Extended-release (or slow-release) formulations of morphine are those whose effect last substantially longer than bare
morphine
Morphine, formerly also called morphia, is an opiate that is found naturally in opium, a dark brown resin produced by drying the latex of opium poppies (''Papaver somniferum''). It is mainly used as an analgesic (pain medication). There are ...
, availing for, e.g., one administration per day. Conversion between
extended-release and immediate-release (or "regular") morphine is easier than conversion to or from an
equianalgesic dose of another opioid with different half-life, with less risk of altered
pharmacodynamics
Pharmacodynamics (PD) is the study of the biochemistry, biochemical and physiology, physiologic effects of drugs (especially pharmaceutical drugs). The effects can include those manifested within animals (including humans), microorganisms, or comb ...
.
Brand names
Brand names for this formulation of morphine include Avinza,
[ Kadian,][ MS Contin,] MST Continus, Morphagesic, Zomorph, Filnarine, MXL, Malfin, Contalgin, Dolcontin, and DepoDur.[ Last reviewed on 11/18/2015] MS Contin is a trademark
A trademark (also written trade mark or trade-mark) is a form of intellectual property that consists of a word, phrase, symbol, design, or a combination that identifies a Good (economics and accounting), product or Service (economics), service f ...
of Purdue Pharma
Purdue Pharma L.P., formerly the Purdue Frederick Company (1892–2019), was an American privately held pharmaceutical company founded by John Purdue Gray. It was sold to Arthur Sackler, Arthur, Mortimer Sackler, Mortimer, and Raymond Sackler in 1 ...
, and is available in the United States and Australia. In the UK, MS Contin is marketed by NAPP Pharmaceuticals as MST Continus. MS Contin is a DEA Schedule II substance in the United States, a Schedule 8 (controlled) drug in Australia and a Schedule 2 CD (Controlled Drug) in the UK.
Avinza is made by King Pharmaceuticals
King Pharmaceuticals, Inc. is a pharmaceutical company, a wholly owned subsidiary of Pfizer based in Bristol, Tennessee. Before being acquired by Pfizer, it was the world's 39th largest pharmaceutical company. On October 12, 2010, King was acqui ...
and Kadian is made by Actavis Pharmaceuticals. Unlike the MS Contin brand and its generic versions, Kadian and Avinza are designed to be 12- to 24-hour release, not 8- to 12-hour. So instead of 2–3 times a day dosing, it can be 1–2 times.
MST Continus and MXL are registered copyright
A copyright is a type of intellectual property that gives its owner the exclusive legal right to copy, distribute, adapt, display, and perform a creative work, usually for a limited time. The creative work may be in a literary, artistic, ...
and trademark of Napp Pharmaceuticals and are available in the UK. MXL is a 24-hour release formula designed to be taken once daily. It is available in doses between 30 mg and 200 mg in 30 mg intervals (equating to between 1.25 mg/hour and 8.33 mg/hour). MST Continus is a 12-hour release formula, therefore it is given 2 times per day. It is available in the following doses: 5 mg, 10 mg, 15 mg, 30 mg, 60 mg, 100 mg and 200 mg tablets (equating to between 0.416 mg/hour and 16.67 mg/hour).
Dosage comparison
For constant pain, the relieving effect of extended-release morphine given once (for Kadian) or twice (for MS Contin[) every 24 hours is roughly the same as multiple administrations of ''immediate release'' (or "regular") morphine.] Morphine sulfate pentahydrate (trade names including Dolcontin) has a higher molecular mass
The molecular mass () is the mass of a given molecule, often expressed in units of daltons (Da). Different molecules of the same compound may have different molecular masses because they contain different isotopes of an element. The derived quan ...
than morphine base, and therefore 10 mg morphine sulfate pentahydrate contains approximatively 7.5 mg of morphine free base.[ Translated from Swedish "Morfinsulfatpentahydrat 10 mg motsvarande morfin 7,5 mg"] Extended-release morphine can be administered together with "rescue doses" of immediate-release morphine pro re nata in case of breakthrough pain, each generally consisting of 5% to 15% of the 24-hour extended-release dosage.[
]
Structure
Some brands may have a pellet (spheroid) formulations (made by extrusion and spheronization) can be used for controlled release of the drug in the body whereas powder filled pellets generally cannot. The plastic spheres containing powder have micropores that open at varying pH levels, to maintain a mostly constant release during transit through the digestive tract
The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the Digestion, digestive system that leads from the mouth to the anus. The tract is the largest of the body's systems, after the cardiovascula ...
. The spheres themselves, the outer shells, pass undigested in most patients. Other brands are thought to use ethylcellulose
Ethyl cellulose (or ethylcellulose) is a derivative of cellulose in which some of the hydroxyl groups on the repeating glucose units are converted into ethyl ether groups. The number of ethyl groups can vary depending on the manufacturer.
It i ...
coatings to control drug release from pellets. Another use these medications have is that they can be given via NG tube, the pellets being very small. This makes them one of the few extended release oral medications that can be given by feeding tube.
Opioid replacement therapy
According to a Cochrane review
Cochrane is a British international charitable organisation formed to synthesize medical research findings to facilitate evidence-based choices about health interventions involving health professionals, patients and policy makers. It includes ...
in 2013, extended-release morphine as an opioid replacement therapy
Opioid agonist therapy (OAT) is a treatment in which prescribed opioid agonists are given to patients who live with opioid use disorder (OUD). In the case of methadone maintenance treatment (MMT), methadone is used to treat dependence on heroin ...
for people with heroin addiction or dependence confers a possible reduction of opioid use and with fewer depressive symptoms
Depression is a mental state of low mood and aversion to activity. It affects about 3.5% of the global population, or about 280 million people worldwide, as of 2020. Depression affects a person's thoughts, behavior, feelings, and sense o ...
but overall more adverse effects when compared to other forms of long-acting opioids. The length of time in treatment was not found to be significantly different.
References
External links
Advanced consumer information: morphine sulfate
{{Opioidergics
Analgesics
Opiates
Sulfates
Drugs developed by Pfizer