Can You Take Phentermine With Zoloft?

Answer

Thanks for reaching out! This is a fantastic question and one I am more than happy to go over with you.

First and foremost, there is considered to be a moderate interaction between phentermine and Zoloft (sertraline) based on how these drugs work, but the combination of an antidepressant (such as Zoloft) and phentermine has been used safely and effectively in many individuals.

You are correct that many individuals are put on both an antidepressant and anti-obesity drug, like phentermine, as the combination can sometimes yield greater weight loss results than phentermine alone. In addition, the combination of phentermine and an antidepressant is not uncommon as many obese individuals also suffer from concurrent depression and are taking anti-depressant medication for treatment.

Overall, safe and efficacious use of Zoloft and phentermine is dependent on the individual taking the medications, whether or not they have been "stabilized" on antidepressant therapy and whether or not they are being closely monitored by their doctor.

Taking Phentermine With Zoloft - Interaction

Zoloft (sertraline) is classified as an SSRI (selective serotonin reuptake inhibitor) and works by increasing the amount of the neurotransmitter serotonin in the brain. It is most commonly used to treat depression but is also beneficial for anxiety disorders and certain bipolar disorders.

Adipex-P (phentermine) is a weight loss medication that is chemically and mechanistically related to the amphetamines such as Adderall. Theoretically, it is thought that phentermine may increase levels of the neurotransmitter serotonin in the brain, increasing the risk in individuals of serotonin syndrome. Serotonin syndrome is a rare but serious disorder that is characterized by the following symptoms:

• Hyperthermia
• Muscle rigidity
• Headache
• Agitation
• Increased heart rate
• Confusion

As a general rule, the risk of serotonin syndrome is thought to be increased in those taking multiple serotonin augmenting medications. There have been rare case reports of serotonin syndrome occurring in those combining amphetamines and serotonergic drugs like Zoloft. However, these case reports aren't conclusive and there could be other contributing factors.

Studies Show Little Risk Of Serotonin Syndrome

Most of the current data suggest however that phentermine's overall effect on serotonin is minimal at doses used for weight loss and that phentermine does not increase serotonin levels in the brain when it is combined with serotonin augmenting antidepressants. 

In fact, most studies that have specifically evaluated phentermine with SSRIs have found no cases of serotonin syndrome.

Additionally, in clinical trials for the new, phentermine-containing anti-obesity drug Qsymia (phentermine/topiramate), there were many individuals who started therapy on the medication and were also taking a serotonergic antidepressant such as Zoloft. Therapy was initiated as long as the antidepressant dose had been stable for at least 3 months prior to the initiation of phentermine.

The clinical trial results showed that the combination was generally well tolerated and there was no increased risk of serotonin syndrome.

The Combination Is Often Used Together But Take Precautions

As every individual's situation and medical history are unique, it is important to speak with your doctor regarding the use of Zoloft and phentermine. As mentioned above, however, the combination is generally considered safe provided the following:

• You are closely monitored by the doctor for adverse events such as elevated blood pressure and other excess serotonin-related effects

• You have been stabilized on antidepressant therapy and have been taking a consistent dose for at least 3 months

• You regularly follow up with your doctor regarding your therapy

Final Words

Thanks again for reaching out to us! I hope this answer helped.