|Summary sheet: Carisoprodol|
|Common names||Carisoprodol, Soma|
|Substitutive name||Isopropyl meprobamate|
|Systematic name||[2-(Carbamoyloxymethyl)-2-methylpentyl] N-propan-2-ylcarbamate|
|Routes of Administration|
Carisoprodol, also known by the brand name Soma, is a carbamate sedative-hypnotic. Carisoprodol is used medically as a centrally-acting muscle relaxant, anxiolytic and hypnotic for the short-term treatment of insomnia. Carisoprodol also has weak analgesic effects. Carisoprodol is sometimes found in formulations also containing caffeine and acetaminophen. Carisoprodol produces similar effects to barbiturates. Carisoprodol acts as a prodrug to meprobamate, meaning it is metabolized to meprobamate when it enters the body.
Carisoprodol, like barbiturates, has been primarily replaced by benzodiazepines due to a larger therapeutic window, having less severe adverse effects and being safer in overdose.
Chemically, carisoprodol is classified as a carbamate. It is extremely similar in structure to meprobamate, the only difference being an isopropyl group bonded to an amine group. Carbamates are derivatives of carbamic acid. The empirical formula is carisoprodol is C12H24N2O4 and has a molar mass of 260.33 grams per mole.
Carisoprodol is a prodrug that is metabolized to meprobamate. The precise mechanism of meprobamate is not completely understood. However it is believed that meprobamate acts similarly to benzodiazepines and barbiturates, acting as a positive allosteric modulator of a GABAA receptor. Unlike barbiturates and benzodiazepines, in animal studies meprobamate has been shown to retain most of its effects without having gamma-aminobutyric acid present. Meprobamate has also been noted to be an adenosine reuptake inhibitor, making it unique among hypnotics.
Carisoprodol is metabolized by the cytochrome P450 2C19 enzyme in the liver and has a biological half-life of about two hours. Carisoprodol and its metabolites are excreted by the kidneys in urine.
The effects listed below are based upon the subjective effects index and personal experiences of PsychonautWiki contributors. These effects should be taken with a grain of salt and will rarely (if ever) occur all at once, but heavier doses will increase the chances of inducing a full range of effects. Likewise, adverse effects become much more likely on higher doses and may include serious injury or death.
- Sedation - In terms of energy level alterations, this drug has the potential to be extremely sedating and often results in an overwhelmingly lethargic state. However, compared to barbiturates and benzodiazepines, this effect is not as strong because carisoprodol is an adenosine reuptake inhibitor.
- Motor control loss
- Muscle relaxation
- Respiratory depression
- Physical euphoria - This effect generally occurs only at heavier doses, but may be present at lower doses as well. The euphoria felt on carisoprodol is significantly stronger than that felt on benzodiazepines.
- Decreased libido
- Pain relief - Compared to other agents such as opioids, this effect is generally considered to be quite weak.
- Anxiety suppression
- Cognitive euphoria - Compared to most other depressants, this effect is particularly strong.
- Thought deceleration
- Analysis suppression
- Language suppression - At higher doses, carisoprodol is known cause slurred speech.
- Compulsive redosing
- Delusions of sobriety - This is the false belief that one is perfectly sober despite obvious evidence to the contrary such as severe cognitive impairment and an inability to fully communicate with others. It most commonly occurs at heavy dosages.
Toxicity and harm potential
Carisoprodol likely has moderate toxicity relative to dose. However, carisoprodol is potentially lethal when mixed with depressants like alcohol or opioids. Carisoprodol has been taken off the market is several countries such as Sweden and Indonesia due to side effects and abuse.
It is strongly recommended that one use harm reduction practices when using this drug.
Tolerance and addiction potential
Carisoprodol is extremely physically and psychologically addictive. Carbamate withdrawal, like barbiturate withdrawal, is medically serious and can potentially cause a life-threatening withdrawal syndrome that can cause seizures, psychosis, and death. Drugs which lower the seizure threshold such as tramadol and amphetamine should be avoided during withdrawal.
Tolerance will develop to the sedative-hypnotic effects of carisoprodol after prolonged use. It is unknown exactly how long it takes for tolerance to reach baseline.
Although many psychoactive substances are safe to use on their own, they can quickly become dangerous or even life-threatening when combined with other substances. The following lists some known dangerous combinations, but may not include all of them. A combination that appears to be safe in low doses can still increase the risk of injury or death. Independent research should always be conducted to ensure that a combination of two or more substances is safe to consume. Some interactions listed have been sourced from Tripsit.
- Depressants (1,4-Butanediol, 2M2B, alcohol, benzodiazepines, barbiturates, GHB/GBL, methaqualone, opioids) - This combination potentiates the muscle relaxation, amnesia, sedation, and respiratory depression caused by one another. At higher doses, it can lead to a sudden, unexpected loss of consciousness along with a dangerous amount of depressed respiration. There is also an increased risk of suffocating on one's vomit while unconscious. If nausea or vomiting occurs before a loss of consciousness, users should attempt to fall asleep in the recovery position or have a friend move them into it.
- Stimulants - It can be dangerous to combine depressants with stimulants due to the risk of accidental excessive intoxication. Stimulants mask the sedative effect of depressants, which is the main factor most people use to gauge their level of intoxication. Once the stimulant effects wear off, the effects of the depressant will significantly increase, leading to intensified disinhibition, motor control loss, and dangerous black-out states. This combination can also potentially result in severe dehydration if one's fluid intake is not closely monitored. If choosing to combine these substances, one should strictly limit themselves to a pre-set schedule of dosing only a certain amount per hour until a maximum threshold has been reached.
- Dissociatives - This combination can unpredictably potentiate the amnesia, sedation, motor control loss and delusions that can be caused by each other. It may also result in a sudden loss of consciousness accompanied by a dangerous degree of respiratory depression. If nausea or vomiting occurs before consciousness is lost, users should attempt to fall asleep in the recovery position or have a friend move them into it.
In most jurisdictions, carisoprodol is considered a prescription-only and/or controlled drug.
- United States: In the United States, carisoprodol is a Schedule IV Controlled Substance. Therefore, it is prescription-only and anyone caught in possession of the substance with or without intent to distribute is punishable by law.
- Risks of Combining Depressants (Tripsit) | https://tripsit.me/combining-depressants/
- Barbiturate-Like Actions of the Propanediol Dicarbamates Felbamate and Meprobamate | http://jpet.aspetjournals.org/content/280/3/1383.long
- A purinergic component in the central actions of meprobamate. | https://www.ncbi.nlm.nih.gov/pubmed/6468504
- DEA Scheduled Drugs | https://www.deadiversion.usdoj.gov/schedules/orangebook/e_cs_sched.pdf