Difference Between Paxil and Zoloft


Main Difference

The main difference between Paxil and Zoloft is that Paxil is a selective serotonin reuptake inhibitor having paroxetine hydrochloride as active moiety and Zoloft is a selective serotonin reuptake inhibitor having Sertraline hydrochloride as an active moiety.

Paxil vs. Zoloft

Paxil is the brand name of paroxetine hydrochloride; on the other hand, Zoloft is the brand name of sertraline hydrochloride. Paxil chemical structure is different from other SSRIs by having a piperidine ring while Zoloft has a chemical structure related to other selective serotonin reuptake inhibitor. Paxil is available as 10mg, 20mg, 30mg and 40mg tablets while Zoloft is available as 25mg , 50mg and 100mg tablets. Paxil oral suspension is available as 10mg/5ml; on the other hand, Zoloft concentrate is available as 20mg/ml.


Comparison Chart

Paxil is the brand of paroxetine hydrochloride used to treat major depressive disorders, panic attack, and social anxieties.Zoloft is the brand of Sertraline hydrochloride used to treat depression, panic attack, and social phobias.
Class of Drugs
Paxil is a potent and selective serotonin reuptake inhibitor.Zoloft is a selective serotonin reuptake inhibitor.
Mechanism of Action
Paxil causes inhibition of serotonin reuptake and GRK2Zoloft causes inhibition of CNS neuronal uptake of serotonin (5HT)
Side Effects Management
Side effects of Paxil more than those of Zoloft.Side effects of Zoloft become worse with time.
Use in Pregnancy
Paxil use in pregnancy is not recommended as it is associated with shorter duration of pregnancy.Zoloft causes poor neonatal adaptation syndrome when used in late pregnancy
Therapeutic Uses
Depression, Post-traumatic stress disorder, Premenstrual syndrome, Hot flashesDepression, Post-traumatic stress disorder, Premenstrual syndrome, Social anxiety disorder

What is Paxil

Paxil is a selective serotonin reuptake inhibitor (SSRIs) and is the trade name of paroxetine hydrochloride. Paxil helps to restore serotonin in the brain. Paxil is well absorbed after orally. Paxil has an absolute bioavailability of 50%. Paxil is excreted (less than 2%) unchanged in urine after oral administration. Paxil elevates mood, helps to induce sleep, improves appetite and energy level. Paxil helps to restore interest in daily working. Paxil decreases fear, lowers anxiety levels, improves unwanted thoughts, and the number of severe panic attacks. Paxil lessens premenstrual symptoms, including irritability, increased appetite, and anxiety. Paxil overdosage causes vomiting, fatigue, tachycardia, and moderate seizures. Paxil Plasma, serum, or blood concentrations should be monitored to detect poisoning. Plasma Paxil concentrations are in a range of 40–400 μg/L in patients receiving daily therapeutic doses. Paxil interacts with drugs which act on the serotonin system or impair the metabolism of serotonin, so increase the risk of Serotonin Syndrome or Neuroleptic Malignant Syndrome. Paxil is not prescribed with MAOIs. Paxil interacts with cytochrome P450 enzymes


Paxil pill, extended release pill, and liquid are available.

What is Zoloft

Zoloft is a potent, selective serotonin reuptake inhibitor (SSRIs) and is the trade name of sertraline. Zoloft is a prescription drug, and one can not take it without a prescription. Zoloft inhibits the re-uptake of serotonin by neurons, So it increases the concentration of serotonin, meaning more drug availability to act for antidepressant effects. Zoloft does not cause inhibition of noradrenaline re-uptake and has little anticholinergic activity. Zoloft is a weak inhibitor of the reuptake of dopamine clinically. Zoloft is absorbed slowly when taken orally. Zoloft reaches its highest plasma concentration in 4-6 hrs. Zoloft is 98.7% protein bind. Zoloft causes diarrhea, sleep disturbances, and sexual disturbances. Zoloft is associated with psychiatric disturbances. Zoloft causes a higher rate of insomnia and agitation as compared to other members of selective serotonin reuptake inhibitors. Zoloft increases the suicidal thoughts, so, in long therapies, the patient is monitored carefully. Zoloft causes an increase in weight after six months of therapy in some patients. Zoloft overdose causes vomiting, fatigue, ataxia, tachycardia, and seizures. Zoloft moderately inhibits some metabolizing enzymes. Zoloft is not taken with mono amine oxidase inhibitors, disulfiram, and antipsychotic drugs.


Zoloft pill and liquid is available.

Key Differences

  1. Paxil is the trade name of paroxetine hydrochloride while Zoloft is the trade name of sertraline.
  2. Paxil is used to treat anxiety and depression, while Zoloft is used to treat depression and other CNS related problem.
  3. Paxil shows more side effects, while Zoloft shows fewer side effects, but they become worse with time.


The conclusion of the above discussion is that Paxil and Zoloft are trade names of selective serotonin reuptake inhibitors having different active moieties with their effective uses in anxiety and depression.

Janet White

Janet White is a writer and blogger for Difference Wiki since 2015. She has a master's degree in science and medical journalism from Boston University. Apart from work, she enjoys exercising, reading, and spending time with her friends and family. Connect with her on Twitter @Janet__White