Epic Naltrexone HCl Tabs Iss: 09/11 Size: 12.125 x 11.125 Fold Size: 1-1/8 x 1-1/8 Type: 6 pt. Side A Proof 5 10/25/11 DC
Naltrexone Hydrochloride Tablets USP, film coated Elimination
reported in the literature have employed the following dosing regimen: 100
receptor blockade. As a consequence, the patient may be in immediate danger
The renal clearance for naltrexone ranges from 30 to 127 mL/min and
mg on Monday, 100 mg on Wednesday, and 150 mg on Friday. This dosing
of suffering life endangering opioid intoxication (e.g., respiratory arrest,
suggests that renal elimination is primarily by glomerular filtration. In
schedule appeared to be acceptable to many naltrexone patients successfully
circulatory collapse). Patients should be told of the serious consequences of
comparison, the renal clearance for 6-b-naltrexol ranges from 230 to 369
maintaining their opioid-free state.
trying to overcome the opiate blockade (see PRECAUTIONS, Information for
mL/min, suggesting an additional renal tubular secretory mechanism. The
Patients). DESCRIPTION
urinary excretion of unchanged naltrexone accounts for less than 2% of an
Experience with the supervised administration of a number of potentially
There is also the possibility that a patient who has been treated with
Naltrexone hydrochloride, an opioid antagonist, is a synthetic congener of
oral dose; urinary excretion of unchanged and conjugated 6-b-naltrexol
hepatotoxic agents suggests that supervised administration and single doses
naltrexone will respond to lower doses of opioids than previously used,
oxymorphone with no opioid agonist properties. Naltrexone hydrochloride
accounts for 43% of an oral dose. The pharmacokinetic profile of naltrexone
of naltrexone hydrochloride higher than 50 mg may have an associated
particularly if taken in such a manner that high plasma concentrations remain
differs in structure from oxymorphone in that the methyl group on the
suggests that naltrexone and its metabolites may undergo enterohepatic
increased risk of hepatocellular injury, even though three-times a week dosing
in the body beyond the time that naltrexone exerts its therapeutic effects. This
nitrogen atom is replaced by a cyclopropylmethyl group. Naltrexone
has been well-tolerated in the addict population and in initial clinical trials in
could result in potentially life-threatening opioid intoxication (respiratory
hydrochloride is also related to the potent opioid antagonist, naloxone, or
alcoholism. Clinics using this approach should balance the possible risks
compromise or arrest, circulatory collapse, etc.). Patients should be aware
n-allylnoroxymorphone. The chemical name for naltrexone hydrochloride is
Hepatic and Renal Impairment
against the probable benefits and may wish to maintain a higher index of
that they may be more sensitive to lower doses of opioids after naltrexone
Morphinan-6-one, 17-(cyclopropylmethyl)-4,5-epoxy-3,14-dihydroxy-,
Naltrexone appears to have extra-hepatic sites of drug metabolism and its
suspicion for drug-associated hepatitis and ensure patients are advised of the
hydrochloride, (5a)-. The structural formula is as follows:
major metabolite undergoes active tubular secretion (see Metabolism above).
need to report non-specific abdominal complaints (see PRECAUTIONS,
Adequate studies of naltrexone in patients with severe hepatic or renal
Information for Patients). Ultra Rapid Opioid Withdrawal
impairment have not been conducted (see PRECAUTIONS, Special Risk
Safe use of naltrexone in ultra rapid opiate detoxification programs has not
Patients). INDICATIONS AND USAGE
been established (see ADVERSE REACTIONS).
Naltrexone hydrochloride tablets are indicated in the treatment of alcohol
Clinical Trials
dependence and for the blockade of the effects of exogenously administered
PRECAUTIONS
Naltrexone has not been shown to provide any therapeutic benefit except as
When Reversal of Naltrexone Blockade is Required:
The efficacy of naltrexone as an aid to the treatment of alcoholism was tested
in placebo-controlled, outpatient, double blind trials. These studies used a
part of an appropriate plan of management for the addictions.
In an emergency situation in patients receiving fully blocking doses of
dose of naltrexone hydrochloride 50 mg once daily for 12 weeks as an adjunct
naltrexone, a suggested plan of management is regional analgesia, conscious
to social and psychotherapeutic methods when given under conditions that
CONTRAINDICATIONS
sedation with a benzodiazepine, use of non-opioid analgesics or general
enhanced patient compliance. Patients with psychosis, dementia, and
secondary psychiatric diagnoses were excluded from these studies.
