What Is Paxil Used For? Paroxetine Uses And MOA

Last Updated: December 18, 2019

Authored by Roger Weiss, MD

Paxil for anxiety and depression works by increasing serotonin in the brain, a chemical responsible for stabilizing mood. Paxil for depression has good tolerability and low addictive quality.

Paxil Mechanism Of Action

Paxil or Paroxetine brand name helps in restoring the balance of serotonin in the brain and other neurotransmitters that nerves use to communicate. In more detail, Paxil prevents the reuptake of serotonin, which means there will be more of this neurotransmitter to attach to receptors in the brain.
The reuptake process removes the released neurotransmitters, terminating their actions on adjacent nerves. This way, the quantity of free serotonin will be increased, creating new connections between nerve cells.

Paroxetine Uses

What is paroxetine? Paxil is an SSRI aimed at improving appetite, sleep, mood, and energy level. It can also restore the patient’s interest in daily living, decrease anxiety, fear, panic attacks, and keep away unwanted thoughts. The drug can also reduce the involuntary need to do repetitive tasks such as counting, hand-washing, or checking, which can affect the quality of daily living.

Paxil for depression

The primary purpose of Paroxetine is to help people with depression. The efficacy of this drug use is similar to other antidepressants. For example, the comparison Lexapro vs. Paxil will show that both help people deal with depression, but Paxil has lower toxicity and fewer side effects.

A study where 120 patients were given Paxil and 60 placebos for eight weeks showed that those who took the drug showed noticeable improvement in their depression symptoms. They also became calmer, more even-tempered, eager to try new experiences and less self-conscious.

Paxil for generalized anxiety disorder (GAD)

Paroxetine has shown to be effective in doses varying from 20 mg to 50 mg in a single daily dose for patients suffering from GAD. The use of Paroxetine for anxiety showed positive effects after eight weeks of treatment.

Paxil is the second depression medication that was approved by the FDA for the treatment of generalized anxiety disorder. Compared to benzodiazepines, the primary treatment for GAD for many years, Paroxetine has proved to be more efficient in reducing the psychic symptoms, such as tension, worry, concentration difficulties, and irritability. It also has fewer side effects, and it is more tolerable.

Paxil for the premenstrual dysphoric disorder (PMDD)

Scientists demonstrated in this study that Paroxetine, in daily doses varying from 12.5 mg to 25 mg, has proved efficient in treating the main symptoms of PMDD, such as depressed mood, irritability, affective lability, difficulty concentrating and tension, but also physical symptoms, including headaches, weight gain, bloating, muscle and joint pain, breast swelling or tenderness. The research participants also showed an improvement in social functioning.

woman with premenstrual disorder

Paxil for hot flashes associated with menopause

Seroxat is the first nonhormonal option for women suffering from hot flashes related to menopause, who do not want to take hormonal medication. Night sweats and hot flashes are also known as vasomotor symptoms (VMS).

A study on Paroxetine and vasomotor symptoms showed that drug usage led to a reduction of 33% to 67% in the frequency of hot flashes in a treatment period of 6 to 12 weeks. Patients using Paroxetine for hot flashes also reported a reduction in the severity of VMS symptoms. The participants in the study experienced mild-to-moderate side effects, and the tolerability was improved by lowering the dose to between 7.5 and 12.5 mg per day.

Paxil for obsessive-compulsive disorder (OCD)

When using Paxil for OCD, the dose has to be higher compared to the one used for depression. It also takes longer for the drug to improve OCD symptoms. For example, if patients with depression show improvement after 2-6 weeks of treatment, for those with the obsessive-compulsive disorder, the medication will start working after 10-12 weeks.

Patients using Seroxat for OCD said they had seen a drop in common compulsive behaviors such as excessive double-checking, hoarding, extreme cleaning and washing, tapping, counting, and over-arranging objects. It also made them calmer, happier, and helped them keep under control the feeling of fear.

Paxil for panic disorder

Paroxetine can be successfully used for panic disorder. Participants showed significant improvement after the first four to 12 weeks. Using Paxil for panic attacks is as effective as other treatments such as TCADs, CBT, or benzodiazepines, but it is better tolerated and has minimum side effects. The most effective dose for panic disorder has proven to be 40 mg a day.

