Oxytrex
Encyclopedia
Oxytrex is an investigational drug currently in clinical trials. It combines the well known opioid
agonist
oxycodone
in the treatment of pain with an ultra-low dose of naltrexone
, an opioid antagonist
. Naltrexone
can have markedly different pharmacokinetics
at ultra-low doses which may include, the attenuation of a pre-established opioid tolerance, the prevention of tolerance from the oxycodone in the formulation
, and the possible amplification of oxycodone. It is being developed by Pain Therapeutics, Inc. for the treatment of severe chronic pain
.
A phase III clinical trial has shown that the combination of ULD (ultra-low dose) naltrexone with oxycodone has been nearly as effective in providing pain relief while causing less physical dependence than oxycodone alone. The trial has been criticized for its confounding and limiting factors which include the huge dropout rate (54%), lack of demographic stratification
of pain intensity amongst the study arms, and that patients received varying amounts of oxycodone which would influence their overall dependence. The lack of an on-board break-through-pain agent also hurts their external validity and likely contributed to their high dropout rate.
with Oxytrex than with oxycodone alone. Further study is needed. Less physical dependence
has been shown with the addition of the ULD naltrexone. If tolerance is delayed, the need to self-medicate may decrease leading to less abuse
of this opioid.
Opioid
An opioid is a psychoactive chemical that works by binding to opioid receptors, which are found principally in the central and peripheral nervous system and the gastrointestinal tract...
agonist
Agonist
An agonist is a chemical that binds to a receptor of a cell and triggers a response by that cell. Agonists often mimic the action of a naturally occurring substance...
oxycodone
Oxycodone
Oxycodone is an opioid analgesic medication synthesized from opium-derived thebaine. It was developed in 1916 in Germany, as one of several new semi-synthetic opioids in an attempt to improve on the existing opioids: morphine, diacetylmorphine , and codeine.Oxycodone oral medications are generally...
in the treatment of pain with an ultra-low dose of naltrexone
Naltrexone
Naltrexone is an opioid receptor antagonist used primarily in the management of alcohol dependence and opioid dependence. It is marketed in generic form as its hydrochloride salt, naltrexone hydrochloride, and marketed under the trade names Revia and Depade...
, an opioid antagonist
Opioid antagonist
An opioid antagonist is a receptor antagonist that acts on opioid receptors.Naloxone and naltrexone are commonly used opioid antagonist drugs which are competitive antagonists that bind to the opioid receptors with higher affinity than agonists but do not activate the receptors...
. Naltrexone
Naltrexone
Naltrexone is an opioid receptor antagonist used primarily in the management of alcohol dependence and opioid dependence. It is marketed in generic form as its hydrochloride salt, naltrexone hydrochloride, and marketed under the trade names Revia and Depade...
can have markedly different pharmacokinetics
Pharmacokinetics
Pharmacokinetics, sometimes abbreviated as PK, is a branch of pharmacology dedicated to the determination of the fate of substances administered externally to a living organism...
at ultra-low doses which may include, the attenuation of a pre-established opioid tolerance, the prevention of tolerance from the oxycodone in the formulation
Formulation
Formulation may refer to:* Clinical formulation* Formulations * Formulation science* Pharmaceutical formulation:** Galenic formulation* Pesticide formulation...
, and the possible amplification of oxycodone. It is being developed by Pain Therapeutics, Inc. for the treatment of severe chronic pain
Chronic pain
Chronic pain has several different meanings in medicine. Traditionally, the distinction between acute and chronic pain has relied upon an arbitrary interval of time from onset; the two most commonly used markers being 3 months and 6 months since the initiation of pain, though some theorists and...
.
A phase III clinical trial has shown that the combination of ULD (ultra-low dose) naltrexone with oxycodone has been nearly as effective in providing pain relief while causing less physical dependence than oxycodone alone. The trial has been criticized for its confounding and limiting factors which include the huge dropout rate (54%), lack of demographic stratification
Social stratification
In sociology the social stratification is a concept of class, involving the "classification of persons into groups based on shared socio-economic conditions ... a relational set of inequalities with economic, social, political and ideological dimensions."...
of pain intensity amongst the study arms, and that patients received varying amounts of oxycodone which would influence their overall dependence. The lack of an on-board break-through-pain agent also hurts their external validity and likely contributed to their high dropout rate.
Abuse Deterrence
Preclinical data may speculate, but there is no evidence that humans experience less euphoriaEuphoria
Euphoria is an emotional and mental state defined as a sense of great elation and well being.Euphoria may also refer to:* Euphoria , a genus of scarab beetles* Euphoria, a genus name previously used for the longan and other trees...
with Oxytrex than with oxycodone alone. Further study is needed. Less physical dependence
Physical dependence
Physical dependence refers to a state resulting from chronic use of a drug that has produced tolerance and where negative physical symptoms of withdrawal result from abrupt discontinuation or dosage reduction...
has been shown with the addition of the ULD naltrexone. If tolerance is delayed, the need to self-medicate may decrease leading to less abuse
Drug abuse
Substance abuse, also known as drug abuse, refers to a maladaptive pattern of use of a substance that is not considered dependent. The term "drug abuse" does not exclude dependency, but is otherwise used in a similar manner in nonmedical contexts...
of this opioid.