1. Patients receiving opioid analgesics.
In a situation requiring opioid analgesia, the amount of opioid required may
Naltrexone hydrochloride is a white, crystalline compound. The hydrochloride
In one of these studies, 104 alcohol-dependent patients were randomized to
2. Patients currently dependent on opioids, including those currently
be greater than usual, and the resulting respiratory depression may be deeper
salt is soluble in water to the extent of about 100 mg/mL. Each film-coated
receive either naltrexone hydrochloride 50 mg once daily or placebo. In this
maintained on opiate agonists [e.g., methadone or LAAM (levo- alpha-
tablet, for oral administration, contains 50 mg of naltrexone hydrochloride. In
study, naltrexone proved superior to placebo in measures of drinking
addition each film-coated tablet contains the following inactive ingredients:
including abstention rates (51% vs. 23%), number of drinking days, and
A rapidly acting opioid analgesic which minimizes the duration of respiratory
carnauba wax powder, colloidal silicon dioxide, croscarmellose sodium,
relapse (31% vs. 60%). In a second study with 82 alcohol-dependent
3. Patients in acute opioid withdrawal (see WARNINGS).
depression is preferred. The amount of analgesic administered should be
hypromellose, hydroxypropyl cellulose, lactose anhydrous, magnesium
patients, the group of patients receiving naltrexone were shown to have lower
titrated to the needs of the patient. Non-receptor mediated actions may occur
stearate, microcrystalline cellulose, polyethylene glycol, titanium dioxide and
relapse rates (21% vs. 41%), less alcohol craving, and fewer drinking days
4. Any individual who has failed the naloxone challenge test or who has a
and should be expected (e.g., facial swelling, itching, generalized erythema,
compared with patients who received placebo, but these results depended on
or bronchoconstriction) presumably due to histamine release. CLINICAL PHARMACOLOGY
5. Any individual with a history of sensitivity to naltrexone or any other
Irrespective of the drug chosen to reverse naltrexone blockade, the patient
Pharmacodynamic Actions
The clinical use of naltrexone as adjunctive pharmacotherapy for the
components of this product. It is not known if there is any cross-sensitivity
should be monitored closely by appropriately trained personnel in a setting
Naltrexone hydrochloride is a pure opioid antagonist. It markedly attenuates
treatment of alcoholism was also evaluated in a multicenter safety study. This
with naloxone or the phenanthrene containing opioids.
equipped and staffed for cardiopulmonary resuscitation.
or completely blocks, reversibly, the subjective effects of intravenously
study of 865 individuals with alcoholism included patients with comorbid
psychiatric conditions, concomitant medications, polysubstance abuse and
6. Any individual with acute hepatitis or liver failure.
When co-administered with morphine, on a chronic basis, naltrexone blocks
HIV disease. Results of this study demonstrated that the side effect profile of
Severe opioid withdrawal syndromes precipitated by the accidental ingestion
the physical dependence to morphine, heroin and other opioids.
naltrexone appears to be similar in both alcoholic and opioid dependent
WARNINGS
of naltrexone have been reported in opioid-dependent individuals. Symptoms
Naltrexone has few, if any, intrinsic actions besides its opioid blocking
populations, and that serious side effects are uncommon. Hepatotoxicity
of withdrawal have usually appeared within five minutes of ingestion of
properties. However, it does produce some pupillary constriction, by an
naltrexone and have lasted for up to 48 hours. Mental status changes
In the clinical studies, treatment with naltrexone supported abstinence,
Naltrexone has the capacity to cause hepatocellular injury when given in
including confusion, somnolence and visual hallucinations have occurred.
The administration of naltrexone is not associated with the development of
prevented relapse and decreased alcohol consumption. In the uncontrolled
excessive doses.
Significant fluid losses from vomiting and diarrhea have required intravenous
tolerance or dependence. In subjects physically dependent on opioids,
study, the patterns of abstinence and relapse were similar to those observed
Naltrexone is contraindicated in acute hepatitis or liver failure, and its
fluid administration. In all cases patients were closely monitored and therapy
naltrexone will precipitate withdrawal symptomatology.
in the controlled studies. Naltrexone was not uniformly helpful to all patients,
use in patients with active liver disease must be carefully considered in
with non-opioid medications was tailored to meet individual requirements.
Clinical studies indicate that 50 mg of naltrexone hydrochloride will block the
and the expected effect of the drug is a modest improvement in the outcome
light of its hepatotoxic effects.
pharmacologic effects of 25 mg of intravenously administered heroin for
The margin of separation between the apparently safe dose of
Use of naltrexone does not eliminate or diminish withdrawal symptoms. If
periods as long as 24 hours. Other data suggest that doubling the dose of
naltrexone and the dose causing hepatic injury appears to be only
naltrexone is initiated early in the abstinence process, it will not preclude the
naltrexone hydrochloride provides blockade for 48 hours, and tripling the
five-fold or less. Naltrexone does not appear to be a hepatotoxin at the
patient’s experience of the full range of signs and symptoms that would be
dose of naltrexone hydrochloride provides blockade for about 72 hours.
