Also known as
Ultram, ultracet, ralivia, conzip, ryzolt, trammies, chill pills and ultras
Classification
Psychoactive substance, depressants
Overview
Tramadol, like other opiates, stimulates brain opioid receptorsnerve endings that sense changes in the body More but it also increases brain serotonin levels. It is a medicine used to treat moderate to severe pain. It is only available with a prescription from your doctor. Other opiates include codeine, methadone and heroin.
Although tramadol is not as strong as heroin, it shares many of the same effects and both are addictive 1.
Tramadol can –
- produce feelings of warmth and well-being, relaxation and sleepiness,
- cause fatiguea feeling of weariness, tiredness, or lack of energy. More, drowsiness, loss of appetite, nausea and retching, diarrhoeaWhere you frequently pass watery or loose faeces, and dizziness or fainting,
- worsen side-effects and risks when used with certain antidepressants that tend to increase serotonin levels 1.
What does it look like?
Tramadol is usually available as white pills, tablets or coloured capsules, although liquid forms are produced 1.
Source
This is a pharmaceutical drug which is sometimes diverted from manufacturers, pharmacies or GP’s prescriptions 2.
Street price
‘Street’ tramadol costs between £1 – £2.50 per pill/tablet/capsule 1.
Why take it?
Sought after effects
Undesired effects
- dizziness,
- nausea,
- constipationmeans that you're not passing stools regularly or you're unable to completely empty your bowels. More,
- dry mouth,
- headaches,
- sleepiness,
- sweating,
- tiredness,
- vomiting 2.
What are the different forms?
Tramadol is normally swallowed, but some people crush up the tablets and snort them 1.
Pharmacology
The R- and S- enantiomers of tramadol act on different receptorsnerve endings that sense changes in the body More in a complimentary manner. The R- enantiomer is a selective agonist of the mu receptorsnerve endings that sense changes in the body More and inhibits serotonin reuptake while the S- enantiomer inhibits noradrenaline reuptake. Tramadol acts as an opioid receptor agonist 5, 6, serotonin releasing agent, 7, 8, 9, norepinephrine reuptake inhibitor, 10, NMDA receptor antagonist, 11 5-HT2C receptor antagonist, 12 (α7)5 nicotinic acetylcholine receptor antagonist, TRPV1 receptor agonist, 13 and M1 and M3 muscarinic acetylcholine receptor antagonist 14, 15.
The euphoric effects of this compound stem from the way in which opioids bind to and activate the μ-opioid receptor. This occurs because opioids structurally mimic endogenousproduced within or caused by factors within the body. More endorphins'feel-good' chemicals produced by the body itself More which are naturally found within the body and also work upon the μ-opioid receptor set. The way in which opioids structurally mimic these natural endorphins'feel-good' chemicals produced by the body itself More results in their euphoriafeelings of joy and happiness, pain relief and anxiolyticDrugs that relieve medically-diagnosed anxiety. More effects. This is because endorphins'feel-good' chemicals produced by the body itself More are responsible for reducing pain, causing sleepiness, and feelings of pleasure. They can be released in response to pain, strenuous exercise, orgasm, or general excitement 3.
Bioavailability
- Oral – 68% – 72%,
- Rectal – 77% 3.
Toxicity
Tramadol has a low toxicityThis is when too much of something is taken over a short period of time More relative to dose. As with all opioids, long-term effects can vary but can include diminished libido, apathy and memory loss. It is also potentially lethal when mixed with depressants like alcohol or benzodiazepines and generally has a wider range of substances which it is dangerous to combine with in comparison to other opioids. It should not be taken during benzodiazepine withdrawal as this can potentially cause seizuresthe outward effect can vary from uncontrolled jerking movement (tonic-clonic seizure) to as subtle as a momentary loss of awareness More 3.
Tolerance
As with other opioids, the chronic use of tramadol can be considered moderately addictive with a high potential for abuse and is capable of causing psychological dependence among certain users. When addiction has developed, cravings and withdrawal symptoms may occur if a person suddenly stops their usage.
