is a benzodiazepine with anxiolytic, euphoric, anticonvulsant, amnestic, muscle relaxant
, and hypnotic (sleep-inducing) effects. Effects last over 60 hours and in case of overdose many days or weeks. Its extreme potency, the urge to redose, 3 hour delay of effects, amnestic and loss of inhibitions makes overdose common. Its English name is a transliteration of the Russian Феназепам. Alternate spellings: 'fenazepam', 'phenazeram'.
[top]Introduction to Phenazepam
Phenazepam is a long acting benzodiazepine
with anxiolytic, euphoric, anticonvulsant, amnestic, muscle relaxant, and hypnotic (sleep-inducing) effects. Its English name is a transliteration of the Russian Феназепам
. Alternate spellings: 'fenazepam', 'phenazeram'.
In Russia and other CIS countries phenazepam is currently used (prescribed) for procedural sedation [a DF member's report of intravenous phenazepam in dentistry]
, as an adjunct to anesthesia, as an anticonvulsant, for the treatment of alcohol
withdrawal syndromes, for the treatment of anxiety and panic disorders, and as a hypnotic. In Europe and North America it is used recreationally as a research chemical
. Active doses start at 0.5 mg. It has comparable potency by weight with flunitrazepam
) and lorazepam
Importation into the UK was banned by the Advisory Council on the Misuse of Drugs
(ACMD) on 22nd July 2011, through amendment to the Open General Import Licence. It is illegal to market Phenazepam in the UK, and the ACMD has recommended that phenazepam be controlled under the Misuse of Drugs Act 1971 as a Class C substance and scheduled as a schedule III substance under the Misuse of Drugs Regulations 2001.
In the US, it is currently not controlled by the Federal Analog Act
, which it is argued applies to only schedule I and II substances. As an uncontrolled benzodiazepine, possession without authority is not considered illegal by the majority of sources, however there are fears that the wording "with like effect" could be used to prosecute users as rohypnol and phenazepam have a similar side effect
In Australia, the states of Victoria and South Australia have passed an Analog Act
under which phenazepam is a controlled substance (analog to existant benzodiazepines
[top]Ways of administration:
[top]Effects of Phenazepam
Phenazepam reaches a peak in effects in 2 to 4 hours. It has anxiolytic (anti-anxiety) effects in therapeutic doses, but can cause dizziness, loss of coordination, drowsiness, and anterograde amnesia with higher doses. Some users report double vision, sometimes severe. At very high doses, delirium and psychosis-like behavior have been reported.
The effect of any size dose will depend in part on the pre-existing benzodiazpine tolerance of the user. A user without any tolerance may notice effects when taking less than a milligram. One user with a very high benzodiazepine tolerance reported that he used oral doses of 100 mg, an amount likely to cause coma or delirium in a user without tolerance.
Opinions differ on whether phenazepam is euphoric. Some have called it one of the most euphoric of the benzodiazepines. Others have said it is not euphoric. One user reports that phenazepam is only euphoric when used intravenously.
[top]Combinations with Phenazepam
Note: these combinations have been reported by users. Being listed here does not constitute a recommendation. These drug combinations may be dangerous.
Phenazepam combined with ketamine
. Result is described as 'wacky'.
Phenazepam combined with sustained-release oxycodone
, and oxycodone-paracetamol.
Phenazepam and 'any dissociative'; 4-Meo-PCP
Phenazepam combined with DOx, 2C-I or 2C-P.
, wormwood, and ketamine. The individual had taken phenazepam 36 hours previously.
Phenazepam and desoxypipradol.
[top]Different Uses for Phenazepam
Phenazepam has been used to self-medicate for insomnia and anxiety. Phenazepam has been both recommended and discouraged for the self-management of alcohol withdrawal. Phenazepam has been used to counter the effects of opiate
withdrawal. Phenazepam has been used for relief of back pain attributed to muscle spasm.
A detailed diary of a successful self-managed detox from opiate addiction using kratom and phenazepam.
Phenazepam has been used to counter excess stimulation, anxiety or wakefulness from stimulant
- 1-2 mg to 'abort' the end of a psychedelic experience when sleep is desired.