Naltrexone has been shown to produce complete blockade of the euphoric
recommended doses.
experienced if naltrexone had not been started. Numerous adverse events are
Naltrexone blocks the effects of opioids by competitive binding (i.e.,
effects of opioids in both volunteer and addict populations. When
Patients should be warned of the risk of hepatic injury and advised to
known to be associated with withdrawal.
analogous to competitive inhibition of enzymes) at opioid receptors. This
administered by means that enforce compliance, it will produce an effective
stop the use of naltrexone and seek medical attention if they experience
makes the blockade produced potentially surmountable, but overcoming full
opioid blockade, but has not been shown to affect the use of cocaine or
symptoms of acute hepatitis. Special Risk Patients
naltrexone blockade by administration of very high doses of opiates has
resulted in excessive symptoms of histamine release in experimental subjects.
Naltrexone and its primary metabolite are excreted primarily in the urine, and
The mechanism of action of naltrexone in alcoholism is not understood;
There are no data that demonstrate an unequivocally beneficial effect of
Evidence of the hepatotoxic potential of naltrexone is derived primarily from
caution is recommended in administering the drug to patients with renal
however, involvement of the endogenous opioid system is suggested by
naltrexone on rates of recidivism among detoxified, formerly opioid-
a placebo controlled study in which naltrexone hydrochloride was
preclinical data. Naltrexone, an opioid receptor antagonist, competitively
dependent individuals who self- administer the drug. The failure of the drug
administered to obese subjects at a dose approximately five-fold that
binds to such receptors and may block the effects of endogenous opioids.
in this setting appears to be due to poor medication compliance.
recommended for the blockade of opiate receptors (300 mg per day). In that
Opioid antagonists have been shown to reduce alcohol consumption by
study, 5 of 26 naltrexone recipients developed elevations of serum
Caution should be exercised when naltrexone hydrochloride is administered
animals, and naltrexone has been shown to reduce alcohol consumption in
The drug is reported to be of greatest use in good prognosis opioid addicts
transaminases (i.e., peak ALT values ranging from a low of 121 to a high of
to patients with liver disease. An increase in naltrexone AUC of approximately
who take the drug as part of a comprehensive occupational rehabilitative
532; or 3 to 19 times their baseline values) after three to eight weeks of
5- and 10-fold in patients with compensated and decompensated liver
Naltrexone is not aversive therapy and does not cause a disulfiram-like
program, behavioral contract, or other compliance-enhancing protocol.
treatment. Although the patients involved were generally clinically
cirrhosis, respectively, compared with subjects with normal liver function has
reaction either as a result of opiate use or ethanol ingestion.
Naltrexone, unlike methadone or LAAM (levo- alpha-acetyl-methadol), does
asymptomatic and the transaminase levels of all patients on whom follow-up
been reported. These data also suggest that alterations in naltrexone
not reinforce medication compliance and is expected to have a therapeutic
was obtained returned to (or toward) baseline values in a matter of weeks, the
bioavailability are related to liver disease severity. Pharmacokinetics
effect only when given under external conditions that support continued use
lack of any transaminase elevations of similar magnitude in any of the 24
Naltrexone is a pure opioid receptor antagonist. Although well absorbed
placebo patients in the same study is persuasive evidence that naltrexone is
orally, naltrexone is subject to significant first pass metabolism with oral
a direct (i.e., not idiosyncratic) hepatotoxin.
The risk of suicide is known to be increased in patients with substance abuse
bioavailability estimates ranging from 5 to 40%. The activity of naltrexone is
This conclusion is also supported by evidence from other placebo controlled
with or without concomitant depression. This risk is not abated by treatment
believed to be due to both parent and the 6-b-naltrexol metabolite. Both
DO NOT ATTEMPT TREATMENT WITH NALTREXONE UNLESS, IN THE
studies in which exposure to naltrexone hydrochloride at doses above the
with naltrexone (see ADVERSE REACTIONS).
parent drug and metabolites are excreted primarily by the kidney (53% to
MEDICAL JUDGEMENT OF THE PRESCRIBING PHYSICIAN, THERE IS NO
amount recommended for the treatment of alcoholism or opiate blockade (50
79% of the dose), however, urinary excretion of unchanged naltrexone
REASONABLE POSSIBILITY OF OPIOID USE WITHIN THE PAST 7 TO 10
mg/day) consistently produced more numerous and more significant
Information for Patients
accounts for less than 2% of an oral dose and fecal excretion is a minor
DAYS. IF THERE IS ANY QUESTION OF OCCULT OPIOID DEPENDENCE,
elevations of serum transaminases than did placebo. Transaminase elevations
It is recommended that the prescribing physician relate the following
elimination pathway. The mean elimination half-life (T-1/2) values for
in 3 of 9 patients with Alzheimer's Disease who received naltrexone
information to patients being treated with naltrexone:
naltrexone and 6-b-naltrexol are 4 hours and 13 hours, respectively.