Tolerancethis is the process by which the receptors in your brain become habituated to the action of a drug. When tolerance is reached, more of the drug is required to achieve the same effect. With benzodiazepines, and probably with many other classes of drugs as well, tolerance is virtually always associated with some degree of physical dependence. If you find that you are experiencing tolerance, this is a clear warning sign that you may have formed a dependence. More to many of the effects of tramadol develops with prolonged and repeated use. The rate at which this occurs develops at different rates for different effects, with tolerancethis is the process by which the receptors in your brain become habituated to the action of a drug. When tolerance is reached, more of the drug is required to achieve the same effect. With benzodiazepines, and probably with many other classes of drugs as well, tolerance is virtually always associated with some degree of physical dependence. If you find that you are experiencing tolerance, this is a clear warning sign that you may have formed a dependence. More to the constipation-inducing effects developing particularly slowly for instance. This results in users having to administer increasingly large doses to achieve the same effects. After that, it takes about 3 – 7 days for the tolerancethis is the process by which the receptors in your brain become habituated to the action of a drug. When tolerance is reached, more of the drug is required to achieve the same effect. With benzodiazepines, and probably with many other classes of drugs as well, tolerance is virtually always associated with some degree of physical dependence. If you find that you are experiencing tolerance, this is a clear warning sign that you may have formed a dependence. More to be reduced to half and 1 – 2 weeks to be back at baseline (in the absence of further consumption). Tramadol presents cross-tolerance with all other opioids, meaning that after the consumption of tramadol all opioids will have a reduced effect 3.
Mode of use
Tablets and capsules are swallowed orally 2.
Signs of usage
- pinpointthe pupils are very small. More pupils,
- changes in appetite,
- nausea or vomiting,
- drowsiness,
- seizuresthe outward effect can vary from uncontrolled jerking movement (tonic-clonic seizure) to as subtle as a momentary loss of awareness More (without a history of epilepsy),
- slurred speech,
- headaches,
- impaired coordination 16.
Another potentially dangerous symptom of tramadol abuse is serotonin syndrome, which can be life-threatening if left untreated. It occurs when too much serotonin, a chemical that relays signals in the brain, is produced or remains in the brain. Serotonin syndrome most commonly occurs in patients who take tramadol and antidepressants at the same time 16.
Effects
Tramadol is an opiate. Although it is weaker than heroin and methadone, it still causes all the typical opiate effects, alongside some effects due to increases in serotonin activity 1. The effects include –
- feelings of warmth and well-being, relaxation and sleepiness 1.
Common effects
- fatiguea feeling of weariness, tiredness, or lack of energy. More,
- drowsiness,
- nausea,
- retching,
- constipationmeans that you're not passing stools regularly or you're unable to completely empty your bowels. More,
- confusiontrouble focusing, slow or disorganised thinking, poor short-term memory, unsure of time or place, or having difficulty following a conversation 1.
Less often effects
- diarrhoeaWhere you frequently pass watery or loose faeces,
- dizziness,
- fainting,
- excessive sweating,
- itching,
- raised blood pressure,
- tightness in the airways,
- muscle weakness,
- sensory disturbances,
- hallucinationswhere someone sees, hears, smells, tastes or feels things that don't exist outside of their mind,
- fits,
- blood disorders 1.
Physical effects
- physical euphoriaan intense feeling of pleasure and well-being More,
- pupil constriction,
- stimulationcan be defined as any changes in a person's energy levels which are interpreted as stimulating and encouraging when it comes to movement and physical activities such as running, walking, cleaning, socializing, dancing, and climbing More,
- appetite suppression,
- cough suppression,
- orgasm suppression,
- pain relief,
- sedationthe state of being relaxed or sleepy because of a drug More,
- constipationmeans that you're not passing stools regularly or you're unable to completely empty your bowels. More,
- difficulty urinating,
- itchiness,
- nausea 3.
Cognitive effects
- cognitive euphoriastate of intense well-being, happiness, and excitement More,
- compulsive redosing,
- dream potentiationcan be described as a cognitive component which increases the intensity, vividness and frequency of sleeping dream states. This effect also creates higher detail and definition within dreams alongside of an increase in the likelihood of one's dreams becoming lucid. More,
- thought acceleration,
- anxiety suppression,
- decreased libido 3.
Positive
Neutral
- itching 4.
