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Additionally, promethazine is an anticholinergic, and at high doses it may cause delirium and extremely unpleasant if not dangerous experiences. Please be extremely careful when trying this pharmaceutical and use responsible use practices such as always having a tripsitter when using promethazine, especially at high doses.
|Summary sheet: Chlorpheniramine|
|Common names||Chlorphenamine, Chlor-Trimeon|
|Psychoactive class||Depressant / Deliriant|
|Routes of Administration|
Chlorpheniramine (commonly sold as Chlor-Trimeton is a first-generation antihistamine of the alkylamine chemical class that produces muscle relaxing, nausea relieving and sedative effects when administered. It also reduces motion sickness and has anticholinergic properties.
Chlorphenamine was patented in 1948 and came into medical use in 1949. It is available as a generic medication and over the counter.
Today, Chlorphenamine is available in many countries under many brand names, it has been shown to have some hypnotic effects and is sometimes used off-label for this purpose.
History and culture
This History and culture section is a stub.
As a result, it may contain incomplete or wrong information. You can help by expanding it.
Brand names have included Demazin, Allerest 12 Hour, Codral Nighttime, Chlornade, Contac 12 Hour, Exchange Select Allergy Multi-Symptom, A. R. M. Allergy Relief, Ordrine, Ornade Spansules, Piriton, Teldrin, Triaminic, and Tylenol Cold/Allergy.
Chlorphenamine is a alkylamine-based compound.
Chlorphenamine acts primarily as a potent H1 antihistamine. It is specifically a potent inverse agonist of the histamine H1 receptor. The drug is also commonly described as possessing weak anticholinergic activity by acting as an antagonist of the muscarinic acetylcholine receptors. The dextrorotatory stereoisomer, dexchlorpheniramine, has been reported to possess Kd values of 15 nM for the H1 receptor and 1,300 nM for the muscarinic acetylcholine receptors in human brain tissue. The smaller the Kd value, the greater the binding affinity of the ligand for its target.
In addition to acting as an inverse agonist at the H1 receptor, chlorphenamine has been found to act as a serotonin reuptake inhibitor (Kd = 15.2 nM for the serotonin transporter). It has only weak affinity for the norepinephrine and dopamine transporters (Kd = 1,440 nM and 1,060 nM, respectively).A similar antihistamine, brompheniramine, led to the discovery of the selective serotonin reuptake inhibitor (SSRI) zimelidine.
Disclaimer: The effects listed below cite the Subjective Effect Index (SEI), a research literature based on anecdotal reports and the personal experiences of PsychonautWiki contributors. As a result, they should be regarded with a healthy degree of skepticism. It is worth noting that these effects will not necessarily occur in a predictable or reliable manner, although higher doses are more liable to induce the full spectrum of effects. Likewise, adverse effects become much more likely with higher doses and may include addiction, serious injury, or death.
- Sedation - Chlorphenamine causes strong sedation and a feeling of slowness and confusion, usually with the feeling of not wanting to move, this effect is normally stronger than diphenhydramine (Benadryl) but weaker than that of doxylamine (Unisom) and promethazine (Phenergan).
- Muscle relaxation - this effect is weaker than commonly used muscle relaxers such as diazepam (Valium) and carisoprodol (Soma)
- Increased heart rate and increased blood pressure- Anticholinergic activity at muscarinic acetylcholine receptors causes these effects.
- Abnormal heartbeat - This effect is exceptionally rare.
- Nausea suppression - Promethazine is used to treat motion sickness or nausea.
- Dry mouth - This is a common side effect of this substance.
- Difficulty urinating - This side effect is uncommon.
- Anxiety - Promethazine can occasionaly cause paranoia and Anxiety due to delirium although it is rarer than that of Diphenhydramine, Doxylamine and chlorpheniramine.
- Euphoria - Usually, promethazine causes minimal euphoria normally only in anxious individuals and can even be dysphoric, however when used at low doses and combined with an opioid such as codeine, oxycodone or hydrocodone, it can effectively potentiate the euphoric effect and allow for a lower opioid dose.
- Emotion suppression - This effect is mild and occurs due to the mild weak antipsycotic effect, however much weaker than that of chlorpromazine or prochlorperazine.
- Sleepiness - Feelings of physical exhaustion and tiredness are a common and pronounced effect of promethazine. The substance is therefore used to treat insomnia and abnormal sleep cycles.
