Zoloft is a brand name of a commonly used antidepressant, sertraline. It belongs to selective serotonin reuptake inhibitor or SSRIs group of antidepressants. Its effectiveness and safety has earned for it a lot of popularity in treatment of depressive illnesses, obsessive compulsive disorders, premenstrual dysphoric disorders and post-traumatic stress disorders.
Sertraline was discovered in 1991, since that time it is being use frequently. As compared to other anti-depressant like tricyclic antidepressant and mono amine oxidase inhibitors, zoloft is safer with lesser side effects.
How Zoloft works/ mechanism of action
Zoloft is a selective serotonin reuptake inhibitor in the brain, when sertraline is taken for some weeks; serotonin reuptake and its metabolism in the brain is inhibited resulting in increased concentration of serotonin in specific areas of brain which are involved in mood regulation and other behavioral control. Serotonin is a neurotransmitter in the brain which stimulates the brain, when its concentration in is increased, it elevates mood and alleviate the symptoms of depression.
Sertraline is also dompamine reuptake inhibitor, 5% of its antidepressive activity comes through this mechanism. Some antidepressant effect of sertraline is achieved through antagonizing alpha 1 receptors. Interesting to note, sertraline also have anti-bacterial and anti-fungal activity though minimum, that’s why it is not used for this purpose.
Indications of Zoloft
Zoloft is beneficial in a number of psychiatric illnesses, some of the conditions in which Zoloft has proven efficacy are:
1. Major depression: efficacy of setraline is comparable to TCAs and MAOIs in major depression. The additional benefit of fewer side effects makes sertraline superior to other anti-depressants:
- Depression in elderly: sertraline is approved for treatment of depression even at the age of 70 years due to little cardiac effects as compared to TCAs
- Panic disorders: clinical efficacy of sertraline is established in panic disorders in both children and adults, it reduces the frequency of panic attacks over weeks of its use
Social phobia: clinical trials support the use of sertraline in social phobia - Premenstrual dysphoric disorder: in this special situation sertraline is not taken regularly rather it is taken intermittently.
- Post-traumatic stress disorder (PTSD)
- Obsessive compulsive disorders
- Eating disorder for example binge eating disorder or bulimia nervosa
- Generalized anxiety disorders (GAD)
Side effects of Zoloft
Although side effect profile of Zoloft is favorable as compared to old antidepressant such as tricyclic antidepressants (TCA) or monoamine oxidaze inhibitors (MAOIs), yet some drug effects when appear in a patient taking Zoloft, are dangerous and he or she must consult the treating physician.
- allergic reaction ranging from skin rash and hives to sever drug reaction characterized by swelling of face, tongue, lips, or throat along with difficulty in breathing. If these effects appear, emergency service should be consulted
- Any new symptoms or worsening symptoms of mood and behavior
- anxiety
- insomnia( loss of sleep)
- panic attacks
- aggression
- restlessness
- mental or physical hyperactivity
- increased depressive thought or suicidal tendency
- muscle stiffness
- high grade fever
- fast heart rate or feeling of missing of heartbeats
- tremors
- exaggerated tendon reflexes
- loss of appetite
- nausea
- vomiting
- diarrhea
- loss of co-ordination or feeling unsteadiness
- headache
- poor concentration
- poor memory
- generalized weakness
- dizziness or fainting
- confusion
- seizures
- breathing problem i.e. shallow breathing or even breathing stops
- hallucinations (seeing object in their absence, smelling fragrance in its absence, hearing voices in its absence or feeling moving of insects on body in the absence of anything)
Any of these side effects if appear in a patient taking Zoloft, warrants its discontinuation and patient should consult the treating doctor.
Some Side effects are mild and patients who take Zoloft often experience them. Some of them may settle automatically over time and patient usually needs not to stop the drug. These include
- fatigue and sleepiness or drowsiness
- constipation, mild nausea or dyspepsia
- dry mouth
- patients feels changes in appetite and weight, either he eats too much or too little
- insomnia or loss of sleep
- reduced sexual drive, impotence and difficulty in achieving orgasm
Sertraline and serotonin syndrome
When sertraline is co-admininistered with other medication which also has serotonergic activity, this can result in life-threatening condition called serotonin syndrome. The drugs which can result in this condition are many, particularly mono amine oxidase inhibitors should be avoided while taking sertraline.
Interaction of Zoloft with other drugs
Sertraline is an inhibitor of enzyme, CYP2D6 and CYP2B6; it can affect the metabolism of drugs that are metabolized through this pathway. Toxicity of follwing drugs may be increased if co-administered with sertraline, metoprolol, desipramine, imapramine, nortriptyline, dextromethorphane and haloperidol.
Sertraline decreases the metabolism of amphetamine, thus it enhances the stimulatory effects of amphetamine when taken together.
Sertraline slightly inhibit the metabolism of tolbutamide, diazepam and warfarin, so if these drugs are to be taken with sertraline, their dose must be reduced to avoid their side effects.
Zolpidem and phenytoin enhance metabolism of sertraline so it is cleared from the body earlier which reduce its efficacy.
Zoloft withdrawal symptoms or Zoloft discontinuation syndromeIf sertraline is discontinued abruptly it can result in a number of symptoms known as Zoloft discontinuation syndrome. Most common withdrawal symptoms that patient experience after abrupt stoppage of Zoloft, are listed below
- agitation
- irritability
- dizziness
- headache
- nervousness
- crying
- emotional liability
- anger
- bad dreams
- worsening of mood
- insomnia or loss of sleep
Zoloft withdrawal effects can be avoided if it is gradually tapered and stopped over at least three weeks.
In conclusion, Zoloft is an antidepressant which has proven efficacy in many psychiatric illnesses particularly depression. It is safer than other antidepressants. When it is started, proper instructions should be given to the patient regarding its side effects. In order to avoid drug interactions, a review of drugs that patient is already taking is done and if needed dose adjustments or omission of some drug is done. Zoloft should not be stopped abruptly in order to avoid untoward effects of its withdrawal.