Negative
Some users may experience –
- nausea,
- constipationmeans that you're not passing stools regularly or you're unable to completely empty your bowels. More,
- CNSthe Central Nervous System, upon which certain drugs act depression,
- drowsiness,
- hot/cold flashes,
- dizziness,
- vomiting,
- urinary retentiondifficulty urinating. More 4.
High doses
In high doses, overdoses, or in patients not tolerant to opiates, tramadol can cause –
- shallow breathing,
- bradycardiawhen the heart beats very slowly,
- cold-clammy skin,
- apnoeaSuspension of breathing. During apnoea, there is no movement of the muscles of inhalation, and the volume of the lungs initially remains unchanged. More,
- hypotensionlow blood pressure More,
- miosisa medical condition characterised by contraction of the pupil for reasons other than increased light levels. More,
- circulatory collapse,
- respiratory arrestRespiratory arrest is caused by airway obstruction, decreased respiratory drive, or respiratory muscle weakness. More,
- death 4.
Side-effects
- nausea,
- vomiting,
- constipationmeans that you're not passing stools regularly or you're unable to completely empty your bowels. More,
- lightheadedness or dizziness,
- drowsiness,
- headache,
- loss of appetite,
- dry mouth 17.
Overdose
- sleepiness,
- unconsciousness,
- coma,
- seizuresthe outward effect can vary from uncontrolled jerking movement (tonic-clonic seizure) to as subtle as a momentary loss of awareness More,
- respiratory depressionslowing the drive and effectiveness of breathing More,
- abnormally low blood pressure,
- slow heart rate,
- sweating or clammy skin,
- weak muscles,
- pinpointthe pupils are very small. More pupils 16,
- irregular heart rhythm,
- vomiting,
- hyperthermiaThis is a condition in which the body's temperature is higher than normal More,
- muscle rigidity,
- muscle pain,
- limp or weakened body,
- cyanosisbluish tinge to fingers and lips, caused by inadequate blood supply 18.
Side-effects of snorting tramadol
- insomniadifficulty in going to sleep or in getting enough sleep,
- muscle tension,
- headache,
- shakiness,
- feeling nervous or worried,
- shifting moods/irritability,
- sexual dysfunction,
- problems with breathing,
- difficulty swallowing,
- hoarseness,
- hallucinationswhere someone sees, hears, smells, tastes or feels things that don't exist outside of their mind,
- dry mouth,
- heartburn,
- poor appetite,
- nausea and vomiting,
- constipationmeans that you're not passing stools regularly or you're unable to completely empty your bowels. More,
- drowsiness,
- loss of consciousness,
- an inability to smell,
- nosebleeds,
- runny nose,
- difficulty swallowing 18.
Risks
Although tramadol is not as potent as the strongest opiates like heroin, it still acts as an opiate, and also has additional risks due to its actions on serotonin levels –
- if you have epilepsy or are taking certain antidepressants you should definitely only take tramadol with clear medical advice because of the known risks,
- tramadol can depress breathing and may be risky in asthma and chronic obstructive pulmonary disease,
- tramadol use has been linked with serotonin syndrome. This is a potentially life threatening condition where the serotonin receptorsnerve endings that sense changes in the body More are over stimulated, which can lead to high fever, rapid pulse, shivering, sweating, trembling, muscle twitches, agitation and confusiontrouble focusing, slow or disorganised thinking, poor short-term memory, unsure of time or place, or having difficulty following a conversation,
- pregnant women should not use tramadol as it can be toxiccapable of causing injury or death to the developing foetus 1.
Long-term
- tolerancethis is the process by which the receptors in your brain become habituated to the action of a drug. When tolerance is reached, more of the drug is required to achieve the same effect. With benzodiazepines, and probably with many other classes of drugs as well, tolerance is virtually always associated with some degree of physical dependence. If you find that you are experiencing tolerance, this is a clear warning sign that you may have formed a dependence. More,
- physical dependence,
- psychological dependence,
- withdrawal symptoms,
- increased risk of adverse effects 2.
Purity
Only tramadol tablets that were dispensed from a pharmacy directly to you are reliably pure and have the strength indicated. It is important to think quite hard about any ‘medications’ you take from an uncertain source 1.
Addiction
Can you get addicted?
Tramadol is addictive.
