Non-euphorogenic----Naltrexone and Naloxone
Euphorogenic ----Methadone, Suboxone, Subutex, and Ultram (tramadol)
Naltrexone is a medication developed over 40 years ago by
Harold Blumberg
(US Patent No. 3,332,950) working for
the Endo Pharmaceutical Company in Delaware; the same Endo Pharmaceutical Company that makes Percocet. Like naloxone (Narcan),
which was developed by the same people four years earlier as the antidote for opiate overdoses, naltrexone is an opiate blocker.
While naloxone is an injectable medicine for use in an emergency, naltrexone was
developed as an oral medication for long term maintenance use in opiate addiction.
Early on there was some concern about hepatotoxicity (liver toxicity)
which has proven to be unfounded over the years.
Naltrexone, originally approved by the FDA and marketed as Trexan to treat opiate addiction, did not prove to be very
useful because patients were non-compliant: they didn't take the medication as prescribed. In 1994, the FDA approved the
use of naltrexone for the treatment of alcoholism when it was shown that it reduced cravings. It has been marketed as
Revia and is prescribed to be taken as a 50 mg tablet every day, or 100 mg (two tablets) on Monday and Wednesday and
150 mg (three tablets) on
Friday. Any opiates take during this time would be entirely ineffective.
About 10 years ago a naltrexone pellet was developed. It was noted that patients prescribed naltrexone after
Rapid Opiate Detoxifications (ROD) had a relapse rate of 33% in the month following
detoxification. The naltrexone pellets were noted to provide significant naltrexone blood levels for an extended period of time.
The technique for making the naltrexone pellets last for an
extended time was patented and the patent, US Patent No. 6,203,813 - Pharmaceutical delivery device and method of preparation
therefore - was licensed to make them available to patients in need of a
long acting naltrexone preparation, in accordance with FDA regulations on compounding.
A pre IND meeting was
requested. The meeting package was submitted and minutes
of the meeting were made available.
In June of 2006 Vivitol, another long-acting naltrexone preparation became available. It has been approved by the
FDA for use in the treatment of alcoholism, but is also used off-label to treat other conditions, most commonly,
opiate addiction. The Vivitrol injection is essentially a slurry of micro-pellets of a polymer material that have
been impregnated with naltrexone. The micro pellets have been described as being like chocolate chip cookies
where the cookies are made of the polymer and the chips are made of naltrexone.
The polymer is the same material that has been used in absorbable suture material. Its use in providing long acting
drug delivery was developed by Elie Nuwayser in Boston for which he received
U.S. Patent No. 7,041,320 - High drug loaded injectable microparticle compositions and methods of treating opioid drug dependence.
This polymer has also been used to deliver naltrexone over a long period of time (six months or more), by George O'Neil of Perth,
Australia. A similar preparation is reportedly available in China.
These preparations consist of 5 to 10 large pellets of the polymer impregnated with naltrexone.