hydrochloride (at doses up to 300 mg/day) for 5 to 8 weeks in an open clinical
You have been prescribed naltrexone hydrochloride tablets as part of the
Naltrexone and 6-ß-naltrexol are dose proportional in terms of AUC and Cmax
comprehensive treatment for your alcoholism or drug dependence. You
over the range of 50 to 200 mg and do not accumulate after 100 mg daily
The placebo-controlled studies that demonstrated the efficacy of naltrexone
Although no cases of hepatic failure due to naltrexone administration have
should carry identification to alert medical personnel to the fact that you are
as an adjunctive treatment of alcoholism used a dose regimen of naltrexone
ever been reported, physicians are advised to consider this as a possible risk
taking naltrexone hydrochloride. A naltrexone medication card may be
hydrochloride 50 mg once daily for up to 12 weeks. Other dose regimens or
of treatment and to use the same care in prescribing naltrexone as they would
obtained from your physician and can be used for this purpose. Carrying the
Absorption
durations of therapy were not studied in these trials.
other drugs with the potential for causing hepatic injury.
identification card should help to ensure that you can obtain adequate
Following oral administration, naltrexone undergoes rapid and nearly
treatment in an emergency. If you require medical treatment, be sure to tell
complete absorption with approximately 96% of the dose absorbed from the
Physicians are advised that 5 to 15% of patients taking naltrexone for
Unintended Precipitation of Abstinence
the treating physician that you are receiving naltrexone therapy.
gastrointestinal tract. Peak plasma levels of both naltrexone and 6-b-naltrexol
alcoholism will complain of non-specific side effects, chiefly gastrointestinal
To prevent occurrence of an acute abstinence syndrome, or exacerbation
You should take naltrexone as directed by your physician. If you attempt to
upset. Prescribing physicians have tried using an initial 25 mg dose, splitting
of a pre-existing subclinical abstinence syndrome, patients must be
self-administer heroin or any other opiate drug, in small doses while on
the daily dose, and adjusting the time of dosing with limited success. No dose
opioid-free for a minimum of 7-10 days before starting naltrexone. Since
naltrexone, you will not perceive any effect. Most important, however, if you
Distribution
or pattern of dosing has been shown to be more effective than any other in
the absence of an opioid drug in the urine is often not sufficient proof that
attempt to self-administer large doses of heroin or any other opioid (including
The volume of distribution for naltrexone following intravenous
reducing these complaints for all patients. a patient is opioid-free, a naloxone challenge should be employed if the
methadone or LAAM) while on naltrexone, you may die or sustain serious
administration is estimated to be 1350 liters. In vitro tests with human
prescribing physician feels there is a risk of precipitating a withdrawal
plasma show naltrexone to be 21% bound to plasma proteins over the
reaction following administration of naltrexone. The naloxone challenge
Naltrexone is well-tolerated in the recommended doses, but may cause liver
Once the patient has been started on naltrexone hydrochloride, 50 mg once a
test is described in the DOSAGE AND ADMINISTRATION section.
injury when taken in excess or in people who develop liver disease from other
day will produce adequate clinical blockade of the actions of parenterally
causes. If you develop abdominal pain lasting more than a few days, white
Metabolism
administered opioids. As with many non-agonist treatments for addiction,
Attempt to Overcome Blockade
bowel movements, dark urine, or yellowing of your eyes, you should stop
The systemic clearance (after intravenous administration) of naltrexone is
naltrexone is of proven value only when given as part of a comprehensive
While naltrexone is a potent antagonist with a prolonged pharmacologic
taking naltrexone immediately and see your doctor as soon as possible.
~3.5 L/min, which exceeds liver blood flow (~1.2 L/min). This suggests both
plan of management that includes some measure to ensure the patient takes
effect (24 to 72 hours), the blockade produced by naltrexone is
that naltrexone is a highly extracted drug (>98% metabolized) and that extra
surmountable. This is useful in patients who may require analgesia, but poses
Laboratory Tests
hepatic sites of drug metabolism exist. The major metabolite of naltrexone is
a potential risk to individuals who attempt, on their own, to overcome the
A high index of suspicion for drug-related hepatic injury is critical if the
6-b-naltrexol. Two other minor metabolites are 2-hydroxy-3-methoxy-6-ß-
A flexible approach to a dosing regimen may be employed to enhance
blockade by administering large amounts of exogenous opioids. Indeed, any
occurrence of liver damage induced by naltrexone is to be detected at the
naltrexol and 2-hydroxy-3-methyl-naltrexone. Naltrexone and its metabolites
compliance. Thus, patients may receive 50 mg of naltrexone hydrochloride
attempt by a patient to overcome the antagonism by taking opioids is very
earliest possible time. Evaluations, using appropriate batteries of tests to
are also conjugated to form additional metabolic products.
