- See dextromethorphan for info on the medical use of DXM and its chemical, pharmacological and other misc information.
Dextromethorphan or DXM, an active ingredient found in most cough suppressant cold medicines, is commonly used as a recreational drug. While having almost no psychotomimetic effects at medically-recommended doses, dextromethorphan has euphoric, hallucinogenic, and dissociative properties when administered in doses well above those which are considered therapeutic medically for cough suppression.
An online essay first published in 1995, entitled "The DXM FAQ", was possibly the first source of specific scientific details regarding dextromethorphan's potential for recreational use. This may have led to a number of "underground" websites in existence today, devoted to the topic of dextromethorphan as a recreational drug.
Due to abuse and theft concerns, many retailers in the US have moved dextromethorphan-containing products behind the counter so that one must ask a pharmacist to receive them or be 18 years (19 in NJ and AL) or older to purchase them. Some retailers also give out printed recommendations about the potential for abuse with the purchase of products containing dextromethorphan.
At high doses, dextromethorphan is classified as a dissociative anesthetic, similar to the controlled substances ketamine
(PCP). Also like those drugs, dextromethorphan is an NMDA receptor antagonist
Dextromethorphan generally does not produce withdrawal symptoms characteristic of physically addictive substances, but there have been cases of psychological addiction.
Antitussive preparations containing dextromethorphan are legal to purchase from most pharmacies worldwide. Since dextromethorphan's use as a recreational drug usually involves only the ingestion of large quantities of an over-the-counter medication, no legal distinction currently exists between medical and recreational use, sale, or purchase.
The sale of dextromethorphan in its pure powder form may incur penalties in the United States, although no explicit law exists prohibiting its sale. There have been cases of individuals incurring time in prison and other penalties for selling pure dextromethorphan in this form, due to the incidental breaking of related drug laws — such as resale of a medication without proper warning labels.
Dextromethorphan was excluded from the Controlled Substances Act (CSA) of 1970 and was specifically excluded from the Single Convention on Narcotic Drugs. Dextromethorphan is still excluded from the CSA (as of 2008), however officials have warned that it could still be added if increased abuse warrants its scheduling.
Dextromethorphan is generally available over the counter in most countries, with two exceptions being Hong Kong and Sweden.
Dextromethorphan, when consumed in low "recreational doses" (usually around or slightly more than 200 mg, or around 1.5 to 2.5 mg/kg), is described as having a euphoric effect. With middle doses (about 400 mg, or 2.5 to 7.5 mg/kg), intense euphoria
), vivid imagination, and closed-eye hallucinations
may occur. With high doses (600 mg, or 7.5 mg/kg and over), profound alterations in consciousness have been noted, and users often report out-of-body experiences or temporary psychosis. Frequent and long-term usage at very high doses could possibly lead to toxic psychosis
and other permanent psychological problems. Most users find such high doses to be extremely uncomfortable and are unwilling to repeat them. Flanging
(speeding up or slowing down) of sensory input is also a characteristic effect of recreational use.
There may also be a marked difference between dextromethorphan hydrobromide, contained in most cough suppressant preparations, and dextromethorphan polistirex, contained in the brand name preparation Delsym. Polistirex is an edible plastic surrounding the dextromethorphan molecule, allowing for timed release as the stomach acids break down the plastic. As a cough suppressant, the polistirex version lasts up to 12 hours, so this duration may also hold true when used recreationally.
In 1981, a paper by Gosselin estimated the lethal dose to be between 50 and 500 mg/kg. Doses as high as 15-20 mg/kg are taken by some recreational users. It is suggested by a single case study that the antidote to dextromethorphan overdose is naloxone, administered intravenously.
In addition to producing PCP-like behavioral effects, high doses may cause a false-positive result for PCP and opiates in some drug tests.
