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

Narcotic addition 

Interacting drugs Naltrexone with- Opoid contg products decr Thioridazone incr

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.

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

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:

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.