Healthy Living

Pristiq vs. Effexor

Pristiq vs. Effexor

Pristiq and Effexor are medications that have similar compositions and are produced by the same manufacturing company. 

Pristiq (desvenlafaxine) is an antidepressant, which has been recently approved by the FDA. The composition of Pristiq is similar to Wyeth’s existing antidepressant. The patent protection of Effexor (venlafaxine) was lost in 2010. It is hoped that Effexor will be replaced soon by Pristiq. Like other antidepressants, Pristiq has shown the same effectiveness. The difference in the rating scale when compared to placebo was found to be of two points. Ironically, it was found that Pristiq was more effective when given at 50 mg rather than at 100 mg. 

Thanks to a large advertising company, a great deal of attention has been recently received by Pristiq. This medication is particularly prescribed for adults who have major depressive disorder (MDD) or simply known as depression. This medication works on both neurotransmitters called serotonin and norepinephrine, making it a unique drug class. For example, Prozac only works on serotonin, so Pristiq is an alternative drug with a more comprehensive approach. Let's find out the similarities and differences of Pristiq and Effexor below. 

Mechanism of Action and Pharmacodynamics

The neuronal reuptake of serotonin is inhibited by both Pristiq and Effexor. These medications are also known to inhibit the norepinephrine transporter. However, the affinity of both drugs is lower for the norepinephrine transporter when compared to the serotonin transporter (SERT), according to in vitro studies. Effexor is five times more powerful in vitro along with a higher risk of side effects. 

A Comparison of Effexor and Pristiq

Although both medications are useful in reducing the symptoms of major depressive disorder, Effexor is also FDA-approved for anxiety disorders, such as panic disorder, social anxiety disorder, and generalized anxiety disorder. 

Both drugs are composed of the same chemical compound. Effexor is broken by the body into Pristiq and some other chemicals. Thus, the two drugs seem to be so similar that their differences tend to be very minor. In other words, when Effexor is taken, it will eventually become Pristiq in the body. So the question is that why do these drugs individually exist?

Even though both drugs tend to be metabolized in the same way, it does not necessarily mean that they are completely identical. The reason is that Effexor contains other chemicals that the body absorbs, which then produce a different effect. Since Effexor possess these extra chemicals, people who take this drug may also experience more side effects compared with people who take Pristiq, which contains fewer compounds. For this reason, Pristiq may be a better alternative to people who experience the side effects of Effexor. 


Effexor enhances a person's mood and helps an individual to relax. This medication is very good for treating depression and can be used for the treatment of anxiety. However, suddenly stopping this medication may cause withdrawal symptoms. Pristiq is used to treat the same disorders as Effexor, but the latter is cheaper than the former. 


Effexor can effectively treat disorders such as anxiety, panic disorder, and depression. Compared to other antidepressants, Effexor causes more sleepiness, which may be suitable for people who have trouble sleeping. Effexor also enhances mood by acting on two brain chemicals, making it more beneficial to people with multiple conditions. Effexor is also cheaper. 

Pristiq helps in relieving the symptoms and reduces the relapse rates of depression. It has been reported that those who use this antidepressant for the first time find it more effective. 


Some of the side effects associated with Effexor include high blood pressure and low libido. Like other antidepressants, this medication also increases the risk of suicidal thoughts or behavior in people who are 24 years old and younger. Withdrawal symptoms can also be experienced when this medication is suddenly stopped. 

In clinical studies, the effects of Effexor and Pristiq are the same with no extra benefits linked to Pristiq. Sexual side effects can be caused by Pristiq such as low libido or the failure to have an orgasm or ejaculation. Pristiq is not cheap since a generic form of Pristiq is not available. Pristiq can also cause certain side effects in people who are 24 years old and younger. Pristiq's side effects include suicidal thoughts and behavior. When Pristiq is taken for the first time, it not very beneficial. You can try other medications until you find the one that works for you. 

Dosage Form

Effexor is in tablet form and Pristiq is available in the form of an extended-release tablet.


The symptoms of major depressive disorder can be treated by both Effexor and Pristiq. However, the symptoms of anxiety and panic disorders can also be treated by Effexor. Both medications in the brain balance the chemicals that are responsible for controlling mood, so they are classified as serotonin and norepinephrine reuptake inhibitor medications. 


Effexor should be taken with food. Pristiq, on the other hand, can be taken with or without meals. Both medications need to be daily taken at the same time. When taking these medications, improvement of the symptoms is not immediately noticed. 


Most people who are taking Pristiq have a lower dosage than Effexor. It has been reported that 50 mg of Pristiq and 75-150 mg of Effexor have the same level of effectiveness. The severity of the side effects is reduced when these medications are taken in a lower dosage. This gives Pristiq a greater advantage over Effexor.

However, it has been reported that the effectiveness of Pristiq does not improve when its dosage is increased above 50 mg. Higher dosages of Effexor also work better if Pristiq does not do a better job in reducing the symptoms of depression at the dosage of 50 mg. Regardless of whichever medication is being taken, all dosage concerns should be discussed with the doctor.

Side Effects

The common side effects associated with both medications are constipation, dry mouth, drowsiness, and sexual dysfunction. 

The side effects of Effexor may include:

The side effects associated with Pristiq are:


While taking Effexor, caution needs to be taken by those who have the following medical conditions:

People who have the above conditions and take other medications have an increased risk of developing complications. Individuals taking monoamine oxidase inhibitors (MAOIs) for 14 days should not take Pristiq or Effexor. 

Suicidal Thoughts

Suicidal thoughts may develop in adolescents and individuals when they take these medications. For this reason, it is very important to report any changes in behavior to the doctor while taking these medications. Any comments about suicide should also be reported to the doctor. 

Adverse Effects and Tolerability

To increase the inhibition of serotonin and noradrenaline, Effexor has a tolerability profile. It can cause certain side effects such as nausea, sexual dysfunction, tremor, and insomnia, along with sweating, hypertension, and dry mouth.

During the first weeks of therapy, there is a lower incidence of nausea, which is one advantage of the XR formulation. Another advantage is the one-time daily dose. Effexor is one of the antidepressants that are most commonly related to discontinuation syndrome. When taking Effexor, one side effect that should be kept in mind is hypertension or high blood pressure. There is an increased risk of hypertension when the dose is higher. 

Although both medications are effective in treating the symptoms of depression, both medications should not be taken together. Serious medical complications may arise if both medications are simultaneously taken. 

Which drug is better?

The main active metabolite of Effexor is delivered by Pristiq and without having to pass through the liver, the active state is delivered. The cytochrome P450 enzyme does not metabolize Pristiq. Effexor works oppositely to Pristiq. It passes through the liver and the hepatic cytochrome P450 enzyme and extensively metabolizes it, so it gets converted to desvenlafaxine.

As a result, drug interactions of Pristiq is lower compared to Effexor. The relative degree of serotonin and norepinephrin reuptake inhibition of Pristiq and Effexor is different. The affinity for serotonin receptors in Pristiq is less than that of Effexor. Pristiq also has a lesser affinity for norephinephrine.

Basically, the steps of metabolism through the enzyme systems in the liver are skipped when one uses Pristiq rather than using Effexor. There is no scientific evidence comparing the effectiveness, tolerance, and safety of Pristiq than that of Effexor. It is theoretically found that Pristiq is more beneficial in people with poor functioning of the enzyme CYP2D6.


Generally, the difference between Pristiq and Effexor are so slight that choosing one over the other antidepressant may not have a significant difference at all. When you opt for a cheaper medication, you might want to initially take Effexor. However, if you experience unwanted side effects, then choosing an alternative such as Pristiq may be the answer.