every weekday with a 100 mg dose on Saturday or patients may receive 100 mg
dangerous and may lead to a fatal overdose. Injury may arise because the
detect liver injury are recommended at a frequency appropriate to the clinical
every other day, or 150 mg every third day. Several of the clinical studies
plasma concentration of exogenous opioids attained immediately following
situation and the dose of naltrexone.
their acute administration may be sufficient to overcome the competitive
Epic Naltrexone HCl Tabs Iss: 09/11 Size: 12.125 x 11.125 Fold Size: 1-1/8 x 1-1/8 Type: 6 pt. Side B Proof 5 10/25/11 DC
Naltrexone does not interfere with thin-layer, gas-liquid, and high pressure
cause of any other serious adverse reaction for the patient who is
in liver enzymes or bilirubin, hepatic function abnormalities or hepatitis,
Naloxone Challenge Test:
liquid chromatographic methods which may be used for the separation and
"opioid-free." It is critical to recognize that naltrexone hydrochloride can
palpitations, myalgia, anxiety, confusion, euphoria, hallucinations, insomnia,
The naloxone challenge test should not be performed in a patient showing
detection of morphine, methadone or quinine in the urine. Naltrexone may or
precipitate or exacerbate abstinence signs and symptoms in any individual
nervousness, somnolence, abnormal thinking, dyspnea, rash, increased
clinical signs or symptoms of opioid withdrawal, or in a patient whose urine
may not interfere with enzymatic methods for the detection of opioids
who is not completely free of exogenous opioids.
contains opioids. The naloxone challenge test may be administered by either
depending on the specificity of the test. Please consult the test manufacturer
Patients with addictive disorders, especially opioid addiction, are at risk for
the intravenous or subcutaneous routes.
multiple numerous adverse events and abnormal laboratory findings, including
Depression, suicide, attempted suicide and suicidal ideation have been
liver function abnormalities. Data from both controlled and observational
reported in the post-marketing experience with naltrexone used in the
Intravenous Drug Interactions
studies suggest that these abnormalities, other than the dose- related
treatment of opioid dependence. No causal relationship has been
Studies to evaluate possible interactions between naltrexone and drugs other
hepatotoxicity described above, are not related to the use of naltrexone.
demonstrated. In the literature, endogenous opioids have been theorized to
than opiates have not been performed. Consequently, caution is advised if the
Among opioid-free individuals, naltrexone administration at the recommended
contribute to a variety of conditions. In some individuals the use of opioid
Observe for 30 seconds for signs or symptoms of withdrawal.
concomitant administration of naltrexone and other drugs is required.
dose has not been associated with a predictable profile of serious adverse or
antagonists has been associated with a change in baseline levels of some
If no evidence of withdrawal, inject 0.6 mg of naloxone.
The safety and efficacy of concomitant use of naltrexone and disulfiram is
untoward events. However, as mentioned above, among individuals using
hypothalamic, pituitary, adrenal, or gonadal hormones. The clinical
unknown, and the concomitant use of two potentially hepatotoxic
opioids, naltrexone may cause serious withdrawal reactions (see
significance of such changes is not fully understood.
Observe for an additional 20 minutes.
medications is not ordinarily recommended unless the probable benefits
CONTRAINDICATIONS, WARNINGS, DOSAGE AND ADMINISTRATION).
Adverse events, including withdrawal symptoms and death, have been
Subcutaneous
Lethargy and somnolence have been reported following doses of naltrexone
Reported Adverse Events
reported with the use of naltrexone hydrochloride in ultra rapid opiate
Naltrexone has not been shown to cause significant increases in complaints
detoxification programs. The cause of death in these cases is not known (see
Patients taking naltrexone may not benefit from opioid containing medicines,
in placebo-controlled trials in patients known to be free of opioids for more
WARNINGS).
