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=== Also known as ===

Lyrica

=== Classification ===

Gabapentinoid
[[Category:Gabapentinoids]]
=== Overview ===

Pregabalin is a prescription only medicine used to treat epilepsy, neuropathic pain (which is the result of damage to nerve tissue which can produce a burning, shooting or scalding feeling) and anxiety.

A prescription only medicine can only be prescribed following a consultation with a doctor.

Pregabalin can produce feelings of relaxation, calmness and euphoria, like tranquillisers.

It can enhance the euphoric effects of other drugs, like opiates, and is likely to increase the risks when taken in this way <ref name="1a">'''Pregabalin''', 2017, http://www.talktofrank.com/drug/pregabalin</ref>.

=== What does it look like? ===

Pregabalin comes as white, yellow or orange tablets/capsules. They are normally swallowed, although powder from capsules may be snorted <ref name="2a">'''Pregabalin''', 2016, http://www.drugwise.org.uk/pregabalin/</ref>. Pregabalin is manufactured as either white, white/orange or orange capsules <ref name="1a"/>.

=== Street price ===

50p to £1 on the street <ref name="3a">'''Pregabalin''', 2017, http://www.kfx.org.uk/drug_facts/drug_facts_pregabalin.php</ref>.

=== How long do its effects last? ===

==== Onset of effects ====

* oral - 30 - 90 minutes <ref name="4a">'''Pregabalin''', 2017, http://psychonautwiki.org/wiki/Pregabalin</ref>.
* all [[ROA]]'s - 90 - 150 minutes <ref name="5a">'''Pregabalin''', 2016, http://drugs.tripsit.me/pregabalin</ref>.

==== Duration of effects ====

* oral - 6 - 14 hours <ref name="4a"/>.
* all [[ROA]]'s - 6 - 14 hours <ref name="5a"/>.

==== After-effects ====

* all [[ROA]]'s - 1 - 12 hours <ref name="5a"/>.

=== Pharmacology ===

==== Pharmacodynamics ====

The pharmacological action of pregabalin is mediated by binding to the α2δ-1 site of voltage-gated calcium channels <ref name="6a">Field, M. J. and Cox, P. J. and Stott, E. and Melrose, H. and Offord, J. and Su, T. Z. and Bramwell, S. and Corradini, L. and England, S. and Winks, J. and Kinloch, R. A. and Hendrich, J. and Dolphin, A. C. and Webb, T. and Williams, D., '''Identification of the α2-δ-1 subunit of voltage-dependent calcium channels as a molecular target for pain mediating the analgesic actions of pregabalin''', ''Proceedings of the National Academy of Sciences'', 2006, 103, 46, 17537-17542, https://doi.org/10.1073/pnas.0409066103, http://www.pnas.org/content/103/46/17537.abstract</ref>, <ref name="7a">Eroglu, Ç. and Allen, N. J. and Susman, M. W. and O'Rourke, N. A. and Park, C. Y. and Özkan, E. and Barres, B. A., '''Gabapentin Receptor α2δ-1 Is a Neuronal Thrombospondin Receptor Responsible for Excitatory CNS Synaptogenesis''', ''Cell'', 2009, 139, 2, 380-392, https://doi.org/10.1016/j.cell.2009.09.025, https://www.ncbi.nlm.nih.gov/pubmed/19818485</ref>. This site has also been referred to as the gabapentin receptor, as it is the target of the related substance gabapentin (also developed by Pfizer). Advantages to pregabalin over gabapentin include higher bioavailability and potency.

Although pregabalin is a chemical derivative of [[GABA]], it displays no activity at any [[GABA]] receptors, including GABAA, GABAB and the benzodiazepine site. Pregabalin, despite its [[GABA]] backbone, does not appear to alter [[GABA]] levels in the brain, so its pharmacological activity is presumed to be unrelated to [[GABA]] <ref name="8a">Taylor, C. P. and Angelotti, T. and Fauman, E., '''Pharmacology and mechanism of action of pregabalin: The calcium channel  α2–δ (alpha2-delta) subunit as a target for antiepileptic drug discovery''', ''Epilepsy Research'', 2007, 73, 2, 137-150, https://doi.org/10.1016/j.eplepsyres.2006.09.008, http://www.sciencedirect.com/science/article/pii/S0920121106003895</ref>. Instead, it is its binding to the α2δ-1 site of voltage-gated calcium channels which appears to be the source of its subjective effects. By binding to this site, Pregabalin reduces the release of several excitatory neurotransmitters, including glutamate, substance P, acetylcholine and norepinephrine.

