Zoloft was approved in 1991 by the Food and Drug Administration.  It had been previously used in the United Kingdom.  It is manufactured by the largest pharmaceutical company in the world, Pfizer and has made $billions for the company.

Zoloft (sertraline) was the second of a “new” type of anti-depressants known as serotonin-specific reuptake inhibitors (SSRIs) which are used to treat major depression and a number of other mental disorders.  By 2005, the medication was the number-one antidepressant on the US market and had nearly 30 million prescriptions issued each year.  In its peak year, Zoloft had revenues of nearly $2.6 billion worldwide.

The SSRIs were designed to have fewer side effects than older anti-depressants as they affect only the serotonin receptor.  Serotonin is a neurotransmitter (chemical messenger) that affects the mood state, along with sleep and other functions.  The first SSRI on the US market was Prozac, which has seen a number of legal and medical issues.

Zoloft, like other SSRIs including Prozac and Paxil, may cause a number of side effects.  Some of these side effects are mild or irritating, while others may be severe and life threatening.

In 2004, the FDA determined that there was an increased risk of suicide in children and adolescents taking SSRI anti-depressants.  The following year, the FDA began requiring a black box warning regarding the increased risk of suicide for all SSRI type antidepressants, including Zoloft.

In 2006, the FDA began requiring additional warnings regarding the risk of birth defects in pregnant women who took SSRIs.  A study published in the New England Journal of Medicine found that women who took SSRIs during the second half of a pregnancy were six times more likely to have a baby with persistent pulmonary hypertension.

Zoloft has also been shown to increase the risk of birth defects when taken by women who are pregnant.  Pfizer has multiple lawsuits filed against it regarding birth defects.  So many lawsuits are pending that they have been consolidated into multidistrict legislation (MDL) to speed litigation.

What is Zoloft

Zoloft is the brand name for the generic medication sertraline and is one member of the serotonin-specific reuptake inhibitor (SSRI) class of anti-depressants.  It is approved to treat mental disorders such as major depressive disorder, obsessive-compulsive disorder, panic disorder, premenstrual dysphoric disorder (PMDD), posttraumatic stress disorder (PTSD) and social anxiety disorder.  The only indication that was approved for use in children was obsessive compulsive disorder.

It is also used as off-label treatment for bipolar disorder, body dysmorphic disorder, premature ejaculation, and headaches.  Physicians are allowed to prescribe medication for off-label indications but the manufacturer cannot promote the use of the medication for reasons that are not approved by the FDA.

The SSRIs work by targeting the serotonin receptors in mood centers of the brain.  Serotonin is a neurotransmitter (chemical messenger) in the brain that helps increase mood levels and affects the sleep cycle.  SSRIs block “reuptake” of serotonin that has been released so that it can send more “feel good” messages to the rest of the cells in the mood centers.

It is available in tablets of 25 mg, 50 mg and 100 mg.  It is also available in liquid to be taken by mouth.  In most anti-depressants, full effect does not begin to occur for two to three weeks after the medication is started.

Side Effects and Drug Interactions of Zoloft

Zoloft has a number of side effects, similar to other SSRIs.  Most of these side effects are related to its targeting of serotonin.  It may also interact with other medications.  In most cases, side effects are minor but some adverse effects may be severe or even life-threatening.

The most common side effects of Zoloft include:

  • Nausea
  • Dry mouth
  • Changes in weight
  • Dizziness
  • Insomnia
  • Drowsiness
  • Anxiety
  • Irritability
  • Headache
  • Diarrhea
  • Sexual dysfunction in both males and females

Zoloft can also have drug interactions with other medications including:

  • Pain medications, antianxiety agents and muscle relaxants (increased sedation)
  • Dextromethorphan (headaches, pain, increased heart rate)
  • Diuretics such as furosemide and hydrochlorothiazide (decreased sodium levels)
  • Antihistamines such as diphenhydramine or chlorpheniramine (increased sedation)
  • Other antidepressants (increased side effects)
  • Appetite suppressants such as phentermine (nervousness, heartbeat irregularities and more severe effects)
  • Caffeine and ergot combinations (serotonin syndrome risk)

Serious Adverse Events of Zoloft

Serotonin Syndrome

Zoloft may cause side effects from a condition called “serotonin syndrome” these effects are more severe and may require emergency medical treatment.  The risk of the development of serotonin syndrome may be increased with certain medications including dextromethorphan, meperidine, ergotamine and derivatives, and herbal supplements such as St. Johns Wort and tryptophan.