Observe for 20 minutes for signs or symptoms of withdrawal.
such as cough and cold preparations, antidiarrheal preparations, and opioid
than 7 to 10 days. Studies in alcoholic populations and in volunteers in
analgesics. In an emergency situation when opioid analgesia must be
clinical pharmacology studies have suggested that a small fraction of patients
Note: Individual patients, especially those with opioid dependence, may
administered to a patient receiving naltrexone, the amount of opioid required
may experience an opioid withdrawal-like symptom complex consisting of
With the exception of liver test abnormalities (see WARNINGS and
respond to lower doses of naloxone. In some cases, 0.1 mg IV naloxone has
may be greater than usual, and the resulting respiratory depression may be
tearfulness, mild nausea, abdominal cramps, restlessness, bone or joint pain,
PRECAUTIONS), results of laboratory tests, like adverse reaction reports,
deeper and more prolonged (see PRECAUTIONS).
myalgia, and nasal symptoms. This may represent the unmasking of occult
have not shown consistent patterns of abnormalities that can be attributed to
opioid use, or it may represent symptoms attributable to naltrexone. A number
Interpretation of the Challenge: Carcinogenesis, Mutagenesis and Impairment of Fertility
of alternative dosing patterns have been recommended to try to reduce the
Monitor vital signs and observe the patient for signs and symptoms of opioid
The following statements are based on the results of experiments in mice and
frequency of these complaints (see CLINICAL PHARMACOLOGY, Clinical
Idiopathic thrombocytopenic purpura was reported in one patient who may
withdrawal. These may include, but are not limited to: nausea, vomiting,
rats. The potential carcinogenic, mutagenic and fertility effects of the
Trials, Individualization of Dosage).
have been sensitized to naltrexone in a previous course of treatment with
dysphoria, yawning, sweating, tearing, rhinorrhea, stuffy nose, craving for
metabolite 6-b-naltrexol are unknown.
naltrexone. The condition cleared without sequelae after discontinuation of
opioids, poor appetite, abdominal cramps, sense of fear, skin erythema,
In a two-year carcinogenicity study in rats, there were small increases in the
Alcoholism
naltrexone and corticosteroid treatment.
disrupted sleep patterns, fidgeting, uneasiness, poor ability to focus, mental
numbers of testicular mesotheliomas in males and tumors of vascular origin
In an open label safety study with approximately 570 individuals with
lapses, muscle aches or cramps, pupillary dilation, piloerection, fever,
in males and females. The incidence of mesothelioma in males given
alcoholism receiving naltrexone, the following new-onset adverse reactions
DRUG ABUSE AND DEPENDENCE
changes in blood pressure, pulse or temperature, anxiety, depression,
naltrexone at a dietary dose of 100 mg/kg/ day (600 mg/m2/day; 16 times the
occurred in 2% or more of the patients: nausea (10%), headache (7%),
Naltrexone is a pure opioid antagonist. It does not lead to physical or
irritability, backache, bone or joint pains, tremors, sensations of skin crawling
recommended therapeutic dose, based on body surface area) was 6%,
dizziness (4%), nervousness (4%), fatigue (4%), insomnia (3%), vomiting
psychological dependence. Tolerance to the opioid antagonist effect is not
or fasciculations. If signs or symptoms of withdrawal appear, the test is
compared with a maximum historical incidence of 4%. The incidence of
(3%), anxiety (2%) and somnolence (2%).
positive and no additional naloxone should be administered.
vascular tumors in males and females given dietary doses of 100 mg/kg/day
(600 mg/m2/day) was 4% but only the incidence in females was increased
Depression, suicidal ideation, and suicidal attempts have been reported in all
OVERDOSAGE
Warning: If the test is positive, do NOT initiate naltrexone therapy. Repeat the
compared with a maximum historical control incidence of 2%. There was no
groups when comparing naltrexone, placebo, or controls undergoing
There is limited clinical experience with naltrexone overdosage in humans. In
challenge in 24 hours. If the test is negative, naltrexone therapy may be
evidence of carcinogenicity in a two-year dietary study with naltrexone in
one study, subjects who received 800 mg daily of naltrexone hydrochloride
started if no other contraindications are present. If there is any doubt about
for up to one week showed no evidence of toxicity.
the result of the test, hold naltrexone and repeat the challenge in 24 hours.
