or unable to have an orgasm
- Difficulty urinating
Some side effects can be serious. If you experience any of these symptoms or those listed in the IMPORTANT WARNING or SPECIAL PRECAUTIONS section, call your doctor immediately:
- Swelling of the face, throat, tongue, lips, eyes, hands, feet, ankles, or lower legs
- Difficulty swallowing or breathing
- Fast heartbeat
- Chest, arm, back, neck, or jaw pain
- Coma (loss of consciousness for a period of time)
- Fever, sweating, confusion, fast or irregular heartbeat, severe muscle stiffness or twitching, agitation, hallucinations, loss of coordination, nausea, vomiting, or diarrhea
- Unusual bleeding or bruising
- Small red or purple dots on the skin
- Difficulty concentrating
- Memory problems
- Increased falls
Desvenlafaxine may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration’s (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).
What should I know about storage and disposal of this medication?
Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).
Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA’s Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.
It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org
In case of emergency/overdose
In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at https://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can’t be awakened, immediately call emergency services at 911.
Symptoms of overdose may include:
- Agitation, hallucinations, fever, sweating, confusion, fast heartbeat, shivering, severe muscle stiffness or twitching, loss of coordination, nausea, vomiting, or diarrhea
- Fast, slow, or irregular heartbeat
- Increased size of the pupil (black center of the eye)
- Muscle pain or weakness
What other information should I know?
Keep all appointments with your doctor and the laboratory.
The extended-release tablet does not dissolve in the stomach after swallowing. It slowly releases the medicine as it passes through your digestive system. You may notice the tablet coating in the stool. This is normal and does not mean that you did not receive the complete dose of medication.
Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.