Pristiq 100mg Tablets

Desvenlafaxine is a selective serotonin and norepinephrine reuptake inhibitor (SNRI). It enhances the neurotransmission of serotonin and norepinephrine in the central nervous system by blocking their reuptake pumps, leading to increased concentrations of these neurotransmitters in the synaptic cleft. This action is believed to be responsible for its antidepressant effects.

Urgent Side Effects: Seek Medical Help Right Away

Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor or seek immediate medical attention:

Signs of an allergic reaction: rash, hives, itching, red, swollen, blistered, or peeling skin (with or without fever), wheezing, tightness in the chest or throat, difficulty breathing, swallowing, or talking, unusual hoarseness, or swelling of the mouth, face, lips, tongue, or throat.
Signs of low sodium levels: headache, trouble focusing, memory problems, confusion, weakness, seizures, or changes in balance.
Signs of bleeding: vomiting or coughing up blood, vomit that resembles coffee grounds, blood in the urine, black, red, or tarry stools, bleeding from the gums, abnormal vaginal bleeding, unexplained bruises or bruises that enlarge, or uncontrollable bleeding.
Signs of high blood pressure: severe headache or dizziness, fainting, or changes in vision.
Signs of lung or breathing problems: shortness of breath or other breathing difficulties, cough, or fever.
Chest pain or pressure.
Seizures.
Hallucinations (seeing or hearing things that are not there).
Sex problems, including decreased interest in sex, difficulty having an orgasm, ejaculation problems, or trouble getting or maintaining an erection. If you have concerns, discuss them with your doctor.
A potentially life-threatening condition called serotonin syndrome may occur, especially if you are taking certain other medications. Seek immediate medical attention if you experience agitation, changes in balance, confusion, hallucinations, fever, rapid or abnormal heartbeat, flushing, muscle twitching or stiffness, seizures, shivering or shaking, excessive sweating, severe diarrhea, stomach upset, or vomiting, or a severe headache.

Other Possible Side Effects

Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it is essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other symptoms that bother you or persist, contact your doctor or seek medical attention:

Dizziness, drowsiness, fatigue, or weakness.
Upset stomach or vomiting.
Constipation.
Dry mouth.
Difficulty sleeping.
Decreased appetite.
Sweating.
Shakiness.

This is not an exhaustive list of possible side effects. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.

Before Taking This Medication: Important Information to Share with Your Doctor

It is essential to inform your doctor about the following conditions and situations to ensure safe treatment:

Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Describe the allergic reactions you experienced.
A diagnosis of narrow-angle glaucoma.
High blood pressure.
Current or recent use of certain medications, including:
+ Linezolid or methylene blue.
+ Drugs for depression or Parkinson's disease taken within the last 14 days, such as isocarboxazid, phenelzine, tranylcypromine, selegiline, or rasagiline, as they may cause very high blood pressure.
Use of another medication that contains the same active ingredient as this drug.
Use of a similar medication, if you are unsure, consult your doctor or pharmacist.

This list is not exhaustive, and it is crucial to disclose all your medications, including prescription and over-the-counter drugs, natural products, and vitamins, as well as any health problems, to your doctor and pharmacist. They will help determine if it is safe to take this medication with your other treatments and health conditions. Never start, stop, or adjust the dosage of any medication without consulting your doctor.

Important Information About Your Medication

It is crucial that you inform all of your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. This will help ensure that you receive the best possible care.

When to Expect Results and Precautions

It may take several months to experience the full effects of this medication. In the meantime, be cautious when engaging in activities that require your full attention, such as driving, until you understand how this medication affects you. To minimize the risk of dizziness or fainting, stand up slowly after sitting or lying down, and be careful when navigating stairs.

Stopping the Medication and Potential Side Effects

Do not stop taking this medication abruptly without consulting your doctor, as this may increase your risk of severe and long-lasting side effects. If you need to discontinue the medication, your doctor will provide guidance on how to do so safely. Be sure to discuss any new or worsening symptoms with your doctor.

Monitoring Your Health

Regular blood pressure checks are essential while taking this medication, as it may cause high blood pressure. Your doctor will advise you on the frequency of these checks.

Interactions with Other Substances

Avoid consuming alcohol while taking this medication. Additionally, consult your doctor before using marijuana, cannabis, or prescription or over-the-counter medications that may cause drowsiness.

Potential Risks and Complications

This medication may increase your risk of bleeding, which can be life-threatening in some cases. Discuss this risk with your doctor. Some individuals may be more prone to eye problems while taking this medication. Your doctor may recommend an eye exam to assess your risk. If you experience eye pain, changes in vision, or swelling and redness in or around the eye, contact your doctor immediately.

Low Blood Sodium Levels and High Cholesterol

This medication may cause low blood sodium levels, which can be fatal in severe cases. Discuss this risk with your doctor. High cholesterol has also been reported in individuals taking this medication. If you have concerns, consult your doctor.

Lab Tests and Medication Interactions

This medication may affect certain lab tests. Inform all of your healthcare providers and lab personnel that you are taking this medication.

What to Expect

You may notice what appears to be a tablet in your stool. This is a normal occurrence and not a cause for concern. If you have questions, discuss them with your doctor.

Special Considerations

If you are 65 or older, use this medication with caution, as you may be more susceptible to side effects. Pregnant or breastfeeding women should discuss the benefits and risks of this medication with their doctor. Taking this medication in the third trimester of pregnancy may increase the risk of bleeding after delivery and potentially cause health problems in the newborn. Breastfeeding women should also discuss any potential risks to their baby with their doctor.

