Components:
Method of action:
Treatment option:
Medically reviewed by Fedorchenko Olga Valeryevna, PharmD. Last updated on 10.04.2022
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For use as an additional therapy within a comprehensive treatment program including psychological guidance for detoxified patients who have been opioid-dependent & alcohol dependence to support abstinence.
Use in adults
Naltrexon Vitaflo treatment should be initiated and supervised by suitable qualified physicians.
The initial dose of Naltrexon Vitaflo hydrochloride should be 25 mg (half a tablet) for opioid-dependent patient followed by the usual dose of one tablet per day (= 50 mg Naltrexon Vitaflo hydrochloride)
A missed dose can be managed by providing 1 tablet per day each day till the next regular dosage-administration.
Naltrexon Vitaflo administered to opioid-dependent persons can cause life-threatening withdrawal symptoms. Patients suspected of using or being addicted to opioids must undergo a naloxone provocation test , unless it can be verified that the patient has not taken any opioids for 7-10 days (urine test) prior to the initiation of treatment with Naltrexon Vitaflo.
As Naltrexon Vitaflo is an adjunctive therapy and the full recovery process in opioid-dependent patients is individually variable, no standard duration of treatment can be stated; an initial period of three months should be considered. However, prolonged administration may be necessary.
The recommended dose for alcohol dependence to support abstinence is 50 mg per day (1 tablet). A dose of over 150 mg on any single day is not recommended, since this can lead to a higher incidence of side effects.
As Naltrexon Vitaflo hydrochloride is an adjunctive therapy and the full recovery process from alcohol dependence is individually variable, no standard duration of treatment can be stated; an initial period of three months should be considered. However, prolonged administration may be necessary
The dosage-regimen can be modified in order to improve compliance to a three-times-a-week dosing schedule as follows: administration of 2 tablets (=100 mg Naltrexon Vitaflo hydrochloride) on Monday and on Wednesday and 3 tablets (=150 mg Naltrexon Vitaflo hydrochloride) on Friday.
Paediatric population
Naltrexon Vitaflo should not be used in children and adolescents under 18 years of age, since clinical data in this age-group are lacking. Safe use in children has not been established.
Older people
There are insufficient data on the safety and efficacy of Naltrexon Vitaflo for this indication in elderly patients.
Use in adults
Naltrexone treatment should be initiated and supervised by suitable qualified physicians.
The initial dose of Naltrexon Vitaflo should be 25 mg (half a tablet) for opioid-dependent patient followed by the usual dose of one tablet per day (= 50 mg Naltrexon Vitaflo)
A missed dose can be managed by providing 1 tablet per day each day till the next regular dosage-administration.
Naltrexone administered to opioid-dependent persons can cause life-threatening withdrawal symptoms. Patients suspected of using or being addicted to opioids must undergo a naloxone provocation test , unless it can be verified that the patient has not taken any opioids for 7-10 days (urine test) prior to the initiation of treatment with naltrexone.
As Naltrexone is an adjunctive therapy and the full recovery process in opioid-dependent patients is individually variable, no standard duration of treatment can be stated; an initial period of three months should be considered. However, prolonged administration may be necessary.
The recommended dose for alcohol dependence to support abstinence is 50 mg per day (1 tablet). A dose of over 150 mg on any single day is not recommended, since this can lead to a higher incidence of side effects.
As Naltrexon Vitaflo is an adjunctive therapy and the full recovery process from alcohol dependence is individually variable, no standard duration of treatment can be stated; an initial period of three months should be considered. However, prolonged administration may be necessary
The dosage-regimen can be modified in order to improve compliance to a three-times-a-week dosing schedule as follows: administration of 2 tablets (=100 mg Naltrexon Vitaflo) on Monday and on Wednesday and 3 tablets (=150 mg Naltrexon Vitaflo) on Friday.
Paediatric population
Naltrexone should not be used in children and adolescents under 18 years of age, since clinical data in this age-group are lacking. Safe use in children has not been established.