One study has also shown that pregabalin promotes deep sleep, thus enhancing sleep quality. This may be substantial because reductions in slow-wave sleep have been associated with anxiety and fibromyalgia <ref name="9a">Hindmarch, I. and Dawson, J. and Stanley, N., '''A double-blind study in healthy volunteers to assess the effects on sleep of pregabalin compared with alprazolam and placebo''', ''Sleep'', 2005, 28, 2, 187-193, https://www.ncbi.nlm.nih.gov/pubmed/16171242</ref>. Also, an independent action of the gabapentin site on the neurogenesis of excitatory synapses has been discovered. The endogenous neurochemical thrombospondin also binds to this site and is important for the generation of new excitatory synapses. Gabapentin and pregabalin, having a high affinity for this site, block this action and result in lower levels of excitatory synapses in animal models <ref name="7a"/>, <ref name="4a"/>.

==== Pharmacokinetics ====

Pregabalin is rapidly absorbed when administered on an empty stomach, with peak plasma concentrations occurring within 1 to 1.5 hours. Pregabalin oral bioavailability is estimated to be greater than or equal to 90%. The rate of pregabalin absorption is decreased when given with food, resulting in delay of approximately 3 hours to reach peak plasma concentrations, with peak levels themselves, decreased by about 25% to 30% <ref name="10a">'''Pregabalin''', 2017, https://www.drugs.com/ppa/pregabalin.html</ref>. Administration with food, however, has no clinically significant effect on the extent of absorption <ref name="11a">'''Summary Of Product Characteristics''', 2016, http://web.archive.org/web/20160305012454/http//www.ema.europa.eu/docs/en_GB/document_library/EPAR_-_Product_Information/human/000546/WC500046602.pdf</ref>.

Pregabalin undergoes negligible metabolism in humans. In experiments using nuclear medicine techniques, it was revealed that approximately 98% of the radioactivity recovered in the urine was unchanged pregabalin. The primary metabolite is N-methyl pregabalin.

Pregabalin is eliminated from the systemic circulation primarily by renal excretion as unchanged substance. Renal clearance of pregabalin is 73 mL/minute <ref name="12a">'''Lyrica''', 2016, http://web.archive.org/web/20160305071130/http//dailymed.nlm.nih.gov/dailymed/archives/fdaDrugInfo.cfm?archiveid=41099</ref>.

==== Absorption ====

Pregabalin is well absorbed after oral administration. When an oral administration of pregabalin under fasting conditions is given, the pharmacokinetic parameters are as follows - [[tmax]] = 1.5 hours; time to steady state = 24 - 48 hours <ref name="13a">'''Pregabalin''', 2017, https://www.drugbank.ca/drugs/DB00230</ref>.

==== Bioavailability ====

Oral bioavailability = >90% (independent of dose) <ref name="13a"/>.

==== Half-life ====

6.3 hours <ref name="13a"/>.

==== Elimination ====

90% of the dose was recovered in the urine as the parent compound. The N-methylated derivative of pregabalin, the major metabolite was found in the urine and accounted for 0.9% of the dose <ref name="13a"/>.

==== Lethal dosage ====

Both rat and mouse oral acute [[LD50]] have been established to be greater than 5000mg/kg. Rat IV [[LD50]] was also determined to be greater than 300mg/kg <ref name="14a">'''Material Safety Data Sheet''', 2012, http://www.pfizer.com/files/products/material_safety_data/722.pdf</ref>, <ref name="4a"/>.

==== Toxicity ====

Most common adverse reactions (≥5% and twice [[placebo]]) are dizziness, somnolence, dry mouth, oedema, blurred vision, weight gain and thinking abnormal (primarily difficulty with concentration/attention) <ref name="13a"/>.

==== Tolerance ====

Tolerance will develop to the depressant effects within several days of continuous use. After cessation, the tolerance returns to baseline in 7 - 14 days. Withdrawal symptoms or rebound symptoms may occur after ceasing usage abruptly following a few weeks or longer of steady dosing and may necessitate a gradual dose reduction <ref name="4a"/>.

==== Mechanism of action ====

Pregabalin binds with high affinity to the alpha2-delta site (an auxiliary subunit of voltage-gated calcium channels) in [[central nervous system]] tissues. Although the mechanism of action of pregabalin is unknown, results with genetically modified mice and with compounds structurally related to pregabalin (such as [[gabapentin]]) suggest that binding to the alpha2-delta subunit may be involved in pregabalin's antinociceptive and antiseizure effects in animal models. [[in-vitro]], pregabalin reduces the calcium-dependent release of several neurotransmitters, possibly by modulation of calcium channel function. Studies also suggest that the descending noradrenergic and serotonergic pathways originating from the brainstem may be involved with the mechanism of pregabalin. Interestingly, although pregabalin is a structural derivative of inhibitory neurotransmitter [[GABA]], it does not bind directly to [[GABA]] or benzodiazepine receptors. The sodium channels, opiate receptors, and cyclooxygenase enzymes are not involved with the mechanism of pregabalin. It is also inactive at serotonin and dopamine receptors and does not inhibit dopamine, serotonin, or noradrenaline reuptake <ref name="13a"/>.