There was limited evidence of a weak genotoxic effect of naltrexone in one
RATE RANGES OF NEW ONSET EVENTS
In the mouse, rat and guinea pig, the oral LD50s were 1,100 to 1,550 mg/kg;
gene mutation assay in a mammalian cell line, in the Drosophila recessive
1,450 mg/kg; and 1,490 mg/kg; respectively. High doses of naltrexone
Alternative Dosing Schedules
lethal assay, and in non-specific DNA repair tests with E. coli. However, no
(generally ≥1,000 mg/kg) produced salivation, depression/reduced activity,
Once the patient has been started on naltrexone hydrochloride, 50 mg every
evidence of genotoxic potential was observed in a range of other in vitro
tremors, and convulsions. Mortalities in animals due to high-dose naltrexone
24 hours will produce adequate clinical blockade of the actions of parenterally
tests, including assays for gene mutation in bacteria, yeast, or in a second
administration usually were due to clonic-tonic convulsions and/or
administered opioids (i.e., this dose will block the effects of a 25 mg
mammalian cell line, a chromosomal aberration assay, and an assay for DNA
Although no causal relationship with naltrexone is suspected, physicians
intravenous heroin challenge). A flexible approach to a dosing regimen may
damage in human cells. Naltrexone did not exhibit clastogenicity in an in vivo
should be aware that treatment with naltrexone does not reduce the risk of
need to be employed in cases of supervised administration. Thus, patients
suicide in these patients (see PRECAUTIONS). Treatment of Overdosage
may receive 50 mg of naltrexone hydrochloride every weekday with a 100 mg
Naltrexone (100 mg/kg/day [600 mg/m2/day] PO; 16 times the recommended
In view of the lack of actual experience in the treatment of naltrexone
dose on Saturday, 100 mg every other day, or 150 mg every third day. The
therapeutic dose, based on body surface area) caused a significant increase in
Opioid Addiction
overdose, patients should be treated symptomatically in a closely supervised
degree of blockade produced by naltrexone may be reduced by these
pseudopregnancy in the rat. A decrease in the pregnancy rate of mated female
The following adverse reactions have been reported both at baseline and
environment. Physicians should contact a poison control center for the most
rats also occurred. There was no effect on male fertility at this dose level. The
during the naltrexone clinical trials in opioid addiction at an incidence rate of
There may be a higher risk of hepatocellular injury with single doses above
relevance of these observations to human fertility is not known.
50 mg, and use of higher doses and extended dosing intervals should balance
Difficulty sleeping, anxiety, nervousness, abdominal pain/cramps, nausea
DOSAGE AND ADMINISTRATION
the possible risks against the probable benefits (see WARNINGS and Pregnancy
and/or vomiting, low energy, joint and muscle pain, and headache.
IF THERE IS ANY QUESTION OF OCCULT OPIOID DEPENDENCE, PERFORM
CLINICAL PHARMACOLOGY, Clinical Trials, Individualization of Dosage). Teratogenic Effects:
A NALOXONE CHALLENGE TEST AND DO NOT INITIATE NALTREXONE
THERAPY UNTIL THE NALOXONE CHALLENGE IS NEGATIVE. Patient Compliance
Naltrexone has been shown to increase the incidence of early fetal loss when
Loss of appetite, diarrhea, constipation, increased thirst, increased energy,
Naltrexone should be considered as only one of many factors determining the
given to rats at doses ≥30 mg/kg/day (180 mg/m2/day; 5 times the
feeling down, irritability, dizziness, skin rash, delayed ejaculation, decreased
Treatment of Alcoholism
success of treatment. To achieve the best possible treatment outcome,
recommended therapeutic dose, based on body surface area) and to rabbits at
A dose of 50 mg once daily is recommended for most patients (see CLINICAL
appropriate compliance-enhancing techniques should be implemented for all
oral doses ≥60 mg/kg/day (720 mg/m2/day; 18 times the recommended
PHARMACOLOGY, Clinical Trials, Individualization of Dosage). The
components of the treatment program, including medication compliance.
therapeutic dose, based on body surface area). There was no evidence of
The following events occurred in less than 1% of subjects:
placebo-controlled studies that demonstrated the efficacy of naltrexone as an
teratogenicity when naltrexone was administered orally to rats and rabbits
adjunctive treatment of alcoholism used a dose regimen of naltrexone 50 mg
HOW SUPPLIED
during the period of major organogenesis at doses up to 200 mg/kg/day (32
once daily for up to 12 weeks. Other dose regimens or durations of therapy
Naltrexone Hydrochloride Tablets, USP 50 mg are yellow, round film-coated
and 65 times the recommended therapeutic dose, respectively, based on
nasal congestion, itching, rhinorrhea, sneezing, sore throat, excess mucus or
tablets, bisected on one side, debossed with “EL” on one side of the bisect
phlegm, sinus trouble, heavy breathing, hoarseness, cough, shortness of
A patient is a candidate for treatment with naltrexone if:
and “15” on the other side of the bisect. They are available in bottles of:
Rats do not form appreciable quantities of the major human metabolite,
6-b-naltrexol; therefore, the potential reproductive toxicity of the metabolites in
• the patient is willing to take a medicine to help with alcohol dependence
There are no adequate and well-controlled studies in pregnant women.
nose bleeds, phlebitis, edema, increased blood pressure, non-specific ECG
• the patient is opioid-free for 7 to 10 days
Naltrexone should be used during pregnancy only if the potential benefit
Store at 20° to 25°C (68° to 77°F) [See USP Controlled Room Temperature].
justifies the potential risk to the fetus.