Older people
There are insufficient data on the safety and efficacy of naltrexone for this indication in elderly patients.
- Severe renal impairment
- Severe hepatic impairment
- Acute hepatitis
- Opioid addicted patients with a current abuse of opioids since an acute withdrawal syndrome may ensue.
- Positive screening result for opioids or after failure of the naloxone provocation test.
- for use in conjunction with an opioid - containing medication
- in combination with methadone.
In accordance to national guidance the therapy should be initiated and supervised by a physician experienced in treatment of opioid-addicted and alcohol-addicted patients
High dose opioid intake, concomitant with Naltrexon Vitaflo treatment, can lead to life-threatening opioid poisoning from respiratory and circulatory impairment.
Should Naltrexon Vitaflo be used in opioid-dependent patients a withdrawal syndrome may occur rapidly: the first symptoms can occur within 5 minutes, the last after 48 hours. The treatment of withdrawal symptoms is symptomatic.
It is not uncommon for alcohol abusing individuals to show signs of impaired hepatic function. Abnormal hepatic function test parameters have been reported in obese and elderly patients receiving Naltrexon Vitaflo in dosages higher than recommended (up to 300 mg/day). Hepatic function controls should be made before and during treatment. Special attention should be paid to patients with hepatic enzyme levels in serum exceeding three times the normal value and patients with renal impairment.
Liver function test abnormalities have been reported in obese and elderly patients taking Naltrexon Vitaflo who have no history of drug abuse. Liver function tests should be carried out both before and during treatment.
Patients must be warned against the concomitant use of opioids (e.g. opioids in cough medication, opioids in symptomatic medication for the treatment of common colds, or opioids contained in anti diarrhoeal agents, etc.) during Naltrexon Vitaflo treatment.
Naltrexon Vitaflo treatment must begin only when the opioid has been discontinued for a sufficiently long period (about 5 to 7 days for heroin and at least 10 days for methadone).
If the patient needs opioid treatment, e.g. opioid analgesia or anesthesia in emergency situations, the dose needed may be higher than normal. In these cases, the respiratory depression and circulatory effects will be more profound and longer lasting. Symptoms related to release of histamine (generalized erythema, diaphoresis, itching and other skin and mucocutaneous manifestations) can also be manifested more easily. The patient requires specific attention and care in these situations.
During treatment with Naltrexon Vitaflo, painful conditions should be treated with non-opioid analgesia only.
Patients should be warned that large doses of opioids to overcome the blockade may after the cessation of the Naltrexon Vitaflo result in an acute opioid overdose, with possible fatal outcome.
Patients might be more sensitive to opioid containing medicines after treatment with Naltrexon Vitaflo.
Patients suspected of using or being addicted to opioids must undergo a naloxone provocation test, unless it can be verified that the patient has not taken any opioids for 7-10 days (urine test) prior to the initiation of treatment with Naltrexon Vitaflo.
A withdrawal syndrome precipitated by naloxone will be of shorter duration than withdrawal precipitated by Naltrexon Vitaflo.
The recommended procedure is as follows:
Intravenous provocation
- Intravenous injection of 0.2 mg naloxone
- If after 30 seconds no adverse reactions occur, a further i.v. injection of 0.6 mg naloxone may be administered.
- The patient should be observed continuously for 30 minutes for any detectable sign of withdrawal symptoms.
If any symptoms of withdrawal occur Naltrexon Vitaflo-therapy must not be undertaken. If the test-result is negative the treatment can be initiated. If any doubt exists that the patient is opioid-free, the challenge may be repeated with the dosage of 1.6 mg. If no reaction occurs after this, 25 mg of Naltrexon Vitaflo hydrochloride can be administered to the patient.
A naloxone hydrochloride provocation test should not be made in patients with clinically prominent withdrawal symptoms nor in any case of a positive urine test for opioids.
Naltrexon Vitaflo is extensively metabolised by the liver and excreted predominantly in the urine. Therefore, caution should be observed in administering the medicinal product to patients with impaired hepatic or renal function. Liver function tests should be carried out both before and during treatment.
