Methamphetamine: Difference between revisions

In addition to releasing potent amounts of monoamines, MA has a high lipid solubility which leads to a relatively fast transfer of the drug across the blood-brain barrier and a quick onset in comparison to other [[stimulant]]s.<ref name="Barr2006" /> All of this results in feelings of reward, euphoria, and stimulation as well as an unpleasant offset.

*'''[[Effect::Seizure]]''' - This is an uncommon effect but can happen in those predisposed to them, especially while in physically taxing conditions such as being dehydrated, fatigued or undernourished, or if misusing the substance for extended periods of time.

Unlike [[amphetamine]], methamphetamine is directly neurotoxic to [[dopamine]] neurons.<ref name="Nestler2009">{{cite book | vauthors=((Nestler, E. J.)), ((Hyman, S. E.)), ((Malenka, R. C.)) | date= 2009 | title=Molecular neuropharmacology: a foundation for clinical neuroscience | publisher=McGraw-Hill Medical | edition=2nd ed | isbn=9780071481274}}</ref> Moreover, methamphetamine abuse is associated with an increased risk of Parkinson's disease due to excessive pre-synaptic dopamine autoxidation, a mechanism of neurotoxicity.<ref name="Cruickshank2009">{{cite journal | vauthors=((Cruickshank, C. C.)), ((Dyer, K. R.)) | journal=Addiction (Abingdon, England) | title=A review of the clinical pharmacology of methamphetamine | volume=104 | issue=7 | pages=1085–1099 | date= July 2009 | issn=1360-0443 | doi=10.1111/j.1360-0443.2009.02564.x}}</ref><ref>{{cite journal | vauthors=((Thrash, B.)), ((Thiruchelvan, K.)), ((Ahuja, M.)), ((Suppiramaniam, V.)), ((Dhanasekaran, M.)) | journal=Pharmacological Reports | title=Methamphetamine-induced neurotoxicity: the road to Parkinson’s disease | volume=61 | issue=6 | pages=966–977 | date= November 2009 | url=https://linkinghub.elsevier.com/retrieve/pii/S1734114009701586 | issn=17341140 | doi=10.1016/S1734-1140(09)70158-6}}</ref><ref>{{cite journal | vauthors=((Sulzer, D.)), ((Zecca, L.)) | journal=Neurotoxicity Research | title=Intraneuronal dopamine-quinone synthesis: a review | volume=1 | issue=3 | pages=181–195 | date= February 2000 | issn=1029-8428 | doi=10.1007/BF03033289}}</ref><ref>{{cite journal | vauthors=((Miyazaki, I.)), ((Asanuma, M.)) | journal=Acta Medica Okayama | title=Dopaminergic neuron-specific oxidative stress caused by dopamine itself | volume=62 | issue=3 | pages=141–150 | date= June 2008 | issn=0386-300X | doi=10.18926/AMO/30942}}</ref> Similar to the neurotoxic effects on the dopamine system, methamphetamine can also result in neurotoxicity to [[serotonin]] [[neurons]].<ref name="Krasnova2009">{{cite journal | vauthors=((Krasnova, I. N.)), ((Cadet, J. L.)) | journal=Brain Research Reviews | title=Methamphetamine toxicity and messengers of death | volume=60 | issue=2 | pages=379–407 | date= May 2009 | issn=0165-0173 | doi=10.1016/j.brainresrev.2009.03.002}}</ref> It has been demonstrated that a high core temperature is correlated with an increase in the neurotoxic effects of methamphetamine.<ref>{{cite journal | vauthors=((Yuan, J.)), ((Hatzidimitriou, G.)), ((Suthar, P.)), ((Mueller, M.)), ((McCann, U.)), ((Ricaurte, G.)) | journal=The Journal of Pharmacology and Experimental Therapeutics | title=Relationship between temperature, dopaminergic neurotoxicity, and plasma drug concentrations in methamphetamine-treated squirrel monkeys | volume=316 | issue=3 | pages=1210–1218 | date= March 2006 | issn=0022-3565 | doi=10.1124/jpet.105.096503}}</ref> As a result of methamphetamine-induced neurotoxicity to dopamine neurons, chronic use may also lead to post acute withdrawals which persist beyond the withdrawal period for months, and even up to a year.<ref name="Cruickshank2009" />