• Monoamine Oxidase Inhibitors (MAOIs) (concurrent use or within 14 days of stopping MAOI or starting MAOI within 7 days of stopping desvenlafaxine)

• Other serotonergic drugs (e.g., SSRIs, other SNRIs, triptans, fentanyl, lithium, tramadol, tryptophan, buspirone, St. John's Wort) - increased risk of serotonin syndrome
• Anticoagulants (e.g., warfarin) and antiplatelet agents (e.g., aspirin, NSAIDs) - increased risk of bleeding
• Drugs that prolong the QT interval - theoretical risk of QT prolongation

• CNS depressants (e.g., alcohol, benzodiazepines, opioids) - additive CNS depression
• Drugs that increase blood pressure or heart rate (e.g., sympathomimetics) - additive effects
• CYP2D6 substrates (e.g., metoprolol, atomoxetine) - desvenlafaxine is a weak inhibitor of CYP2D6, potentially increasing exposure of these drugs

• Not available

• Worsening depression
• New or worsening anxiety
• Agitation
• Panic attacks
• Insomnia
• Irritability
• Hostility
• Impulsivity
• Akathisia (psychomotor restlessness)
• Hypomania
• Mania
• Unusual changes in behavior
• Dizziness
• Nausea
• Headache
• Sweating
• Dry mouth
• Constipation
• Sexual dysfunction
• Blurred vision
• Tremor
• Serotonin syndrome symptoms (agitation, hallucinations, delirium, coma, tachycardia, labile blood pressure, dizziness, sweating, flushing, hyperthermia, tremor, rigidity, myoclonus, hyperreflexia, incoordination, GI symptoms)
• Withdrawal symptoms upon discontinuation (dizziness, headache, nausea, diarrhea, insomnia, irritability, anxiety, paresthesia, fatigue, flu-like symptoms)

Use during pregnancy should be considered only if the potential benefit justifies the potential risk to the fetus. Exposure to SNRIs late in the third trimester has been associated with complications in neonates requiring prolonged hospitalization, respiratory support, and tube feeding. These complications can include respiratory distress, cyanosis, apnea, seizures, temperature instability, feeding difficulty, vomiting, hypoglycemia, hypotonia, hypertonia, hyperreflexia, tremor, jitteriness, irritability, and constant crying. Persistent Pulmonary Hypertension of the Newborn (PPHN) has been reported with SSRI/SNRI exposure during pregnancy.

Desvenlafaxine is excreted into human breast milk. The decision to breastfeed should consider the developmental and health benefits of breastfeeding, the mother’s clinical need for desvenlafaxine, and any potential adverse effects on the breastfed infant from desvenlafaxine or from the underlying maternal condition. Monitor breastfed infants for sedation, poor feeding, and poor weight gain.

Safety and efficacy have not been established in pediatric patients for Major Depressive Disorder. Antidepressants, including desvenlafaxine, increase the risk of suicidal thoughts and behavior in children, adolescents, and young adults (see Black Box Warning). Use in this population is generally not recommended unless benefits clearly outweigh risks and under close supervision.

No overall differences in safety or effectiveness were observed between geriatric and younger patients, but greater sensitivity of some older individuals cannot be ruled out. Elderly patients may be at increased risk for hyponatremia and falls. Dosage adjustments may be necessary based on renal function, which commonly declines with age. Start with lower doses and monitor closely.

• Desvenlafaxine is the active metabolite of venlafaxine, offering similar efficacy with potentially simpler pharmacokinetics (less CYP interaction).
• Always counsel patients on the importance of not abruptly discontinuing desvenlafaxine due to the risk of significant withdrawal symptoms (SNRI discontinuation syndrome). Taper slowly over several weeks.
• Monitor blood pressure regularly, especially during the initial weeks of treatment and with dose increases, as SNRIs can cause sustained hypertension.
• Be vigilant for symptoms of serotonin syndrome, especially when co-administered with other serotonergic agents.
• Advise patients that the tablet matrix may be visible in the stool; this is normal and does not mean the medication was not absorbed.
• Consider the risk of activating mania/hypomania in patients with undiagnosed bipolar disorder; screen for bipolar disorder before initiating antidepressant therapy.

• Other SNRIs (e.g., Venlafaxine, Duloxetine, Levomilnacipran)
• SSRIs (e.g., Fluoxetine, Sertraline, Paroxetine, Citalopram, Escitalopram)
• Atypical Antidepressants (e.g., Bupropion, Mirtazapine, Trazodone, Vortioxetine, Vilazodone)
• Tricyclic Antidepressants (TCAs) (e.g., Amitriptyline, Nortriptyline)
• MAOIs (e.g., Phenelzine, Tranylcypromine, Selegiline) - generally reserved for refractory cases due to significant drug and food interactions
• Psychotherapy (e.g., Cognitive Behavioral Therapy - CBT, Interpersonal Therapy - IPT)
• Electroconvulsive Therapy (ECT) for severe or refractory depression

If your symptoms or health issues persist or worsen, it is essential to contact your doctor promptly. To ensure safe use, never share your medication with others or take someone else's medication. This medication is accompanied by a Medication Guide, which provides crucial information for patients. Please read this guide carefully and review it again whenever you receive a refill of this medication. If you have any questions or concerns about this medication, consult your doctor, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek emergency medical attention. When reporting the incident, be prepared to provide details about the medication taken, the amount, and the time it occurred.