Zoloft 50 mg

Zoloft 50 mg - Anxiety | Social phobia

This article was medically reviewed by M.Pharm, Marko Tanaskovic on August 12, 2018. To read more about an author, click here.

Zoloft 50 mg is a drug that is produced by the American pharmaceutical company named Pfizer and contains sertraline. It belongs to the group of medicines called selective serotonin reuptake inhibitors (SSRIs). It has almost no effect on noradrenaline and dopamine reuptake. Increasing the concentration of serotonin in the blood causes changes in mood, and Zoloft 50 mg is used to treat the following conditions:

  • Anxiety
  • Social phobia
  • Post-traumatic disorders
  • Major depression
  • Obsessive-compulsive disorders


As with all other drugs that increase levels of serotonin in the blood, Zoloft 50 mg may also cause serotonin syndrome, particularly when taken concomitantly with other serotonergic drugs or drugs that increase serotonin levels (e.g. MAO inhibitors). Serotonin syndrome is a serious condition that can endanger the patient's life, so it is essential for patient to contact physician immediately if any of the following signs occur:

  • Anxiety
  • Loss of muscle coordination
  • Severe headache
  • Fever
  • Seizures
  • Heart rhythm disorders

For this reason, concomitant use of Zoloft 50 mg, with monoamine oxidase (MAO) inhibitors, such as:

  1. moclobemide
  2. isocarboxazid (used to treat depression)
  3. selegiline (used for the treatment of Parkinson's disease)
  4. linezolid (an antibiotic) is contraindicated

If it is necessary to introduce Zoloft 50 mg after discontinuation of MAO inhibitors it is necessary to wait at least two weeks before starting the treatment with Zoloft 50 mg.

FDA reported a clinically significant interaction with drug named pimozide (a drug used to treat depression), wherein Zoloft 50 mg caused an increase in the concentration of pimozide for about 40%, which can cause serious adverse effects (e.g. heart failure).1

Zoloft 50 mg should be cautiously used in the following conditions:

  • In patients suffering from epilepsy. There have been reports of convulsions induced by this drug, so patients who already suffer from epilepsy are at increased risk of seizures.
  • In patients with hyponatremia or in patients taking medications that can reduce sodium levels in the blood (e.g. diuretics). Zoloft 50 mg has an impact on antidiuretic hormone secretion which directly reduce sodium levels in the blood. Given that sodium has many important roles in the body, and tis deficiency causes severe disorders including convulsions and coma.
  • In patients with liver damage. Zoloft 50 mg can cause an increase in the levels of liver enzymes in the blood and acute liver injury2 and therefore, must be cautiously used in patients who already have liver problems.
  • In diabetics. Patients with diabetes should keep in mind that this drug can affect blood sugar levels, and frequent monitoring of glucose levels is recommended during the treatment.

Abrupt discontinuation of Zoloft 50 mg therapy can lead to the withdrawal symptoms, such as:

  • Anxiety
  • Feeling of numbness or tingling in the hands and feet
  • Headache
  • Tremor
  • Dizziness

Therefore, it is necessary to discontinue Zoloft 50 mg treatment slowly by gradually reducing the dose.

It can be administered in children aged 6-17 years who suffer from obsessive-compulsive disorder.

This drug does not cause physical or psychological addiction.

Zoloft 50 mg, pregnancy and lactation

Use of this drug in the last trimester of pregnancy increases the risk of cyanosis, respiratory depression, somnolence, and hypoglycaemia in newborns, and therefore its use during pregnancy (especially in the last trimester) is not recommended.

Infants whose mothers had taken Zoloft 50 mg during pregnancy have a higher incidence of persistent pulmonary hypertension.

To date, no reported side effects in infants whose mothers took the drug during breastfeeding, but caution should certainly be exercised when this drug is taken during breastfeeding.

How to use

The usual initial dose is one tablet (50 mg) a day, in the morning or in the evening, regardless of the meal.

If there is no symptoms improvement after one month of therapy, the dose may be increased up to 100 mg once a day.

Sometimes, the physician may decide to start with lower-dose therapy (25 mg once a day) and to increase it up to 50 mg after one week of treatment.


Zoloft 50 mg should not be used in combination with the following drugs:

  • MAO inhibitors
  • Pimozide
  • Drugs used to treat severe pain (e.g. tramadol, morphine and oxycodone)
  • Triptans (medicines used to treat migraine), such as: zolmitriptan and sumatriptan.
  • Antiepileptics (e.g. phenytoin)
  • Oral anticoagulants (warfarin)
  • Benzodiazepines (e.g. diazepam)
  • Derivatives of sulfonylureas (medicines used for to treat diabetes)
  • Diuretics
  • Lithium (drug used for the treatment of psychoses)
  • Antiarrhythmics
  • Tricyclic antidepressants

Side effects

The most common side effects of Zoloft 50 mg are nausea and sexual dysfunction (in men).

It can also cause following side effects:

  • Hyperthermia
  • Headache
  • Dizziness
  • Seizures
  • Coma
  • Hypertension
  • Insomnia
  • Anxiety
  • Paraesthesia
  • Palpitations
  • Impotence
  • Nervousness
  • Lymphadenopathy
  • Hyponatremia
  • Increased secretion of prolactin
  • Glaucoma
  • Alopecia
  • Inflammation of the joints
  • Difficulty urinating
  • Hemorrhoids
  • Akathisia
  • Hernia
  • Leukopenia
  • Pancreatitis
  • Jaundice
  • Allergy


  1. FDA PDF
  2. Sertraline

Information on this website are provided for educational purposes only and are not intended for medical advice, diagnosis or treatment.

If you have any concerns or questions about your health, you should always consult with a physician or other health-care professional.

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