- To counter anxiety from MDPV use.
- To come down from Adderal.
- Combined with tetrazepam, to come down from amphetamine or 4-fluoroamphetamine, alcohol and marijuana.
[top]Pharmacology of Phenazepam
Intravenous phenazepam has been reported have the same pharmacokinetics as intramuscular, with 0.82 bioavailability.
Phenazepam pharmacokinetics in humans differs significantly from that of rats, cats, and dogs. 3-OH-phenazepam was not detected in human blood at any time after administration. However, its presence cannot entirely be ruled out as the the analysis techniques used by Zherdev (1982) only tested for the presence of 3 ng/ml or more, and 3-OH-phenazepam was detected in urine .
Phenazepam has a long half-life
compared both to other benzodiazepines, and to most other pharmacologically active substances. After a single dose of 3 mg and 5 mg phenazepam in man, blood concentration vs time curves indicated a half life about 60 hours. Most commonly encountered benzodiazepines have half-lives ranging from 5 to 15 hours. Peak concentrations in humans do not occur until about 4 hours after initial administration.
The species-specific concentration-time curve of the 3-hydroxylated metabolite is important to note. Peak concentrations in the rat occurred 2 hours after administration and constituted 50% of the initial dose of phenazepam. Concentrations of 3-OH-phenazepam decrease rapidly and are negligible after only about 4 hours. In the cat, 3-OH-phenazepam accumulates slowly over about 20 hours after initial administration and concentrations decrease at a slower rate than that of phenazepam .
It has been reported by DF members that common clinical urine drug tests for benzodiazepines detect phenazepam.
The metabolism of phenazepam is similar to that of O-chloro-N-desmethyl diazepam
. According to Zherdev (1982), the metabolic pathway induces the formation of aromatically oxidized metabolites. Specifically mentioned is the 3-hydroxylated metabolite 3-OH-phenazepam. This is an important point as 3-hydroxylated metabolites of some other benzodiazepines are active .
[top]The dangers of Phenazepam
Benzodiazepines taken orally have an excellent safety profile with respect to respiratory and cardiovascular complications. In mice the oral LD50
of phenazepam is 2400 mg/kg. Even a massive oral benzodiazepine overdose is unlikely to cause death if the user does not have other depressant drugs in their system
, and if good nursing care is provided in hospital.
Combining benzodiazepines with other CNS depressant drugs, such as opiates, alcohol, or barbiturates, can cause respiratory depression and death.
- A combination of phenazepam with other benzodiazepines and etaqualone caused coma and nearly caused death in a recreational drug user.
[top]Two deaths due to co-ingestion of phenazepam with opiates or opioids
- In September 2010, a Georgia (USA) 18-year-old died after using a combination of phenazepam and oxycodone. Three other individuals in the same incident were hospitalized.
- In October 2010, a second death was reported in Charleston, West Virginia, USA. A 42-year-old man died after ingesting both phenazepam and poppy tea. A detailed medical examiner's report has been published.[81-82] The victim had a history of alcoholism and asthma. Papaver somniferum pods and a nearly-empty vial of phenazepam were found near his body, and utensils for making tea from the pods. Phenazepam was present in the victim's blood at a concentration of 386 ng/ml, morphine at 116 ng/ml, codeine at 85 ng/ml, and thebaine at 72 ng/ml. The latter three compounds are naturally occurring alkaloids in opium poppies. Hydrocodone was present in the victim's urine. No alcohol was detected.
It is notable that the concentration of phenazepam in this victim's blood was only a third of the amount present in the blood of the patient described below, seven days after phenazepam ingestion. The patient in the latter case survived without apparent injury. This emphasizes that a benzodiazepine overdose that would likely be survivable may become fatal if opiates are co-ingested.
[top]Overdose and Duration Issues
Compared with other benzodiazepines, overdoses with phenazepam are both more likely and more problematic for these reasons:
Extreme caution is urged in using phenazepam. Reports of inadvertent overdose disasters are common.
- Phenazepam is exceptionally potent. Active doses start at less than one milligram.