Risks associated with abuse
Most risks result from abusing multi-symptom cold medications, rather than using a cough suppressant whose sole active ingredient is dextromethorphan. Abusing medications with multiple active ingredients can produce negative psychological and physiological effects and is highly unsafe. Multi-symptom cold medicines contain other active ingredients, such as acetaminophen
, and phenylephrine
, any of which can cause permanent bodily damage, or even death, if taken on the generally-accepted recreational dosing scale of dextromethorphan. Guaifenesin
, an expectorant
commonly accompanying dextromethorphan in cough preparations, is also dangerous if taken on dextromethorphan's recreational dosing scale and can cause vomiting, upset stomach, and headache.
Combining dextromethorphan with other substances can compound risks. Stimulants such as amphetamine and/or cocaine can cause a dangerous rise in blood pressure and heart rate. CNS depressants such as ethanol (drinking alcohol) will have a combined depressant effect, which can cause a decreased respiratory rate. Combining dextromethorphan with other CYP2D6 substrates can also cause both drugs to build to dangerous levels in the bloodstream.
The "DXM FAQ"
A document entitled "The DXM FAQ," by William E. White
, classifies dextromethorphan's high-dose effects into four plateaus
, each defined by a dosing range. The dosages are specified in ratios of milligrams
(of the drug) per kilogram
(of one's body mass). According to the FAQ
, the plateaus occur as follows:
- First plateau: At a dosage of 1.5 to 2.5 mg/kg, effects include a sensation of alertness, stimulant effects such as restlessness, increased heartbeat, and increased body temperature, intensification of emotions, general euphoria, euphoria linked to music, alteration of sensations of gravity, loss of balance, slight intoxication, and for some users nausea.
- Second plateau: At 2.5 to 7.5 mg/kg, effects include the same effects of the first plateau, with added choppy sensory input, entering a dreamlike state of consciousness, increasing detachment from outside world, a heavier "stoned" feeling than with first plateau, and/or closed-eye hallucinations.
- Third plateau: At 7.5 to 15.0 mg/kg, effects include flanging of visual effects, difficulty recognizing people or objects, chaotic blindness, dreamlike vision, inability to comprehend language, abstract hallucinations, delayed reaction time, decision making impairment, feelings of peace and quiet, near complete loss of motor coordination, short term memory impairment, and/or feelings of rebirth.
- Fourth plateau: At 15.0 mg/kg or more, an individual may experience a perceived loss of contact with their own body, changes in visual perception, out-of-body experiences, perceptions of contact with "superior," supernatural, or other archetypal beings (ie. gods, aliens, vampires, etc.), other miscellaneous delusions, lack of movement or desire to move, rapid heart rate, complete blindness, increased hearing, and intensification of third plateau effects.
Dextromethorphan's psychological effects can be attributed largely to dextrorphan
(DXO), a metabolite
produced when dextromethorphan metabolizes within the body. Both dextrorphan and
dextromethorphan are NMDA receptor antagonists
, just like the dissociative hallucinogenic drugs ketamine
(PCP); however for that purpose, dextrorphan is more potent than dextromethorphan.
Just like all NMDA receptor antagonists, dextrorphan and dextromethorpan inhibit a neurotransmitter called glutamate from activating receptors in the brain. This can effectively slow or even shut down certain neural pathways, preventing areas of the brain from communicating with each other. This leaves the user feeling dissociated (disconnected) or "out-of-body".
Dextromethorphan's euphoric effects have sometimes been attributed to the triggering of an increase in dopamine levels, since such an increase generally correlates to a pleasurable response to a drug, as is observed with antidepressants. However the effect of dextrorphan and dextromethorphan on dopamine levels is a disputed subject. Studies show that some NMDA receptor antagonists, like ketamine and PCP, do raise dopamine levels. Other studies show that dizocilpine, another NMDA receptor antagonist, has no effect on dopamine levels. Some findings even suggest that dextromethorphan actually counters the dopamine increase caused by morphine. Due to these conflicting results, the actual effect of dextromethorphan on dopamine levels is yet to be determined.