Seroquel Mechanism of Action: How Long It Takes Quetiapine To Work

Last Updated: June 3, 2020

Seroquel is popularly known for its use in the treatment of specific mental disorders. The precise mechanism of action of Seroquel has not been confirmed by enough data and research. The available information about quetiapine mechanism of action is based on the known facts about atypical antipsychotics. On that note, let’s take an in-depth look at the proffered mechanism of action of quetiapine in relation to the general process of antipsychotics that share the ingredients of Seroquel.

Quetiapine Mechanism of Action

Seroquel is classified as an antipsychotic medicine, and the resulting calming activity from the administration of the drug is believed to be down to the combination of antagonism at specific receptors in the brain. These include the 5HT2A receptors in the frontal cortex and D2 receptors in the mesolimbic pathway. These effects become dangerously increased when one overdoses in a bid to get Seroquel high effects.
Doctor discuss Serouqel MOA with senior patient.

How Does Seroquel Work For Mental Diseases?

In the treatment of schizophrenia, it is believed that antipsychotics such as Quetiapine work to reduce all symptoms of the condition – negative and positive – through the modulation of central serotonergic and dopaminergic activity in the brain. The activity in the D2 receptors suppresses the positive symptoms of the condition while the activity in the 5HT2A receptors suppresses the negative symptoms.
Serotonin and dopamine have differing roles in the effect of Seroquel in the brain, and the introduction of quetiapine into the system directly affects the production of both. This is so because an excess of dopamine in the mesolimbic tract is believed to be a major cause of the positive symptoms of schizophrenia. Thus, the introduction of Norquetiapine – an active metabolite of Quetiapine that causes antagonism of dopamine in the D2 receptors – directly suppresses dopamine levels, consequently reducing or eliminating the positive symptoms of schizophrenia.
In the same way, excess serotonin at the 5HT2A receptors is believed to be the cause of the negative symptoms of schizophrenia. The antagonism of serotonin production at these receptors (through the administration of Quetiapine) directly suppresses those negative symptoms.

How Long Does It Take For Seroquel To Work?

The period it takes for Seroquel to kick in depends on the variant of the medication that is administered, and it may also vary according to the condition suffered by the user. The tablet is available in immediate-release (Seroquel IR) and extended-release (Seroquel XR) states, and both variants require different amounts of time to reach peak levels in the body.  The immediate-release tablets typically reach peak levels at one and a half hours after administration, while the extended-release tablets may take up to six hours to reach peak levels. It can take up to three months, due to Seroquel mechanism of action, for the full effects of the drug to show.

Take Seroquel As Prescribed

Generally, schizophrenia patients will be placed on a life-long dosage of antipsychotic medication, but it is best to discuss the terms and duration of treatment with a qualified doctor before beginning any dosages.
Doctor discussing elderly patient's mri scans.
The doctor will diagnose and inform the person of all risks, such as using medications that can cause dangerous Seroquel interactions. Even after initial administration, it is important to keep the doctor updated about the situation so the right decision can be made about the correctness of this choice of medication for the patient’s condition.
A known side-effect of Seroquel is its sedative qualities, and these effects generally show up almost immediately. Thus, Seroquel abuse or overdose on this drug will significantly increase these side effects. When dosing on the drug, one must note that it may take up to a few weeks to see any improvements in other symptoms and up to a couple of months to see the full effects of the drug begin to show. One of the more long-term side effects of using the drug is Quetiapine weight gain.
Highlights of the things to note before starting Seroquel treatment include:

  • Symptoms such as delusion, hallucinations, and disorganized thinking are likely to improve within the first couple of weeks.
  • In some cases, the symptoms do not completely go away, and they can only be managed with the appropriate use of the medication.
  • Quetiapine may increase the level of a hormone called prolactin in the blood; thus, Seroquel sexual side effects are the point to take care about.
  • It may take up to a couple of weeks for the user to feel any need to share company with other people, and this will also continue to improve as time passes.
  • The same rule applies to all other symptoms. The more time passes with each dose used at the prescribed times, the better the symptoms get.

It is relatively easy to get a prescription if a physician’s diagnosis states a need for it – the price is reasonable and can be reduced further with Seroquel coupons on the market. Even if taking quetiapine for medical reasons, addiction to this medication can occur. This condition should not be taken lightly. Immediate treatment should be started at a professional rehabilitation center to get rid of the tolerance to the drug and avoid an overdose.

Page Sources

  1. U.S. National Library of Medicine: National Center for Biotechnology Information, Compound Summary: Quetiapine,
  2. Jasdave S. Maan; Abdolreza Saadabadi, Quetiapine,
  3. U.S. Food and Drugs Administration, SEROQUEL (quetiapine fumarate) TABLETS ,,016_seroquel_lbl.pdf

Published on: February 19th, 2020

Updated on: June 3rd, 2020


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