The risk of suicide is known to increase in substance abusers, with or without concomitant depression. Treatment with Naltrexon Vitaflo tablet does not eliminate this risk.
Lactose
Patients with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption should not take this medicine.
In accordance to national guidance the therapy should be initiated and supervised by a physician experienced in treatment of opioid-addicted and alcohol-addicted patients
High dose opioid intake, concomitant with Naltrexone treatment, can lead to life-threatening opioid poisoning from respiratory and circulatory impairment.
Should naltrexone be used in opioid-dependent patients a withdrawal syndrome may occur rapidly: the first symptoms can occur within 5 minutes, the last after 48 hours. The treatment of withdrawal symptoms is symptomatic.
It is not uncommon for alcohol abusing individuals to show signs of impaired hepatic function. Abnormal hepatic function test parameters have been reported in obese and elderly patients receiving naltrexone in dosages higher than recommended (up to 300 mg/day). Hepatic function controls should be made before and during treatment. Special attention should be paid to patients with hepatic enzyme levels in serum exceeding three times the normal value and patients with renal impairment.
Liver function test abnormalities have been reported in obese and elderly patients taking naltrexone who have no history of drug abuse. Liver function tests should be carried out both before and during treatment.
Patients must be warned against the concomitant use of opioids (e.g. opioids in cough medication, opioids in symptomatic medication for the treatment of common colds, or opioids contained in anti diarrhoeal agents, etc.) during naltrexone treatment.
Naltrexone treatment must begin only when the opioid has been discontinued for a sufficiently long period (about 5 to 7 days for heroin and at least 10 days for methadone).
If the patient needs opioid treatment, e.g. opioid analgesia or anesthesia in emergency situations, the dose needed may be higher than normal. In these cases, the respiratory depression and circulatory effects will be more profound and longer lasting. Symptoms related to release of histamine (generalized erythema, diaphoresis, itching and other skin and mucocutaneous manifestations) can also be manifested more easily. The patient requires specific attention and care in these situations.
During treatment with naltrexone, painful conditions should be treated with non-opioid analgesia only.
Patients should be warned that large doses of opioids to overcome the blockade may after the cessation of the naltrexone result in an acute opioid overdose, with possible fatal outcome.
Patients might be more sensitive to opioid containing medicines after treatment with naltrexone.
Patients suspected of using or being addicted to opioids must undergo a naloxone provocation test, unless it can be verified that the patient has not taken any opioids for 7-10 days (urine test) prior to the initiation of treatment with naltrexone.
A withdrawal syndrome precipitated by naloxone will be of shorter duration than withdrawal precipitated by naltrexone.
The recommended procedure is as follows:
Intravenous provocation
- Intravenous injection of 0.2 mg naloxone
- If after 30 seconds no adverse reactions occur, a further i.v. injection of 0.6 mg naloxone may be administered.
- The patient should be observed continuously for 30 minutes for any detectable sign of withdrawal symptoms.
If any symptoms of withdrawal occur naltrexone-therapy must not be undertaken. If the test-result is negative the treatment can be initiated. If any doubt exists that the patient is opioid-free, the challenge may be repeated with the dosage of 1.6 mg. If no reaction occurs after this, 25 mg of Naltrexon Vitaflo can be administered to the patient.
A naloxone hydrochloride provocation test should not be made in patients with clinically prominent withdrawal symptoms nor in any case of a positive urine test for opioids.
Naltrexone is extensively metabolised by the liver and excreted predominantly in the urine. Therefore, caution should be observed in administering the medicinal product to patients with impaired hepatic or renal function. Liver function tests should be carried out both before and during treatment.
The risk of suicide is known to increase in substance abusers, with or without concomitant depression. Treatment with Naltrexone tablet does not eliminate this risk.
Lactose
Patients with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption should not take this medicine.