Serotonin Syndrome symptoms include:

  • Increased temperature
  • Racing heart or abnormal heart beats
  • Seizures
  • Confusion
  • Loss of balance or coordination
  • Loss of consciousness
  • Hallucination

Zoloft in Pregnancy

Zoloft is now listed as a “Category C” medication and may cause complications for women who are pregnant and their fetus.  When taken by pregnant women, Zoloft may cause”

  • Miscarriage
  • Premature Birth
  • Hypoplastic Left/Right Heart Syndrome (HLHS, HRHS) and other heart defects
  • Persistent Pulmonary Hypertension in Newborn (PPHN), fatal in 10% of infants
  • Cranial defects including anencephaly, spina bifida, cleft palate or lip
  • Ophalocele (abdominal organs on the outside of the body)
  • Scoliosis, Club Feet or other malformation of bones
  • Delayed development and Autism Spectrum Disorder
  • Withdrawal symptoms in infants

Medical groups have warned that women who are or are planning on becoming pregnant should avoid taking any SSRI unless the benefits clearly outweigh the risks.

Zoloft and Suicide

In 2004, the FDA began requiring that all manufacturers of SSRI antidepressant medications have a black box warning regarding an increased risk of suicide.  A black-box warning is a notice placed at the top of all prescribing information in a “black box” to ensure that health practitioners see the warning before prescribing the medication.  A black box warning is the most severe warning regarding any medication.

Zoloft’s black-box warning includes information about the increased risk of suicidal thoughts and behavior in children, adolescents, and young adults with short-term use for major depression.  Patients who take Zoloft for depression should be monitored for signs and symptoms of suicidal behavior and other behavior.

Zoloft Lawsuits

Birth Defects

More than 250 lawsuits have been filed against Pfizer regarding birth defects that occurred after Zoloft was taken during pregnancy.  Lawyers for the plaintiffs have claimed that the company did not adequately warn practitioners and patients about the risks of taking Zoloft during pregnancy.  Lawsuits filed in federal court have been consolidated into multidistrict litigation (MDL) in the US District Court for the Eastern District of Pennsylvania.  The MDL will be adjudicated by Judge Cynthia M. Rufe.

Claims of injury include birth defects including

  • Respiratory distress syndrome
  • Heart defects
  • Anencephaly
  • Cleft palate and lip
  • PPHN (Persistent Pulmonary Hypertension of the Newborn)
  • Other birth defects


In January of 2013, a class action lawsuit was filed against Pfizer claiming that the company deliberately and falsely misled consumers about the effectiveness of Zoloft.  This lawsuit is based on the company’s advertising campaigns and states that Pfizer has withheld information regarding effectiveness from both physicians and consumers including accusations regarding payments made to physicians, ghost written articles claiming effectiveness, manipulation of clinical data and hiding of the results negative studies.  The class action suit was filed in the US District Court for the Northern District of California, San Jose Division.  The suit was filed on behalf of one named plaintiff and consumers nationwide.