Over time, using tramadol produces ‘cravings’ and a psychological desire to keep on using.
Tolerancethis is the process by which the receptors in your brain become habituated to the action of a drug. When tolerance is reached, more of the drug is required to achieve the same effect. With benzodiazepines, and probably with many other classes of drugs as well, tolerance is virtually always associated with some degree of physical dependence. If you find that you are experiencing tolerance, this is a clear warning sign that you may have formed a dependence. More can also build, so that users have to take more just to get the same effects or to avoid an unpleasant withdrawal 3.
Interactions
- depressants (1,4-Butanediol, 2m2b, alcohol, barbiturates, benzodiazepines, GHB/GBL, methaqualone) – This combination can result in dangerous or even fatal levels of respiratory depressionslowing the drive and effectiveness of breathing More. These substances potentiate the muscle relaxation, sedationthe state of being relaxed or sleepy because of a drug More and amnesiainability to remember 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 attempt to fall asleep in the recovery position or have a friend move them into it.
- dissociatives – This combination can result in an increased risk of vomiting during unconsciousness and death from the resulting suffocation. If this occurs, users should attempt to fall asleep in the recovery position or have a friend move them into it.
- stimulants – It is dangerous to combine tramadol, a depressant, with stimulants due to the risk of excessive intoxication. Stimulants decrease the sedativeOne of a diverse group of drugs manufactured for medical purposes to relax the central nervous system. More effect of tramadol, which is the main factor most people consider when determining their level of intoxication. Once the stimulanta drug that acts on the Central Nervous System, increasing some rates of function such as heart-rate wears off, the effects of tramadol will be significantly increased, leading to intensified disinhibition as well as other effects. If combined, one should strictly limit themselves to only taking a certain amount of tramadol.
- psychedelics – Tramadol is well known to lower seizure threshold and psychedelics also cause occasional seizuresthe outward effect can vary from uncontrolled jerking movement (tonic-clonic seizure) to as subtle as a momentary loss of awareness More 3.
Dangerous
- αMT,
- Ketamine,
- MXE,
- DXM,
- PCP,
- Amphetamines – Tramadol and stimulants both increase the risk of seizuresthe outward effect can vary from uncontrolled jerking movement (tonic-clonic seizure) to as subtle as a momentary loss of awareness More.
- MDMA – Tramadol and stimulants both increase the risk of seizuresthe outward effect can vary from uncontrolled jerking movement (tonic-clonic seizure) to as subtle as a momentary loss of awareness More.
- Cocaine – Tramadol and stimulants both increase the risk of seizuresthe outward effect can vary from uncontrolled jerking movement (tonic-clonic seizure) to as subtle as a momentary loss of awareness More.
- Alcohol – Heavy CNSthe Central Nervous System, upon which certain drugs act depressants, risk of seizuresthe outward effect can vary from uncontrolled jerking movement (tonic-clonic seizure) to as subtle as a momentary loss of awareness More. Both substances potentiate the ataxialoss of motor coordination More and sedationthe state of being relaxed or sleepy because of a drug More caused by the other and can lead to unexpected loss of consciousness at high doses. Place affected patients in the recovery position to prevent vomit aspirationvomit being inhaled into the lungs, a potentially life-threatening condition More from excess. Memory blackouts are likely.
- GHB/GBL – The sedativeOne of a diverse group of drugs manufactured for medical purposes to relax the central nervous system. More effects of this combination can lead to dangerous respiratory depressionslowing the drive and effectiveness of breathing More.
- Opioids – Concomitant use of tramadol increases the seizure risk in patients taking other opioids. These agents are often individually epileptogenic and may have additive effects on seizure threshold during coadministration. Central nervous system- and/or respiratory-depressant effects may be additively or synergisticallyThe effect arising between two or more agents, entities, factors, or substances that produce an effect greater than the sum of their individual effects. More present.
- Benzodiazepines – Central nervous system- and/or respiratory-depressant effects may be additively or synergisticallyThe effect arising between two or more agents, entities, factors, or substances that produce an effect greater than the sum of their individual effects. More present. Vomit aspirationvomit being inhaled into the lungs, a potentially life-threatening condition More a risk when passed out, lay down in recovery position if ingested.