- Depth perception distortions - This side effect is uncommon.
- External hallucination (autonomous entities; settings, sceneries, and landscapes; perspective hallucinations and scenarios and plots) - The threshold for halucinations on Promethazine is higher than other 1st generation antihistamines like Diphenhydramine and doxylamine, occurs mainly heavy doses and can be difficult to reach due to the user likely falling asleep before they can reach delirium, as Promethazine is extremely sedating at high doses. It can be comprehensively described through its variations as delirious in believability, controllable or autonomous in controllability and solid in style. The most common themes for these hallucinations include those of both everyday occurrences such as smoking phantom cigarettes, talking to people who are not there, seeing and feeling insects and immersion in sinister or nightmarish experiences.
- Internal hallucination (autonomous entities; settings, sceneries, and landscapes; perspective hallucinations and scenarios and plots) - Relative to other hallucinogens, this effect occurs briefly and spontaneously at moderate doses but becomes progressively extended in its occurrence and duration proportional to dosage before eventually becoming all-encompassing. It can be comprehensively described through its variations as delirious in believability, interactive in style, equal in new experiences and memory replays in content, autonomous in controllability and solid in style. Internal hallucinations may occur at lighter dosages than needed to cause external hallucinations and delirium.
- Peripheral information misinterpretation
- Shadow people
- Unspeakable horrors
- Object activation
There are currently no anecdotal reports which describe the effects of this compound within our experience index. Additional experience reports can be found here:
Toxicity and harm potential
This toxicity and harm potential section is a stub.
As such, it may contain incomplete or even dangerously wrong information. You can help by expanding or correcting it.
It is strongly recommended that one use harm reduction practices when using this substance.
The lowest published toxic dose of promethazine in humans (oral) is 3.5 mg/kg. This means that a person weighing 70 kg can show signs of toxicity at 245 mg. The LD50 of promethazine in mice (oral) is 255 mg/kg. If applied to humans, this suggests that 50% of people weighing 70 kg would die after consuming 17.85 grams of promethazine. 
Tolerance and addiction potential
Promethazine is not addictive.
This dangerous interactions section is a stub.
As such, it may contain incomplete or invalid information. You can help by expanding upon or correcting it.
Although many psychoactive substances are reasonably safe to use on their own, they can suddenly become dangerous or even life-threatening when combined with other substances. The following list includes some known dangerous combinations (although it is not guaranteed to include all of them). Independent research (e.g. Google, DuckDuckGo) should always be conducted to ensure that a combination of two or more substances is safe to consume. Some of the listed interactions have been sourced from TripSit. Promethazine, because of its extensive pharmacology, has many interactions. According to the interactions checker on Drugs.com, promethazine is known to interact with over 1000 other prescription and OTC drugs.
- Depressants (1,4-Butanediol, 2-methyl-2-butanol, alcohol, barbiturates, GHB/GBL, methaqualone, opioids) - This combination can result in dangerous or even fatal levels of respiratory depression. These substances potentiate the muscle relaxation, sedation and amnesia caused by one another and can lead to unexpected loss of consciousness at high doses. There is also an increased risk of vomiting during unconsciousness and death from the resulting suffocation. If this occurs, users should try to fall asleep in the recovery position or have a friend move them into it.
- Anti-dopaminergics - Because promethazine also blocks dopamine receptors, other drugs and substances that do this will increase the chances of developing acute or tardive dyskinesia, neuroleptic malignant syndrome, or parkinsonism. 
- Anticholinergics - Promethazine with anticholinergics (or antimuscarinics) can cause increased blocking of acetylcholine, being potentially dangerous with cardiovascular effects as well as delirium. 
- Stimulants - Due to promethazine's excitatory cardiac effect, combining it with stimulants poses a risk of an abnormal heart rhythm, severe tachycardia, or a heart attack as well as other cardiovascular events.
This legality section is a stub.
As such, it may contain incomplete or wrong information. You can help by expanding it.
- Russia: Promethazine is available through a prescription.
- Risks of Combining Depressants (Tripsit) | https://tripsit.me/combining-depressants/
- Tsay, M. E., Procopio, G., Anderson, B. D., & Klein-Schwartz, W. (2015). Abuse and intentional misuse of promethazine reported to US poison centers: 2002 to 2012. Journal of addiction medicine, 9(3), 233-237. | PubMed Link: https://www.ncbi.nlm.nih.gov/pubmed/25822213