• the patient does not have severe or active liver or kidney problems (Typical
Dispense in a tight, light-resistant container as defined in the USP, with a
Gastrointestinal: excessive gas, hemorrhoids, diarrhea, ulcer.
guidelines suggest liver function tests no greater than 3 times the upper
child-resistant closure (as required). Protect from light. Labor and Delivery
Whether or not naltrexone affects the duration of labor and delivery is
painful shoulders, legs or knees; tremors, twitching.
• the patient is not allergic to naltrexone, and no other contraindications are
Nursing Mothers
In animal studies, naltrexone and 6-b-naltrexol were excreted in the milk of
increased frequency of, or discomfort during, urination; increased or
Refer to CONTRAINDICATIONS, WARNINGS, and PRECAUTIONS sections
lactating rats dosed orally with naltrexone. Whether or not naltrexone is
excreted in human milk is unknown. Because many drugs are excreted in
Naltrexone should be considered as only one of many factors determining the
human milk, caution should be exercised when naltrexone is administered to
success of treatment of alcoholism. Factors associated with a good outcome
oily skin, pruritus, acne, athlete's foot, cold sores, alopecia.
in the clinical trials with naltrexone were the type, intensity, and duration of
treatment; appropriate management of comorbid conditions; use of
Pediatric Use
community-based support groups; and good medication compliance. To
The safe use of naltrexone in pediatric patients younger than 18 years old has
depression, paranoia, fatigue, restlessness, confusion, disorientation,
hallucinations, nightmares, bad dreams.
compliance-enhancing techniques should be implemented for all components
of the treatment program, especially medication compliance. ADVERSE REACTIONS
During two randomized, double-blind placebo-controlled 12-week trials to
eyes–blurred, burning, light sensitive, swollen, aching, strained;
Treatment of Opioid Dependence
evaluate the efficacy of naltrexone as an adjunctive treatment of alcohol
ears–"clogged," aching, tinnitus. Initiate treatment with Naltrexone using the following guidelines
dependence, most patients tolerated naltrexone well. In these studies, a total
1. Treatment should not be attempted unless the patient has remained
of 93 patients received naltrexone hydrochloride at a dose of 50 mg once
opioid-free for at least 7 to10 days. Self-reporting of abstinence from
daily. Five of these patients discontinued naltrexone because of nausea. No
increased appetite, weight loss, weight gain, yawning, somnolence, fever, dry
opioids in opioid addicts should be verified by analysis of the patient's
serious adverse events were reported during these two trials.
mouth, head "pounding," inguinal pain, swollen glands, "side" pains, cold feet,
urine for absence of opioids. The patient should not be manifesting
While extensive clinical studies evaluating the use of naltrexone in detoxified,
withdrawal signs or reporting withdrawal symptoms.
formerly opioid-dependent individuals failed to identify any single, serious
untoward risk of naltrexone use, placebo-controlled studies employing up to
2. If there is any question of occult opioid dependence, perform a naloxone
fivefold higher doses of naltrexone hydrochloride (up to 300 mg per day) than
Data collected from post-marketing use of naltrexone show that most events
challenge test. If signs of opioid withdrawal are still observed following
that recommended for use in opiate receptor blockade have shown that
usually occur early in the course of drug therapy and are transient. It is not
naloxone challenge, treatment with naltrexone should not be attempted.
naltrexone causes hepatocellular injury in a substantial proportion of patients
always possible to distinguish these occurrences from those signs and
The naloxone challenge can be repeated in 24 hours.
exposed at higher doses (see WARNINGS and PRECAUTIONS, Laboratory
symptoms that may result from a withdrawal syndrome. Events that have
been reported include anorexia, asthenia, chest pain, fatigue, headache, hot
3. Treatment should be initiated carefully, with an initial dose of 25 mg of
Aside from this finding, and the risk of precipitated opioid withdrawal,
flushes, malaise, changes in blood pressure, agitation, dizziness,
naltrexone hydrochloride. If no withdrawal signs occur, the patient may be
available evidence does not incriminate naltrexone, used at any dose, as a
hyperkinesia, nausea, vomiting, tremor, abdominal pain, diarrhea, elevations
Workplace stress is a serious issue, says Denise Barrett , but you can get a handle on it and turn it to your advantage There once was a time when a stressful day at the office meant donning a loincloth, leaving the cave and spearing the evening meal. Now, it’s technology and commuting we wrestle with as we strive to conquer deadlines and data. As modern medicine helps increase our life
Go For Research & Development Grants 100 ISSUES by Paul St. Clair, F.C.A., Peter Small, B. Bus, F.C.A., and Avinash Lakhan, BFA/LLB. C.A We are proud to provide you with the 100th Edition of • The Australian dollar was a regulated currency (it was our Client Newsletter. Our first newsletter was sent to clients in April, 1981. The newsletter has always been Our February, 1984 le