- MAOIsMAOIs may be used to treat the symptoms of depression. More,
- SSRIs 3.
Unsafe
- Mushrooms – Tramadol is well known to lower seizure threshold and psychedelics also cause occasional seizuresthe outward effect can vary from uncontrolled jerking movement (tonic-clonic seizure) to as subtle as a momentary loss of awareness More.
- LSD – Tramadol is well known to lower seizure threshold and psychedelics also cause occasional seizuresthe outward effect can vary from uncontrolled jerking movement (tonic-clonic seizure) to as subtle as a momentary loss of awareness More.
- DMT – Tramadol is well known to lower seizure threshold and psychedelics also cause occasional seizuresthe outward effect can vary from uncontrolled jerking movement (tonic-clonic seizure) to as subtle as a momentary loss of awareness More.
- Mescaline – This combination can cause seizuresthe outward effect can vary from uncontrolled jerking movement (tonic-clonic seizure) to as subtle as a momentary loss of awareness More due to the lowering of the threshold by tramadol and the potential of mescaline to cause seizuresthe outward effect can vary from uncontrolled jerking movement (tonic-clonic seizure) to as subtle as a momentary loss of awareness More.
- DOx – Tramadol is well known to lower seizure threshold and psychedelics also cause occasional seizuresthe outward effect can vary from uncontrolled jerking movement (tonic-clonic seizure) to as subtle as a momentary loss of awareness More.
- NBOMes – Tramadol is well known to lower seizure threshold and NBOMes have also shown a tendency to cause severe seizuresthe outward effect can vary from uncontrolled jerking movement (tonic-clonic seizure) to as subtle as a momentary loss of awareness More.
- 2C-x – Tramadol is well known to lower seizure threshold and psychedelics raise the risk of seizuresthe outward effect can vary from uncontrolled jerking movement (tonic-clonic seizure) to as subtle as a momentary loss of awareness More.
- 2C-T-x,
- 5-MeO-xxT 3.
Caution
- Nitrous oxide – Both substances potentiate the ataxialoss of motor coordination More and sedationthe state of being relaxed or sleepy because of a drug More caused by the other and can lead to unexpected loss of consciousness at high doses. While unconscious, vomit aspirationvomit being inhaled into the lungs, a potentially life-threatening condition More is a risk if not placed in the recovery position. Memory blackouts are likely 3.
Serotonin syndrome risk
Combinations in the list below may increase the amount of neurotransmitters such as serotonin and dopamine to dangerous or even fatal levels 3.
- MAOIsMAOIs may be used to treat the symptoms of depression. More such as syrian rue, banisteriopsis caapi, 2C-T-2, 2C-T-7, αMT, and some antidepressants,
- Serotonin releasers such as MDMA, 4-FA, MDAI and αMT,
- Selective serotonin re-uptake inhibitors (SSRIs),
- Serotonin-norepinephrine reuptake inhibitors (SNRIs),
- 5-HTP 3.
See Serotonin syndrome for more information.
Withdrawal
Symptoms include –
- nervous tremors,
- anxiety,
- yawning,
- sweating,
- runny nose,
- sleep disturbance,
- nausea,
- diarrhoeaWhere you frequently pass watery or loose faeces,
- goose-bumps,
- restlessness,
- abdominal cramps,
- muscle spasms 1,
- agitation,
- depression,
- cravings,
- nausea and vomiting,
- headaches,
- confusiontrouble focusing, slow or disorganised thinking, poor short-term memory, unsure of time or place, or having difficulty following a conversation,
- loss of appetite,
- blurred vision,
- insomniadifficulty in going to sleep or in getting enough sleep,
- mood swings,
- irritability,
- tingling sensations,
- nightmares,
- dizziness 16.
Timeline
- days 1 – 3 – onset of general withdrawal symptoms, including feelings of pins and needles, sweating, nervousness, nausea, anxiety, palpitations, insomniadifficulty in going to sleep or in getting enough sleep and drug cravings.
- days 4 – 7 – drug cravings persist, along with insomniadifficulty in going to sleep or in getting enough sleep, disorientation and confusiontrouble focusing, slow or disorganised thinking, poor short-term memory, unsure of time or place, or having difficulty following a conversation, and blurred vision.