Paxil for posttraumatic stress disorder (PTSD)

Paroxetine is one of the two drugs approved by the FDA for the treatment of PTSD. Patients received treatment with Paxil for six months. The results showed an improvement in symptoms from 100% to 64% with a daily dose of 20 mg. Paxil for PTSD proved efficient, and the reported side effects were only mild.

Paxil for social phobia (social anxiety disorder)

The primary purpose of this drug is to change the functioning of neurotransmitters in the brain, such as serotonin. This change also results in a significant reduction in social phobia symptoms. Studies have shown that using Paxil for social anxiety helped 50% to 80% of the participants see an improvement in their symptoms after 8 to 12 weeks of treatment.

The patients reported an improvement in their anxiety, fear, and avoidance, and the patients who achieved clinical remission with Paroxetine were three times more compared to those treated with placebo.

young woman with social phobia

Paxil for premature ejaculation

A known Paxil sexual side effect is delayed ejaculation. Some physicians use this effect to the patient’s advantage, especially those with premature ejaculation. Regarding the Paxil erectile dysfunction efficiency, there are two studies worth mentioning.

In the first one, subjects were given a dose of 20 mg several hours before being engaged in sexual intercourse. After four weeks of treatment, the time from vaginal penetration to ejaculation increased to 3.4 minutes. In the second study, subjects used10 mg daily for three weeks and 20 mg for the following four weeks. After three weeks, the average time to ejaculation increased to 3.8 minutes and after four weeks to 6.0 minutes. Only seven out of the total of 42 subjects reported side effects.

How Long It Takes Paxil To Work

Paxil can take several weeks to start working, depending on the condition for which it is used. Some patients can experience the effects after two weeks, but the full therapeutic effect may be achieved only after eight weeks of treatment.

During the first two weeks, there might be an improvement in appetite, energy, and sleep, an early sign that the drug starts working. More severe symptoms such as lack of interest in daily activities and depressed mood might need between six to eight weeks.

How To Use Paroxetine

The best time of day to take Paxil is in the morning, swallowing the tablet whole, during breakfast to decrease nausea. Some patients might experience sleepiness during the day. In this case, the doctor might recommend taking it in the evening.

Paxil dosage depends on the patient’s condition, age, response to treatment, and other medications that the patient takes. For example, taking Paxil and Adderall at the same time can result in serious side effects such as anxiety, racing thoughts, confusion, seizure, fever, increased heart rate, tremor, and hallucinations, to name a few.

Usually, it is prescribed a lower dose to reduce the risk of side effects. Patients are advised to continue the treatment even if the symptoms improve. Suddenly stopping the treatment might worsen the condition’s symptoms and also lead to headache, mood swings, tiredness, and sleep changes.

man with severe headache

Alcohol should be avoided while using the drug. If a dose is missed, it can be taken at a later time, but not too close to the next dose to avoid doubling the quantity of the medication.

How long does Paxil stay in the system? The drug’s half-life is between 21 and 24 hours. This means that half of the drug will be eliminated from the system in 24 hours after stopping the usage. Paroxetine will be removed from the system after five days.

How To Tell If Treatment Is Working?

Although Paxil for anxiety and depression will start working after about two months of treatment, the patient will notice the drug working after the first week. Unfortunately, the first ones to kick in might be the side effects, such as tiredness, lethargy, problems sleeping or stomach issues. This might be a sign that the doctor will have to lower your dose.

The is also a connection between Paxil and weight gain, that is why the APA does not recommend the drug as the first choice for individuals who have type 2 diabetes, are obese or suffer from constipation or urinary hesitancy.

Paxil is a habit-forming substance with a severe discontinuation syndrome. In case of any signs of dependence, contact the professionals from drug rehab centers. They will give a confidential and compassionate advice on the treatment approaches to this addiction.

Page Sources

  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2799251/
  2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1079696/
  3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4476484/
  4. https://www.ncbi.nlm.nih.gov/pubmed/16831110
  5. https://www.ncbi.nlm.nih.gov/pubmed/15853560
  6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5724881/
  7. https://www.health.harvard.edu/newsletter_article/treating-social-anxiety-disorder

Published on: May 23rd, 2019

Updated on: December 18th, 2019

About Author

Roger Weiss, MD

Dr. Roger Weiss is a practicing mental health specialist at the hospital. Dr. Weiss combines his clinical practice and medical writing career since 2009. Apart from these activities, Dr. Weiss also delivers lectures for youth, former addicts, and everyone interested in topics such as substance abuse and treatment.


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