Drug Interaction:
Interacting drugs Naltrexone with- Opoid contg products decr Thioridazone incr
Naltrexone with-
Opoid contg products decr patients taking naltrexone may not benefit from opoid containing products such as cough/cold and antidiarrheal prepn. and opoid analgesics
Thioridazone incr lethargy ans somnolence have occured with concurrent use
Indication:
Narcotic addition
Interacting drugs Naltrexone with- Opoid contg products decr Thioridazone incr
Adverse Reaction:
Alcoholism- nausea, headache, dizziness, nervousness, fatigue, insomnia, vomiting, anxiety, somnolence, depression,suicidal ideation and attempted sicide have been reported in individuals on naltrexone , placibo and innconcurrent control groups undergoing treatment of alcoholism.
Narcotic addition-
CNS- difficulty in sleeping, anxiety, nervousness, headache, low energy, irritability, increased energy, dizziness, depression, paronia, fatigue, drowsiness, disoreitntation, restlessness, confusion,hallucinatins, nightmares, bad dreams.
GI- Abdominal cramps, pain.nausea, vomiting, loss of appetite diarrhea, constipation,excess gas, hemorrhoids, ulcer, dry mouth,hepatotoxicity.
Respiratory - Nasal congestion, rhinorrhea, sneezing, sore throat, excess mucous or phlegm, sinus trouble , heavy breathing ,hoarseness, cough, shortness of breath.
Musculoskeletal- joint/muscle pain, painful shoulders/legs/knees,tremors, twitching
GU- delayed ejaculation, decreased potency, increased frequency/disconfort during urination, increased or decreased sexual interest.
Contra-Indications:
Patients receiving opoid analgesics, opoid dependent patients.
Special precautions:
Monitoring- high rate of of suspicion for drug -related heaptic injury is critical if the occurrenace of liver damage induced by naltrexone is to be detected at theearliest possible time. Evaluatins using appropiate bateries of test to detect liver injury are recommended ta a frequency appropriate to the clinical situation andthe dose of naltexone.
Suicide- risk of suicide is increased in patients with substance abuse with without concomitant depression. The risk is not abated by treatment with naltexone.
Warnings-
Hepatotoxicity- naltrexone has the capacity to cause hepatocellular injury when given in excessives doses. It is contraindicated in acute hepatitis or liver failure,and its use in patients with active liver disease must be carefully considered in light of its hepatotoxic effects.
Abstinence precipitation/syndrome- unintended precipitation of abstinence or exacerbation of a preexisting subclinical abstinence may occur,therfore patients should remain opoid- free for a period of 7 to 10 days before starting naltrexone. Perform a naloxone challenge to exclude the possibility of precipitating a withdrawal reaction.
Severe opiod withdrwal syndrome- precipitated by accidental naltrexone ingestion have occured in opoid-dependent individuals. Withdrawal symptoms usually appear within 5 minutes of ingestion and may last up to 48 hours. Surmountable blockade- while natrexone is a potent antagonist with prolonged pharmacologic effect (24 to 72 hours) the blockade produced by naltrexone is surrmoumtable.
This poses a potential risk of individuals who attempt to overcome the blocakade by self-administering large amounts of opoids. Any attempt by a patient to overcome the antagonism by taking opoids is very dangerous. Use with narcotics- patients taking natrexone may not benefit from opiod-containg medicines such as cough and cold preparations,antidiarrheal preparations and opoid analgesics. Use a non-opoid containing alterenative if available.
Pregnancy- use naltexone in pregnancy only when the potential benefit justifies the risk to the fetus.
Lactation- excercise caution when naltexone is administered to a nursing mother.
Children- safety for use in children < 18 years of age has not been established.
Dosages/ Overdosage Etc:
Indications:
Narcotic addition
Dosage:
A dose of 50mg once daily is recommended for most patients
Overdosage-
Symptoms Treatment In acute toxicity studies in animals death was due 1. Treat symptomatically to clonictonic convulsions orrespiratory failure
Patient Information:
1. Patients should wear identification indicating naltrexone use.
2. If patients attempt self-administration of heroin or any other opiate in small
doses, they will perceive no effect. Self administration of large doses of
heroin or other narcotics can overcome the blockade and may cause coma,
serious injury or death.
Ref - USP PDI Vol II 17th Edition (1997)
1.Allergies-
Tell your doctor if you have ever had any unusual or allergic reaction to
Naltrexone. Also tell your healthcare care professional if you are allergic
to any other substances such as foods. preservatives or dyes.
2.Pregnancy-
Studies have not been done in humans. However, studies in animals
has not shown to cause unwanted effects when given in very large doses.
3. Breast-feeding-
It is known whether natrxone passes into breast milk. However, this medicine
has not been reported to cause problems in nursing babies
4.Children-
Natrxone has been studied only in adult patients and there is no specific
information about it use in patients up to 18 years of age..
5.Older adults-
There is no specific information comparing use of natrxone in the elderly with use
in other age groups
7. Other medical problems-
Make sure you tell your doctor if you have any other medical problems
especially-
Hepatitis or other liver disease- the chance of side effects may be increased
Pharmacology/ Pharmacokinetics:
Pharmacology:
Naltrexone, a pure opoid antagonist, markedly attentuates or completely reversibly blocks the subjective effects of IV opoids. When coadministered with morphine on a chronic basis, it blocks the physical dependence of morphine, heroin and other opoids.
Pharmacokinetics:
Although well absorbed orally, naltrexone is subject to significant first pass metabolism with oral bioavailabilty estimates ranging from 5% to 40%.. naltrexone undergoes rapid and nearly complete absorption with about 96% of the dose absorbed from the GI tract.
Pregnancy and lactation:
Pregnancy:
Use naltrexone in pregnancy only when the potential benefits justifies the risk to the fetus.
Lactation:
Excercise caution while administering to a nursing mother.
Children-
Safety for use in children < 18 years of age has not been established.
Manufacturer Details