Desvenlafaxine

Desvenlafaxine is an antidepressant medication, classified as an SNRI, typically used to treat depression. Take this medication exactly as prescribed and inform your doctor of any other medications you use (prescribed or over the counter) before starting desvenlafaxine treatment, as adverse effects can occur.

Desvenlafaxine brand names

• Pristiq
• Khedezla

What is desvenlafaxine prescribed for?

Desvenlafaxine is approved by the US Food & Drug Administration for use in the treatment of major depressive disorder (MDD) ^[1].

Desvenlafaxine can be prescribed for off-label uses if it is deemed appropriate and necessary by a medical professional, including ^[2][3]:

• Anxiety symptoms
• Menopausal hot flushes

How does desvenlafaxine work?

Desvenlafaxine is a selective serotonin and norepinephrine reuptake inhibitor (SNRI). It works by blocking receptors in the brain to prevent the reuptake of serotonin and norepinephrine, thus increasing the levels of these neurotransmitters. Desvenlafaxine also has a mild effect on dopamine levels ^[4].

Depression is known to be associated with abnormal neurotransmitter levels, particularly serotonin. By increasing serotonin and norepinephrine, desvenlafaxine creates an antidepressant effect, helping to improve mood.

How is desvenlafaxine usually taken?

Desvenlafaxine is available only as an extended-release tablet, usually taken once daily. It is available in 25mg, 50mg, and 100mg tablets. Tablets should be swallowed whole without breaking or crushing ^[5].

Typically, individuals will be prescribed a starting dose of 25-50mg per day. This can be increased to a maximum of 400mg daily if required. However, 50mg is an effective dose for many people, and higher doses can increase the risk of side effects ^[1].

It is essential to take this medication exactly as it has been prescribed. Taking too much or regularly missing doses can cause adverse effects. If a dose of desvenlafaxine is missed, skip it, and take the next dose at the specified time.

How long does desvenlafaxine stay in your system?

When starting a new medication, it can take some time before the full effects occur. After starting desvenlafaxine treatment, improvements may be noticed within the first few days or weeks, although it can take up to three months before the medication has a therapeutic effect ^[5].

If desvenlafaxine treatment is stopped, it can take several days or weeks after the last dose for the medication to leave your system entirely ^[4].

It is important not to abruptly stop taking desvenlafaxine, as this can cause withdrawal symptoms and may worsen your mental state. If it is safe to stop this medication, your doctor will likely reduce your prescription gradually to prevent withdrawal symptoms and adverse reactions ^[6].

Desvenlafaxine side effects

When starting a new medication, it is common to experience side effects. These will usually reduce within the first few weeks without the need for intervention. However, if they continue or become problematic, changing or reducing your medication may be required.

Common side effects of desvenlafaxine include ^[5][6]:

• Stomach upset, such as nausea, vomiting, diarrhea, or constipation
• Headaches
• Dry mouth
• Fatigue
• Drowsiness
• Dizziness
• Agitation
• Restlessness
• Irritability
• Blurred vision
• Shaking
• Insomnia
• Nightmares
• Increasedheart rate
• Sexual dysfunction, such as reduced libido

In some cases, serious side effects or allergic reactions can occur. You should contact your doctor immediately if you experience the following adverse effects when taking desvenlafaxine ^[1][6]:

• Swelling of the face or mouth
• Rash or hives
• Breathing difficulties
• Cognitive impairments, such as reduced memory or concentration
• Feeling very weak or unsteady
• Fainting or falling
• Rapid or irregular heartbeat
• Fever
• Confusion
• Muscle or joint pain
• Unexplained bleeding or bruising
• Seizures
• Loss of consciousness

Desvenlafaxine precautions

Suicidal ideation

Antidepressant medications are designed to reduce symptoms of depression, including suicidal thoughts. However, when starting a new antidepressant treatment, some people may notice new or worsening suicidal ideation. This risk is significantly higher in individuals under the age of 24 ^[1].

If you notice any concerning changes in your mental state or have thoughts of self-harm or suicide, contact your doctor or mental health professional immediately.

Health history

You should inform your doctor of your physical and mental health history before starting a new medication to ensure this medication is safe for you to take.

Individuals should be screened for bipolar disorder before starting desvenlafaxine treatment, as antidepressants can cause the onset of a manic episode in those with bipolar ^[5].