=== Mode of use ===

Pregabalin capsules are normally swallowed <ref name="1a"/>.

=== Effects ===

==== Common ====

Pregabalin can produce feelings of -

* euphoria,
* relaxation,
* calmness <ref name="1a"/>.

It can also enhance/increase the euphoric effects of other drugs, like opiates <ref name="1a"/>.

==== Uncommon ====

Less commonly, pregabalin can cause -

* [[hallucinations]],
* heart problems (including heart failure),
* depression,
* agitation,
* panic attacks <ref name="1a"/>.

==== Physical effects ====

* muscle relaxation,
* physical euphoria,
* motor control loss,
* pain relief,
* respiratory depression,
* sedation,
* seizure suppression,
* dizziness,
* muscle spasms <ref name="4a"/>.

==== Cognitive effects ====

* cognitive euphoria,
* dream potentiation,
* empathy, love, and sociability enhancement,
* increased libido,
* increased music appreciation,
* motivation enhancement,
* amnesia,
* anxiety suppression,
* decreased libido,
* disinhibition,
* information processing suppression,
* thought deceleration <ref name="4a"/>.

==== Visual effects ====

* colour enhancement,
* acuity suppression,
* internal hallucinations <ref name="4a"/>.

==== Auditory effects ====

* auditory distortion,
* auditory enhancement <ref name="4a"/>.

==== Side-effects ====

* constipation,
* vomiting,
* nausea,
* flatulence,
* poor muscle control,
* trouble sleeping,
* weight gain,
* visual disturbances like blurred vision <ref name="1a"/>.

=== Risks ===

Pregabalin can cause these risks, all of which can put you at risk of hurting yourself <ref name="1a"/>.

* dizziness,
* drowsiness,
* confusion <ref name="1a"/>.

=== Purity ===

It's likely that most of the pregabalin that is available on the black market has been either stolen from a hospital or pharmacy or stolen (possibly bought) from people who have been prescribed pregabalin.

They might have also been imported from abroad. You cannot normally be sure of the purity unless you are certain that the drug you have is a genuine pharmacy medicine <ref name="1a"/>.

=== Addiction ===

Pregabalin is moderately physically and psychologically addictive <ref name="4a"/>.

==== Can you get addicted ====

It is recommended that prescribed pregabalin use is not stopped abruptly as it may cause anxiety, insomnia, nausea, pain and sweating.

Substantial misuse of pregabalin has been reported. In view of this and in view of pregabalin known effects, it seems possible that dependence may develop in some regular users <ref name="1a"/>.

=== Withdrawal ===

The withdrawal effects of abrupt cessation of chronic usage include -

* anxiety,
* insomnia,
* sweating,
* muscle spasms,
* gastrointestinal problems,
* hot and cold flushes,
* nausea,
* flu-like feeling <ref name="4a"/>.

There exist reports of patients with history of both opioid and benzodiazepine abuse who considered pregabalin withdrawal to be worse than benzodiazepine or heroin withdrawal <ref name="15a">Nordmo, E. and Vorren, S., '''Lyrica - norske bivirkningsmeldinger om misbruk''', 2014, http://web.archive.org/web/20150910231010/http//www.relis.no/Bivirkninger/Nytt_om_bivirkninger/2014/Misbruk_avhengighet_og_seponeringsreaksjoner_ved_bruk_av_Lyrica_norske_bivirkningsmeldinger</ref>, <ref name="4a"/>.

=== Legality ===

Pregabalin is a prescription only medicine and can only be prescribed following a consultation with a doctor <ref name="1a"/>.

==== Did you know? ====

Like drinking and driving, driving while under the influence of drugs is illegal – with some drugs you can still be unfit to drive the day after using. You can get a heavy fine, be disqualified from driving or even go to prison <ref name="1a"/>.

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== References ==

<references />

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Pregabalin - Revision history

Sharon: /* References */

Sharon: Created page with "=== Also known as === Lyrica === Classification === Gabapentinoid Category:Gabapentinoids === Overview === Pregabalin is a prescription only medicine used to treat epi..."