Editing Methadone (section)

=== Route of administration ===
The most common [[route of administration]] at a methadone clinic is in a [[racemic]] oral solution, though in Germany, only the ''R'' [[enantiomer]] (the [[levorotatory|L]] optical isomer) has traditionally been used, as it is responsible for most of the desired opioid effects.<ref name="EapI"/> The single-isomer form is becoming less common due to the higher production costs.

Methadone is available in traditional pills, [[sublingual]] tablets, and two different formulations designed for the person to drink. Drinkable forms include ready-to-dispense liquid (sold in the [[United States]] as Methadose), and Diskets (known on the street as "wafers" or "biscuits") tablets which are dispersible in water for oral administration, used similarly to [[Alka-Seltzer]]. The liquid form is the most common as it allows for smaller dose changes. Methadone is almost as effective when administered orally as by injection. Oral medication is usually preferable because it offers safety, and simplicity and represents a step away from injection-based drug abuse in those recovering from addiction. U.S. federal regulations require the oral form in addiction treatment programs.<ref name="ReferenceA">Code of Federal Regulations, Title 42, Sec 8.</ref> Injecting methadone pills can cause collapsed veins, bruising, swelling, and possibly other harmful effects. Methadone pills often contain talc that, when injected, produces a swarm of tiny solid particles in the blood, causing numerous minor blood clots.<ref>{{cite web |url=http://www.vistapharm.com/methadone_tablets.pdf |title=Methadone Hydrochloride Tablets, USP |publisher=VistaPharm |url-status=dead |archive-url=https://web.archive.org/web/20130511224428/http://www.vistapharm.com/methadone_tablets.pdf |archive-date=11 May 2013 }}</ref><ref>{{cite journal | vauthors = Murphy SB, Jackson WB, Pare JA | title = Talc retinopathy | journal = Canadian Journal of Ophthalmology. Journal Canadien d'Ophtalmologie | volume = 13 | issue = 3 | pages = 152–156 | date = July 1978 | pmid = 698886 }}</ref> These particles cannot be filtered out before injection, and will accumulate in the body over time, especially in the lungs and eyes, producing various complications such as [[pulmonary hypertension]], an irreversible and progressive disease.<ref>{{cite journal | vauthors = Hill AD, Toner ME, FitzGerald MX | title = Talc lung in a drug abuser | journal = Irish Journal of Medical Science | volume = 159 | issue = 5 | pages = 147–148 | date = May 1990 | pmid = 2397985 | doi = 10.1007/BF02937408 | s2cid = 41611298 }}</ref><ref>{{cite journal | vauthors = Cappola TP, Felker GM, Kao WH, Hare JM, Baughman KL, Kasper EK | title = Pulmonary hypertension and risk of death in cardiomyopathy: patients with myocarditis are at higher risk | journal = Circulation | volume = 105 | issue = 14 | pages = 1663–1668 | date = April 2002 | pmid = 11940544 | doi = 10.1161/01.CIR.0000013771.30198.82 | doi-access =  | title-link = doi | s2cid = 298931 }}</ref><ref>{{cite journal | vauthors = Humbert M | title = Improving survival in pulmonary arterial hypertension | journal = The European Respiratory Journal | volume = 25 | issue = 2 | pages = 218–220 | date = February 2005 | pmid = 15684283 | doi = 10.1183/09031936.05.00129604 | doi-access = free | title-link = doi }}</ref> The formulation sold under the brand name Methadose (flavored liquid suspension for oral dosing, commonly used for [[Methadone maintenance|maintenance purposes]]) should not be injected either.<ref>{{cite journal | vauthors = Lintzeris N, Lenné M, Ritter A | title = Methadone injecting in Australia: a tale of two cities | journal = Addiction | volume = 94 | issue = 8 | pages = 1175–1178 | date = August 1999 | pmid = 10615732 | doi = 10.1046/j.1360-0443.1999.94811757.x | doi-access = free }}</ref>

Information leaflets included in packs of UK methadone tablets state that the tablets are for oral use only and that use by any other route can cause serious harm. In addition to this warning, additives have now been included in the tablet formulation to make the use of them by the IV route more difficult.<ref>Dales pharmaceuticals patients information leaflet revision 09/10{{verify source|date=December 2013}}</ref>

Methadone is also available in ampoules with strength of 50mg/ml & 10mg/ml for IV/IM/SC use in the UK.<ref>{{cite web |title=BNF |url=https://bnf.nice.org.uk/drugs/methadone-hydrochloride/medicinal-forms/#solution-for-injection |website=NICE}}</ref> Prescribing the injectable formulation was more common in the 90s with prescribers reporting that up to 9-10% of all methadone prescription were for ampoules. This practice is much less common nowadays  <ref>{{cite journal | vauthors = Strang J, Sheridan J, Hunt C, Kerr B, Gerada C, Pringle M | title = The prescribing of methadone and other opioids to addicts: national survey of GPs in England and Wales | journal = The British Journal of General Practice | volume = 55 | issue = 515 | pages = 444–451 | date = June 2005 | pmid = 15970068 | pmc = 1472740 }}</ref>