- Compared to prescription benzodiazepines that have been diverted from regulated channels, phenazepam is inexpensive, and rarely sold in quantities of less than 100 mg. Any user who can afford to buy this drug will be buying a dose capable of causing prolonged coma.
- Phenazepam is most commonly sold in powdered form, which is more difficult to measure than tablets or capsules manufactured to contain a single dose.
- The visual appearance of a dangerous dose is not impressive. The visual size of a 2 mg alprazolam (Xanax) bar is about the same as half a gram of phenazopam. If the user is accustomed to dealing with benzodiazepines in the form of tablets or bars and attempts to 'eyeball' an amount of phenazepam that looks similar, or is even a tenth as large, they will take a massive overdose. Likewise, snorting a 'line' of phenazepam similar in size to a line of cocaine or heroin is likely to produce an overdose.
- Phenazepam's effects are often delayed by 2-3 hours. The inexperienced user, noticing no effects within the first hour, may believe they have taken too little and re-dose, resulting in an overdose.
- Phenazepam's 60 hour half-life makes dosing mistakes hard to recover from. The overdose will last for days, possibly weeks.
These are descriptions of phenazepam overdoses that have been posted to Drugs-Forum:
"One report flew in of someone who eyeballed the molecule. Said to have spent 2 days flat as a pancake."
"Recently, a friend of SWIM
reported that unknown amount of the substance had been nasally administered at the tail of after a powerful and problematic br-dfly-trip... Tragic mistake. Friend of SWIM showed up unannounced at SWIM's door in a state akin to temporary psychosis several times that week, disinhibited and amnesiac. After a week SWIM's friend had come out of the constant phenazepam clouds and was able to explain more clearly what had went wrong during the br-dfly trip and so on, to the relief of SWIM who had begun to really worry after a couple of days."
"Swim ended up going to work completely blacked out, looking like a zombie for two days in a row. He ended up going to the hospital, at the urging of friends who had no idea what was wrong with him. He scared the shit out of his family and girlfriend who thought he had a brain tumor or stroke or something else horrible. He also was scared as shit because when he came out of the blackout he couldn't think straight or remember anything, especially not that he was high and the reason he was in the hospital."
"Swim and a friend blacked out entire junior year of high school on phenazepam. No matter how much you take after a while, you wont get high. Just relaxed and then when you finally take enough to get high you automatically forget everything."
"SWIM gets 100mg Phenazepam No scale, hadn't had Xanax for over a week so I eyeball a pencap. Go to work feel good, make a delivery not quite what SWIM wanted so he went to the bathroom and eyeballed about the same size cap. THe night goes on very well, almost over got to take this last delivery less than a mile then SWIM's home free, I believe SWIM said let's make this a good one and I believe SWIM took a dose larger than the first two. After that memory is blurry. En train of events apparently 3 hours later the cops find SWIm crashed in a ditch unconscious."
[top]Report of a massive oral overdose
There is one reported case of a 26 year old man with Asperger's Syndrome who consumed between 400 and 600 mg of phenazepam. The author estimates this to be 500 times the recommended daily dose. When admitted to the hospital, "he was slow, slurred his words, and had balance problems; his parents also reported fluctuating confusion and memory disturbances." When the doctors examined him he appeared to be under the influence of alcohol, which is not surprising since benzodiazepines mediate levels of GABA
in the brain in a manner similar to alcohol.
A CT scan was normal. A urine sample tested positive for benzodiazepines.
The man had a history of excessive use of alcohol to control his anxiety and severe depression. He was also currently prescribed venlafaxine
A few days after taking phenazepam he developed auditory and visual hallucinations, but details of the severity were not provided from the case report. He was administered flumazenil, a benzodiazepine antagonist, and activated charcoal repeatedly but his symptoms did not improve. He remained hospitalized for 11 days. His condition fluctuated. On the 9th day he was able to recall that he ordered the drug on the internet.
For further care, he was referred to a psychiatric unit. A test showed that 7 days post administration of the phenazepam there was a 1.2µg/g concentration of phenazepam in his blood, venlafaxine within therapeutic limits, and no alcohol. Link to report of this case.