View Sources
  1. Butler, J., Leonard B. E. (October 1998). The Platelet Serotonergic System in Depression and Following Sertraline Treatment. International Clinical Psychopharmacology. Accessed on 25 June 2014. http://journals.lww.com/intclinpsychopharm/Abstract/1988/10000/The_Platelet_Serotonergic_System_in_Depression_and.5.aspx
  2. Chambers, C.D., et al. (9 February 2006) Selective Serotonin-Reuptake Inhibitors and Risk of Persistent Pulmonary Hypertension of the Newborn. New England Journal of Medicine. Accessed on 25 June 2014. http://www.nejm.org/doi/full/10.1056/NEJMoa052744
  3. Flament, MF, Lane RM, Ying, Z. (September 1999). Predictors of an Acute Antidepressant Response to Fluoxetine and Sertraline. International Clinical Psychopharmacology. Accessed on 25 June 2014. http://www.ncbi.nlm.nih.gov/pubmed/10529069
  4. Food and Drug Administration. (30 June 2006). FDA Approves First Generic Sertraline. Accessed on 25 June 2014. http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/2006/ucm108684.htm
  5. Harris, Gardiner. (2 September 2009). Pfizer Pays $2.3 Billion to Settle Marketing Case. The New York Times. Accessed on 25 June 2014. http://www.nytimes.com/2009/09/03/business/03health.html?_r=2
  6. Hostetter, A., Ritchie, J.C., Stowe, Z.N. (7 June 2007). Amniotic Fluid and Umbilical Cord Blood Concentrations of Antidepressants in Three Women. Biological Psychiatry. Accessed on 25 June 2014. http://www.biologicalpsychiatryjournal.com/article/S0006-3223%2800%2900958-6/abstract
  7. Judicial Panel on Multidistrict Litigation. (January 2012) Case 2342. Accessed on 25 June 2014. http://www.jpml.uscourts.gov/sites/jpml/files/MDL-2342-Tag-Along-Transfer-12-13.pdf
  8. Louik, C., et al. (28 June 2007). First-Trimester Use of Selective Serotonin-Reuptake Inhibitors and the Risk of Birth Defects. New England Journal of Medicine. Accessed on 25 June 2014. http://www.nejm.org/doi/full/10.1056/NEJMoa067407
  9. Johnson, L. . (31 Jan 2013). Pfizer disputes claim against antidepressant. USA Today. Accessed on 25 June 2014. http://www.usatoday.com/story/news/nation/2013/01/31/pfizer-zoloft-lawsuit/1881441
  10. Mayo Clinic (2014) Antidepressants: Safe during pregnancy?. Mayoclinic.org. Accessed on 25 June 2014. http://www.mayoclinic.org/healthy-living/pregnancy-week-by-week/in-depth/antidepressants/art-20046420
  11. Mayo Clinic. (2014) Serotonin Syndrome. Mayoclinic.org. Accessed 25 June 2014. http://www.mayoclinic.org/diseases-conditions/serotonin-syndrome/basics/definition/con-20028946
  12. Moylan, T.(17 April 2013). Zoloft Birth Defects MDL Created, Assigned To Eastern District Of Pennsylvania. LexisNexis Communities. Accessed on 25 June 2014. http://www.lexisnexis.com/community/litigationresourcecenter/blogs/litigationblog/archive/2012/04/17/zoloft-birth-defects-mdl-created-assigned-to-eastern-district-of-pennsylvania.asp&xgt;.
  13. NAMI (May 2007). Zoloft Fact Sheet. College of Psychiatric and Neurological Pharmacists. Accessed on 25 June 2014. http://www.namihelps.org/assets/PDFs/fact-sheets/Medications/Zoloft.pdf
  14. NAMI (2014) Depression. Accessed 25 June 2014. National Institute of Mental Health. http://www.nimh.nih.gov/health/topics/depression/index.shtml
  15. NAMI (2014) Panic Disorder. Accessed 25 June 2014. National Institute of Mental Health. http://www.nimh.nih.gov/health/topics/panic-disorder/index.shtml
  16. Nordqvist, C. (1 February 2013). Zoloft No Better Than Dummy Pill, Says Lawsuit. Medical News Today. Accessed on 25 June 2014. http://www.medicalnewstoday.com/articles/255782.php
  17. Pfizer. Zoloft Medication Guide. Accessed on 25 June 2014. http://labeling.pfizer.com/ShowLabeling.aspx?id=517
  18. Quallich, George J. (18 March 2005). Development of the Commercial Process for Zoloft/sertraline. Chirality. Accessed on 25 June 2014. http://onlinelibrary.wiley.com/doi/10.1002/chir.20113/abstract
  19. RxList. Zoloft Drug Information. Accessed on 25 June 2014. http://www.nejm.org/doi/full/10.1056/NEJMoa052744
  20. Wagner, K.D., et al. (27 August 2003). Efficacy of Sertraline in the Treatment of Children and Adolescents with Major Depressive Disorder.. Journal of the American Medical Association. Accessed on 25 June 2014. http://jama.jamanetwork.com/article.aspx?articleid=197174
  21. Weller, I.V.(December 2004) Report of the CSM Expert Working Group on the Safety of Selective Serotonin Reuptake Inhibitor Antidepressants. Accessed on 25 June 2014. http://www.mhra.gov.uk/home/groups/pl-p/documents/drugsafetymessage/con019472.pdf