Quetiapine

Quetiapine is an atypical antipsychotic drug and dibenzothiazepine derivative. Quetiapine contains a thiazepine ring, a seven-membered ring containing one sulfur and one nitrogen group, located at R₁ and R₄ respectively. This ring is fused to two benzene rings, thus forming a dibenzothiazepine moiety. Dibenzothiazepine is connected at R₁₁ to the nitrogen group of a piperidine ring at R₄.

Piperazine is a six-member unsaturated ring with two nitrogen constituents in the 1,4 positions. This ring is connected at its second nitrogen group to an ethoxyethanol chain. It is connected to R₂ of an ethane chain through an oxygen bridge to an ethanol group. This forms the structure of quetiapine.

It is commonly synthesized by nucleophilic substitution to combine the dibenzothiazepine core with the rest of the structure. Quetiapine is present in its pill form as a fumarate salt.

Quetiapine is a powerful dopaminergic, serotonergic, and adrenergic antagonist, as well as a potent antihistamine with clinically negligible anticholinergic properties.^{[8][9][10][11]} Quetiapine binds strongly to serotonin receptors; the drug acts as partial agonist at 5-HT1A receptors.^[12] In terms of its antipsychotic effects, the precise mechanism of action is unknown, but according to the dopamine theory of schizophrenia, antipsychotic effects might be related to the drug’s ability to reduce dopaminergic neurotransmission within the mesolimbic pathway.

Disclaimer: The effects listed below cite the Subjective Effect Index (SEI), a literature based on anecdotal reports and the personal experiences of PsychonautWiki contributors. As a result, they should be treated with a healthy amount of skepticism. It is worth noting that these effects will not necessarily occur in a consistent or reliable manner, although higher doses are more likely to induce the full spectrum of effects. Likewise, adverse effects become much more likely with higher doses and may include serious injury or death.

Experience reports

Anecdotal reports which describe the effects of this compound within our experience index include:

• Experience:25mg Quetiapine - Nice buzz

Additional experience reports can be found here:

• Erowid Experience Vaults: Quetiapine

• Schizophrenia: There is tentative evidence of the benefit of quetiapine versus placebo in schizophrenia; however, definitive conclusions are not possible due to the high rate of attrition in trials (greater than 50%) and the lack of data on economic outcomes, social functioning, or quality of life.^[13]
• Bipolar disorder: In those with bipolar disorder, quetiapine is used to treat depressive episodes and acute manic episodes associated with bipolar I disorder.^[14][15]
• Major depressive disorder: Quetiapine is effective when used by itself and when used along with other medications in major depressive disorder (MDD).^[16][17] However, sedation is often an undesirable side effect.^[18]
• Parkinsons disease: Quetiapine and clozapine are the most widely used medications for the treatment of Parkinson's disease psychosis due to their very low extrapyramidal side effect liability. Owing to the risks associated with clozapine (e.g., agranulocytosis, diabetes mellitus, etc.), clinicians often attempt treatment with quetiapine first, although the evidence to support quetiapine's use for this indication is significantly weaker than that of clozapine.^[19][20]
• Other: The use of low doses of quetiapine for insomnia, while common, is not recommended; there is little evidence of benefit and concerns regarding adverse effects.^[21][22] It is sometimes used off-label, often as an augmentation agent, to treat conditions such as Tourette syndrome,^[23] musical hallucinations^[24] and anxiety disorders.^[25] It is particularly useful as a tool for forced sedation during bad trips or prolonged unwanted stimulation.

Quetiapine likely has a low toxicity relative to dose. Although simply trying this substance at a low to moderate dosage is considered as quite safe, there is an emerging controversy regarding quetiapine fatalities. Approximately 10,000^[26] lawsuits^[27][28][29] against AstraZeneca for problems ranging from slurred speech and chronic insomnia to death have been filed by individuals from civilian populations.

Both typical and atypical antipsychotics can cause tardive dyskinesia.^[30] According to one study, rates are lower with the atypicals at 3.9% as opposed to the typicals at 5.5%.^[31] Although quetiapine and clozapine are atypical antipsychotics, switching to these atypicals is an option to minimize symptoms of tardive dyskinesia caused by other atypicals.^[32]

Weight gain can be a problem for some, with quetiapine causing more weight gain than other more commonly used antipsychotics.^[33]

It is strongly recommended that one use harm reduction practices when using this drug.

Lethal dosage

Compared to other antipsychotics, quetiapine has been reported to be relatively safer in overdose.^[34] Most instances of acute overdoses result only in sedation, hypotension and tachycardia, but cardiac arrythmia, coma and death have occurred in adults. Quetiapine concentrations within the patients' blood are usually in the 1–10 mg/L range in overdose survivors, while postmortem blood levels of 10–25 mg/L are generally observed in fatal cases.^[35]

Tolerance and addiction potential

Quitiapine is moderately physically and psychologically addictive.

Tolerance will develop to the antipsychotic effects and within a week of continuous use. The tolerance to the amount of sedation will be the most noticeable. After cessation, the tolerance returns to baseline in 7 - 14 days. Withdrawal symptoms or rebound symptoms may occur after ceasing usage abruptly following a few weeks or longer of steady dosing, and may necessitate a gradual dose reduction.

The addictive qualities of quetiapine have not been formally studied and are largely known through anecdotal sources. For example, a letter to the editor that appeared in the January 2007 American Journal of Psychiatry has proposed a “need for additional studies to explore the addiction-potential of quetiapine”. The letter reports that its authors are physicians who work in the Ohio correctional system. They report that “prisoners have threatened legal action and even suicide when presented with discontinuation of quetiapine” and that they have “not seen similar drug-seeking behavior with other second-generation antipsychotics of comparable efficacy”.

Withdrawal symptoms

Withdrawal symptoms reported to occur after discontinuation of quetiapine and other antipsychotics include nausea, emesis, lightheadedness, diaphoresis, dyskinesia, orthostatic hypotension, tachycardia, insomnia, nervousness, dizziness, headache, excessive non-stop crying, and anxiety.^[36][37] According to Eli Lilly internal documents, discontinuation of atypical neuroleptics similar to seroquel can also cause psoriasis, gingivitis and other inflammatory conditions, dyspepsia, headache, high blood sugar and other health conditions unrelated to psychiatric condition.^[38][39]

• Austria: It is available by prescription only and unscheduled.^{[citation needed]}
• France: It is available by prescription only and unscheduled.^{[citation needed]}
• Germany: Quetiapine is a prescription medicine, according to Anlage 1 AMVV.^[40]
• Switzerland: Quetiapine is listed as a "Abgabekategorie B" pharmaceutical, which requires a prescription.^{[citation needed]}
• United Kingdom: Available by prescription only - unscheduled, but unpopular.^{[citation needed]}
• United States: Quetiapine (Seroquel) is unscheduled in the United States, but is available by prescription only. This means that sales and distribution are allowed only by those with a license and only to those with a prescription (according to FDA regulations). Possession is not illegal even without a prescription.^{[citation needed]}

• Responsible use
• Depressants
• Antipsychotics

• Quetiapine (Wikipedia)
• Quetiapine (Erowid Vault)
• Quetiapine (TiHKAL / Isomer Design)