[top]Dangerous Mental Side Effects
A frequent theme in reports of overdose with phenazepam is a dramatic change in the personality of the drug user while intoxicated. This may be due to the relaxation of inhibitions, which is a common feature of drugs which increase the effects of GABA. Users who have taken large doses of this drug often report that under its influence they have acted in ways they would consider unethical or unreasonably risky when sober. One user reported with anguish that he sold his girlfriend's sexual services to his drug dealer. Another reported multiple encounters with police, incarceration, and a wrecked car during a few weeks of using phenazepam in unmeasured high doses. This user's girlfriend, who also used the drug for a relatively short time, under its influence began to work as a prostitute and initiated a sexual relationship with another woman.
Anterograde amnesia is also a prominent feature of overdose reports. This is a well-known effect of most benzodiazepines if used in high doses. The user mentioned above who sold his girlfriend to his drug dealer had no memory of the event when he was told about it by others.
[top]Toxicity of Inhaled Phenazepam
Inhaling smoked phenazepam presents unique risks due to pyrolysis. When heated to decomposition phenazepam emits fumes of chlorine, bromine, and nitrogen oxide/nitrogen dioxide. All are toxic.
[top]The Urge to Re-dose
Some users find the effects of phenazepam so compelling that they want to re-dose whenever those effects ebb. Because phenazepam suppresses inhibitions and impairs judgment, the desire to re-dose is more likely to be acted on. This can result in a cycle of re-dosing that may lead to increasing drug tolerance, the use of ever-increasing amounts of phenazepam, and ultimately addiction
This passage illustrates such a re-dosing cycle, resulting in a very high amount of phenazepam consumed in a short time:
"Last monday SWin got hold of 0.5g phenazepam. as SWIM was impatient SWIM dippet a moist toothpick in it and then licked it, got mild effects. then swim upped the dose and allmost all of it's gone and and swim actually managed to go to school while under influence(swim told people who asked why i was lookin a bit tired and told then that i had been drinkin heavily each night...)"
The actions of the individuals in this famous story of phenazepam use fit the same pattern of compulsive re-dosing.
Like other benzodiazepines, the addiction potential of phenazepam is very high. Neurochemical changes from the chronic use of benzodiazepines was noted as early as 1981.[Medical Research Council Benzodiazepine Dependence
] These alterations created a physical dependence on the drug which may become dangerous if use is stopped abruptly.
symptoms range from restlessness, anxiety, and insomnia to convulsions or seizures. Rarely, death may occur during inadequately treated withdrawal from benzodiazepines. Withdrawal symptoms worse than mild anxiety should be treated with the assistance of a physician. A tapered dose of a benzodiazepine may be prescribed. Admission to hospital is necessary for severe symptoms.
|Systematic (IUPAC) name:||7-Bromo-5-(2-chlorophenyl)-1,3-dihydro-2H-1,4-benzodiazepin-2-one|
|Molar mass:||349.61 g/mol |
|CAS Registry Number:||51753-57-2|
|Boiling Point:||no data|
|Flash Point:||no data|
|Solubility:||Soluble in propylene glycol, 1 mg:1 ml. Soluble in DMSO. Reported to be soluble in chloroform and acetone. Moderately soluble in isopropyl alcohol. Reported to be soluble in PEG. Reports of solubility in 95% ethanol vary. Insoluble in water or ether.|
|See Phenazepam solubility for more information.|| |
|Additionnal data:||density 1.61 g/mL|
|Notes:||Aspect : white or off-white crystalline powder|
[top]Legal status of Phenazepam
Phenazepam is not scheduled in the 1971 United Nations Convention on Psychotropic
Phenazepam is not an FDA approved drug product. It is not legal to market phenazepam in the US as a drug, or include it in a food product. Phenazepam is not scheduled by the DEA, and because no benzodiazepine is in DEA Schedule I or II
, it does not fall under the Controlled Substance Analog Enforcement Act of 1986. [21 U.S.C. 802(32), 21 U.S.C. § 813]
Analog Act DF wiki
Phenazepam is not licensed by the European Medicines Agency. Phenazepam is not controlled at the EU level. Some individual countries have national laws regarding it.