- days 8 – 14 – symptoms should be fairly mild by this point. Depression, anxiety, and irrational thoughts may persist 16.
Legality
Tramadol is a class C drug and is only available with a prescription from a doctor or other healthcare professional that is qualified to prescribe. As a class C drug, it is illegal for anyone else to supply tramadol, to have it or to give it away, even to friends 1.
What if you’re caught?
- If the Police arrest you in possession of tramadol unlawfully, they’ll always take some action. This could be a formal caution or arrest and possible conviction.
- Having tramadol that is not prescribed for you for your own use (called illegal possession) could result in up to two years in prison and/or an unlimited fine. While selling or giving tramadol away for free, even to friends (called supplying) could result in up to fourteen years in prison and/or an unlimited fine.
- A conviction for a drug-related offence could have a serious impact. It could make it harder, even impossible, to visit certain countries- for example the United States – and limit the types of jobs you can apply for 1.
Did you know?
- Allowing other people to supply drugs in your house or any other premises is illegal. If the police catch people supplying illegal drugs in a club they can potentially prosecute the landlord, club owner or any person concerned in the management of the premises.
- Like drinking and driving, driving when high is illegal – and you can still be unfit to drive the day after using tramadol. You can get a heavy fine, be disqualified from driving or even go to prison 1.
Mixing with other drugs
Harm reduction
- do not drive or operate machinery while under the influence of tramadol,
- alcohol and many other drugs are extremely dangerous to combine with tramadol,
- mainly, do not combine with benzos, other opiates, or other serotogenic drugs,
- tramadol effects serotonin levels in the brain. For this reason it is recommended to taper on and taper off use over an extended time period 4.
Seizure Risk
We cannot stress this enough – if you have a history of seizuresthe outward effect can vary from uncontrolled jerking movement (tonic-clonic seizure) to as subtle as a momentary loss of awareness More, we strongly urge you to stay away from tramadol as a recreational substance. By itself, it can decrease the seizure threshold. When combined with SSRIs, tricyclic antidepressants, or in patients with epilepsy, the seizure threshold is further decreased. Seizuresthe outward effect can vary from uncontrolled jerking movement (tonic-clonic seizure) to as subtle as a momentary loss of awareness More have been reported in humans receiving excessive single oral doses (700 mg) or large intravenous doses (300 mg). However, there have been several rare cases of people having grand-mal seizuresthe outward effect can vary from uncontrolled jerking movement (tonic-clonic seizure) to as subtle as a momentary loss of awareness More at doses as low as 100 – 400 mg orally 4.
Footnotes:
Tramadol, 2017, http://www.talktofrank.com/drug/tramadol
Tramadol, 2014, http://www.dan247.org.uk/Drug_Tramadol.asp
Tramadol, 2017, https://psychonautwiki.org/wiki/Tramadol
Tramadol, 2017, https://wiki.tripsit.me/wiki/Tramadol
Hennies, H. H. and Friderichs, E. and Schneider, J., Receptor binding, analgesicpain relieving and antitussivea cough suppression medication. More potency of tramadol and other selected opioids, Arzneimittel-Forschung, 1988, 38, 7, 877-880, https://www.ncbi.nlm.nih.gov/pubmed/2849950
Frink, M. C. and Hennies, H. H. and Englberger, W. and Haurand, M. and Wilffert, B., Influence of tramadol on neurotransmitter systems of the rat brain, Arzneimittel-Forschung, 1996, 46, 11, 1029-1036, http://www.ncbi.nlm.nih.gov/pubmed/8955860