Additionally, inform your doctor if you have a history of heart, liver, or kidney disease, lung or breathing conditions, glaucoma, seizures, or elevated blood pressure, as this medication may be unsafe for you or could cause adverse effects. Alternatively, your doctor may prescribe you a reduced dose and ensure careful physical health monitoring during your treatment ^[6].

Serotonin syndrome

Medications that increase serotonin levels, such as desvenlafaxine and other antidepressants, can cause serotonin syndrome. This can occur when these medications are taken alone, although the risk increases if the medications are combined. As such, it is advised not to take multiple antidepressant treatments to prevent this risk ^[5].

Monoamine oxidase inhibitors (MAOIs), a type of antidepressant, can cause a particularly high risk of serotonin syndrome. It is advised to wait two weeks between doses if switching from desvenlafaxine to an MAOI or vice versa ^[1].

If serotonin syndrome occurs, desvenlafaxine treatment should be stopped and the appropriate treatment administered. Symptoms of serotonin syndrome can include ^[2]:

• High temperature
• Nausea and vomiting
• Rapid or irregular heartbeat
• Hallucinations
• Muscle stiffness
• Change in mental state

Pregnancy and breastfeeding

Tell your doctor if you are pregnant or planning to become pregnant before starting desvenlafaxine. There may be some risk of harm to the fetus, particularly in the third trimester, if desvenlafaxine is used during pregnancy. It is important to fully understand the potential risks of this medication and untreated depression to make an informed decision about your treatment ^[1].

Inform your doctor if you are breastfeeding, as desvenlafaxine can be excreted in breast milk and passed onto breastfeeding infants in small amounts. If the benefits of medication outweigh the risks, it may be necessary to continue treatment and closely monitor your baby for unusual changes in their physical and mental state ^[2].

Bleeding

SNRIs, such as desvenlafaxine, can increase the risk of abnormal bleeding, especially if used alongside NSAIDs, Aspirin, or other blood-thinning medications ^[1].

Discontinuation syndrome

If desvenlafaxine has been used for a prolonged period and stopped, it can cause withdrawal symptoms, also known as discontinuation syndrome. This risk is higher if the medication is stopped suddenly. As such, doctors will gradually reduce your prescription when stopping this medication to prevent these effects.

Withdrawal symptoms of desvenlafaxine can include ^[7]:

• Agitation
• Irritability
• Depressed mood
• Anxiety
• Dizziness
• Ringing in the ears
• Headaches
• Unusual sensations in the brain, often referred to as brain ‘zaps’
• Fatigue
• Insomnia
• Seizures

Desvenlafaxine interactions

Desvenlafaxine can interact with other medications or substances, which may cause an increased risk of side effects or a reduction in the effectiveness of your medication. This can include other antidepressants, amphetamines, blood thinners, anticonvulsants, anxiolytics, migraine medications, sedatives, tranquilizers, opioids, St John’s wort, and tryptophan ^[6].

Always discuss your medications with your doctor before starting a new prescription.

It is also advised to avoid or limit alcohol use while taking desvenlafaxine, as this can cause physical health issues ^[1].

Desvenlafaxine storage

Always store your medication in a safe place where children cannot reach it.

Store desvenlafaxine in an airtight container and at room temperature.

If you have medication that is out of date or no longer needed, do not put it in the bin or flush it down the toilet, as this can cause unnecessary risks. Contact your local pharmacy or a medical professional for advice on safe disposal of unneeded medications.

What to do if you overdose on desvenlafaxine

In the event of a desvenlafaxine overdose, call a medical professional or Poison Control, or if in need of emergency medical attention, call 911.

Symptoms of a desvenlafaxine overdose can include ^[6]:

• Vomiting
• Fever
• Confusion
• Slow, fast, or irregular heart rate
• Muscle stiffness, pain, or tremors
• Seizures
• Loss of consciousness

Desvenlafaxine alternatives

For the treatment of major depressive disorder, several alternative medications are available, including ^[8]:

• Other SNRIs, such as duloxetine, venlafaxine, and levomilnacipran
• Selective serotonin reuptake inhibitors (SSRIs), such as citalopram, fluoxetine, and sertraline
• Tricyclic antidepressants, such as amitriptyline, doxepin, and imipramine
• Atypical antidepressants, such as bupropion and mirtazapine
• MAOIs, such as selegiline and phenelzine

Additionally, depressive symptoms can often be improved with therapy and self-care techniques, in combination with medication. If you require a new or different treatment for depression or another psychiatric disorder, discuss this with your doctor or healthcare provider. They can advise you on potential treatment options, which may vary depending on your medical history, condition, symptoms, and medication response.