Phenazepam is a Schedule IV substance under the Narcotic Drugs and Psychotropic Substances Act. Schedule IV is the lowest classification of psychoactive
substances in Estonia. It includes prescribable drugs, including other benzodiazpines. It appears to be concordant with Schedule IV in the UN Convention on Psychotropic Substances.
Phenazepam is a Schedule III substance under Cabinet Regulation N 35, "Regulation on lists of controlled narcotic substances, psychotropic substances and precursors." Schedule III is the lowest classification of active psychoactive substances in Latvia. Schedule III includes prescribable drugs, including other benzodiazpines and barbiturates.
Phenazepam is a Schedule III substance under the The Law on the Control of Narcotic and Psychotropic Substances. Schedule III is the lowest classification of psychoactive substances in Lithuania. Schedule III includes prescribable drugs.
Republic of Ireland
: Phenazepam apparently falls under the Criminal Justice (Psychoactive Substances) Act of 2010, in effect since August 23, 2010. This act makes it illegal to "sell or supply for human consumption substances which are not specifically prescribed under the Misuse of Drugs Acts, but which have psychoactive effects."
Phenazepam was classified in 2008 as a narcotic under the The Ordinance on Prohibition of Certain Goods Dangerous to Health.
Phenazepam is not currently listed in the Misuse of Drugs Act of 2001, or subsequent amendments although came under an import ban as of 22nd July 2011 and is soon to be controlled under Misuse of Drugs Act on advice of ACMD. It is not approved as a medicine by the Medicines and Healthcare Products Regulatory Agency.
: Phenazepam is not listed in the Controlled Drugs and Substances Act.
Phenazepam is not reported to be controlled in China.
Phenazepam is not listed among "narcotics
, drugs, psychotropic substances & precursor chemicals" that are controlled.
The Resolution of the Government of the Republic of Moldova No 79 lists drugs the possession of which is considered a 'drug-related crime or a drug-related administrative offence'. Phenazepam was added to this list in 2008.
as of March 24, 2010, phenazepam is considered a 'narcotic', in common with most other benzodiazepines. It cannot be prescribed by physicians.
: Phenazepam is available by a physician's prescription, but does not appear in this list of controlled substances
, dated 2008. It has been informally reported on the net that phenazepam is available at some pharmacies without a prescription.
[top]History of Phenazepam
: Phenazepam is first synthesized in the USSR through a collaborative effort betweeny pharmacologists from the Academy of Medical Sciences of the USSR and chemists at I. I. Mechnikov Odessa National University in Ukraine.
: Phenazepam is first mentioned in the Russian medical literature. Both papers describe it as 'new'. It is proposed for use in 'neurotic conditions'.
Russian literature reports the use of phenazepam as pre-medication for oral surgery.
Russian literature reports the use of phenazepam in psychotic patients with anxiety, and as an anticonvulsant (anti-epilepsy) drug. Its properties an an anticonvulsant are described as being similar to those of clonazepam
A Russian report mentions the use of phenazepam in depersonalization disorder (a symptom of anxiety or depression).
: A Russian paper recommends the use of phenazepam as a hypnotic.
: Russian literature describes the use of phenazepam in combination drug therapy for prevention of phantom pain syndrome after amputation.
: First English language posting to Usenet mentioning phenazepam in a non-prescription context.
Russian literature describes transdermal administration of phenazepam.
Phenazepam is reported as a new recreational drug in Finland: "Phenazepam in a new benzodiazepine derivative that was found on illegal drug markets in Finland... In year 2003 there were 20 positive phenazepam cases [among intoxicated drivers]."
First mention of phenazepam on Drugs-Forum.
Phenazepam in non-prescription use available as tablets, source believed to be Russia.
Phenazepam is available in the UK as a powder.
A recreational phenazepam ovedose is reported in Sweden.
Phenazepam found as the psychoactive ingredient in blotter prints submitted to the DEA as suspected LSD.[19,32]
First reported US deaths related to phenazepam, both in combination with opiates. An 18 year old male died after using phenazepam together with oxycontin, and a 42 year old man died after using both phenazepam and poppy tea.
Post & read experiences with Phenazepam.
[top]Recent Drugs-Forum threads mentioning phenazepam
Calculated from Atomic Weights of the Elements
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