In highly dependent [[amphetamine]] and methamphetamine abusers, "when chronic heavy users abruptly discontinue methamphetamine use, many report a time-limited withdrawal syndrome that occurs within 24 hours of their last dose".<ref name="Shoptaw2009">{{cite journal | vauthors=((Shoptaw, S. J.)), ((Kao, U.)), ((Heinzerling, K.)), ((Ling, W.)) | journal=The Cochrane Database of Systematic Reviews | title=Treatment for amphetamine withdrawal | issue=2 | pages=CD003021 | date=15 April 2009 | issn=1469-493X | doi=10.1002/14651858.CD003021.pub2}}</ref> Withdrawal symptoms in chronic, high-dose users are frequent, occurring in up to 87.6% of cases, and persist for three to four weeks with a marked "crash" phase occurring during the first week.<ref name="Shoptaw2009" /> Methamphetamine withdrawal symptoms can include anxiety, drug craving, dysphoric mood, fatigue, increased appetite, increased movement or decreased movement, lack of motivation, sleeplessness or sleepiness, and vivid or lucid dreams.<ref name="Shoptaw2009" /> Withdrawal symptoms are associated with the degree of dependence (i.e., the extent of abuse).<ref name="Shoptaw2009" /> The mental depression associated with methamphetamine withdrawal lasts longer and is more severe than that of [[cocaine]] withdrawal.<ref>{{cite journal | vauthors=((Winslow, B. T.)), ((Voorhees, K. I.)), ((Pehl, K. A.)) | journal=American Family Physician | title=Methamphetamine abuse | volume=76 | issue=8 | pages=1169–1174 | date=15 October 2007 | issn=0002-838X}}</ref>

Abuse of methamphetamine can result in a stimulant psychosis that may present with a variety of symptoms (e.g., [[Paranoia|paranoia]], [[External hallucinations|hallucinations]], [[delusions]]).<ref name="Shoptaw2009" /> A review on treatment for [[amphetamine]], [[dextroamphetamine]], and methamphetamine abuse-induced psychosis states that about 5–15% of users fail to recover completely.<ref name="Shoptaw2009" /><ref>{{cite book | vauthors=((Hofmann, F. G.)) | date= 1983 | title=A handbook on drug and alcohol abuse: the biomedical aspects | publisher=Oxford University Press | edition=2nd ed | isbn=9780195030563}}</ref> The same review asserts that, based upon at least one trial, [[antipsychotic]] medications effectively resolve the symptoms of acute amphetamine psychosis.<ref name="Shoptaw2009" /> Psychosis very rarely arises from therapeutic use.<ref>http://www.accessdata.fda.gov/drugsatfda_docs/label/2013/021303s026lbl.pdf</ref>

A methamphetamine overdose may result in a wide range of symptoms and is potentially fatal at heavy dosages.<ref>"Desoxyn Prescribing Information" | http://www.accessdata.fda.gov/drugsatfda_docs/label/2013/005378s028lbl.pdf</ref> A moderate overdose of methamphetamine may induce symptoms such as abnormal heart rhythm, confusion, dysuria, high or low blood pressure, hyperthermia, hyperreflexia, myalgia, severe agitation, tachypnea, tremor, urinary hesitancy, and urinary retention.<ref>{{cite book | veditors=((Goodman, L. S.)), ((Brunton, L. L.)), ((Chabner, B.)), ((Knollmann, B. C.)) | date= 2011 | title=Goodman & Gilman’s pharmacological basis of therapeutics | publisher=McGraw-Hill | edition=12th ed | isbn=9780071624428}}</ref> An extremely large overdose may produce symptoms such as adrenergic storm, methamphetamine psychosis, anuria, cardiogenic shock, cerebral hemorrhage, circulatory collapse, hyperpyrexia, pulmonary hypertension, renal failure, rhabdomyolysis, [[serotonin syndrome]], and a form of stereotypy ("tweaking"). A methamphetamine overdose will likely also result in mild brain damage due to dopaminergic and serotonergic neurotoxicity.<ref name="Nestler2009" /><ref name="Krasnova2009" /> Death from fatal methamphetamine poisoning is typically preceded by convulsions and coma.<ref>"Desoxyn Prescribing Information" | http://www.accessdata.fda.gov/drugsatfda_docs/label/2013/005378s028lbl.pdf</ref>