Gobbi, M. and Moia, M. and Pirona, L. and Ceglia, I. and Reyes-Parada, M. and Scorza, C. and Mennini, T., p-Methylthioamphetamine and 1-(m-chlorophenyl)piperazine, two non-neurotoxic 5-HT releasers in vivo, differ from neurotoxic amphetamine derivatives in their mode of action at 5-HT nerve endings in vitro, Journal of Neurochemistry, 2002, 82, 6, 1435-1443, http://dx.doi.org/10.1046/j.1471-4159.2002.01073.x, http://onlinelibrary.wiley.com/doi/10.1046/j.1471-4159.2002.01073.x/abstract
Driessen, B. and Reimann, W., Interaction of the central analgesicpain relieving, tramadol, with the uptake and release of 5-hydroxytryptamine in the rat brain in vitro, British Journal of Pharmacology, 1992, 105, 1, 147-151, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1908625/
Bamigbade, A. T. and Davidson, C. and Langford, R. M. and Stamford, J. A., Actions of tramadol, its enantiomers and principal metabolite, O-desmethyltramadol, on serotonin (5-HT) efflux and uptake in the rat dorsal raphe nucleus, British Journal of Anaesthesiathe state in which someone does not feel pain, usually because of drugs they have been given. More, 1997, 79, 3, 352-356, https://doi.org/10.1093/bja/79.3.352, https://academic.oup.com/bja/article/79/3/352/386035/Actions-of-tramadol-its-enantiomers-and-principal
Frink, M. C. and Hennies, H. H. and Englberger, W. and Haurand, M. and Wilffert, B., Influence of tramadol on neurotransmitter systems of the rat brain, Arzneimittel-Forschung, 1996, 46, 11, 1029-1036, https://www.ncbi.nlm.nih.gov/pubmed/8955860
Hara, K. and Minami, K. and Sata, T., The Effects of Tramadol and Its Metabolite on Glycine, -Aminobutyric AcidA, and N-Methyl-d-Aspartate Receptorsnerve endings that sense changes in the body More Expressed in Xenopus Oocytes, Anesthesia & Analgesiadecreased pain awareness. More, 2005, 100, 5, 1400-1405, https://doi.org/10.1213/01.ANE.0000150961.24747.98, http://journals.lww.com/anesthesia-analgesia/pages/articleviewer.aspx?year=2005&issue=05000&article=00037&type=abstract
Ogata, J. and Minami, K. and Uezono, Y. and Okamoto, T. and Shiraishi, M. and Shigematsu, A. and Ueta, Y., The Inhibitory Effects of Tramadol on 5-Hydroxytryptamine Type 2C Receptorsnerve endings that sense changes in the body More Expressed in Xenopus Oocytes, Anesthesia & Analgesiadecreased pain awareness. More, 2004, 98, 5, 1401-1406, https://doi.org/10.1213/01.ANE.0000108963.77623.A4, http://journals.lww.com/anesthesia-analgesia/pages/articleviewer.aspx?year=2004&issue=05000&article=00038&type=abstract
Marincsák, R. and Tóth, B. I. and Czifra, G. and Szabó, T. and Kovács, L. and Bíró, T., The analgesicpain relieving drug, tramadol, acts as an agonist of the transient receptor potential vanilloid-1, Anesthesia & Analgesiadecreased pain awareness. More, 2008, 106, 6, 1890-1896, https://doi.org/10.1213/ane.0b013e318172fefc, https://www.ncbi.nlm.nih.gov/pubmed/18499628
Shiraishi, M. and Minami, K. and Uezono, Y. and Yanagihara, N. and Shigematsu, A., Inhibition by tramadol of muscarinic receptor-induced responses in cultured adrenal medullary cells and in Xenopus laevis oocytes expressing cloned M1 receptorsnerve endings that sense changes in the body More, Journal of Pharmacology and Experimental Therapeutics, 2001, 299, 1, 255-260, https://www.ncbi.nlm.nih.gov/pubmed/11561087
Shiga, Y. and Minami, K. and Shiraishi, M. and Uezono, Y. and Murasaki, O. and Kaibara, M. and Shigematsu, A., The Inhibitory Effects of Tramadol on Muscarinic Receptor-Induced Responses in Xenopus Oocytes Expressing Cloned M3 Receptorsnerve endings that sense changes in the body More, Anesthesia & Analgesiadecreased pain awareness. More, 2002, 96, 5, 1269-1273, https://doi.org/10.1097/00000539-200211000-00031, http://journals.lww.com/anesthesia-analgesia/pages/articleviewer.aspx?year=2002&issue=11000&article=00031&type=abstract
Tramadol Symptoms and Warning Signs, 2017, https://www.addictioncenter.com/painkillers/tramadol/symptoms-signs/
Tramadol Abuse, 2017, http://drugabuse.com/library/tramadol-abuse/
Tramadol, 2017, http://drugabuse.com/?s=tramadol