Naltrexon Vitaflo may impair the mental and/or physical abilities required for performance of potentially hazardous tasks such as driving a car or operating machinery.
Naltrexone may impair the mental and/or physical abilities required for performance of potentially hazardous tasks such as driving a car or operating machinery.
The following undesirable effects are ranked according to system organ class and to their frequency:
Very common (> 1/10)
Common (>1/100 to < 1/10)
Uncommon (>1/1,000 to < 1/100)
Rare (> 1/10,000 to < 1/1,000)
Very rare (< 1/10,000)
not known (cannot be estimated from the available data)
| MedDRA system organ class | |
| Infections and infestation | |
| Uncommon | Oral herpes |
| Tinea pedis | |
| Blood and lymphatic system disorders | |
| Uncommon | Lymphadenopathy |
| Rare | Idiopathic thrombocytopenic purpura |
| Metabolism and nutrition disorders | |
| Common | Decreased appetite |
| Psychiatric disorders: | |
| Very common | Nervousness |
| Anxiety | |
| Insomnia | |
| Common | Affective disorders |
| Despondency | |
| Irritability | |
| Mood swings | |
| Uncommon | Hallucination |
| Confusional state | |
| Depression | |
| Paranoia | |
| Disorientation | |
| Nightmare | |
| Agitation | |
| Libido disorder | |
| Abnormal dreams | |
| Rare | Suicidal ideation |
| Attempted suicide | |
| Very rare | Euphoria |
| Nervous system disorder | |
| Very common | Headache |
| Sleep disorders | |
| Restlessness | |
| Common | Dizziness |
| Shivering | |
| Vertigo | |
| Uncommon | Tremor |
| Somnolence | |
| Rare | Speech disorder |
| Eye disorders | |
| Common | Lacrimation increased |
| Uncommon | Vision-blurred Eye irritation |
| Photophobia | |
| Eye swelling | |
| Eye pain | |
| Asthenopia | |
| Ear and labyrinth disorders | |
| Uncommon | Ear discomfort |
| Ear pain | |
| Tinnitus | |
| Vertigo | |
| Cardiac disorders | |
| Common | Tachycardia |
| Palpitations | |
| Electrocardiogram change | |
| Vascular disorders | |
| Uncommon | Blood pressure fluctuation |
| Flushing | |
| Respiratory, thoracic and mediastinal disorder | |
| Common | Chest pain |
| Uncommon | Nasal congestion |
| Nasal discomfort | |
| Rhinorrhea | |
| Sneezing | |
| Oropharyngeal pain | |
| Sputum increased | |
| sinus disorder | |
| Dyspnoea | |
| Dysphonia | |
| Cough | |
| Yawning | |
| Gastrointestinal disorder | |
| Very common | Abdominal pain |
| Abdominal cramps | |
| Nausea or Inclination to vomit | |
| Vomiting | |
| Common | Diarrhoea |
| Constipation | |
| Uncommon | Flatulence |
| Haemorrhoids | |
| Ulcer | |
| Dry mouth | |
| Hepatobiliary disorders | |
| Uncommon | Liver disorder |
| blood bilirubin increased | |
| hepatitis | |
| During treatment an increase of liver transaminases may occur. After discontinuation of Naltrexon Vitaflo the transaminases decreased to baseline within several weeks. | |
| Skin and subcutaneous tissue disorder | |
| Common | Rash |
| Uncommon | Seborrhoea |
| Pruritus | |
| Acne | |
| Alopecia | |
| Very rare | Exanthema |
| Musculoskeletal and connective tissue disorders : | |
| Very common | Arthralgia |
| Myalgia | |
| Uncommon | Groin pain |
| Very Rare | Rhabdomyolysis |
| Renal and urinary disorders | |
| Common | Urine retention |
| Uncommon | Pollakiuria |
| Dysuria | |
| Reproductive system and breast disorders | |
| Common | Delayed ejaculation |
| Erectile dysfunction | |
| General disorder and administration site conditions | |
| Very common | Feebleness |
| Asthenia | |
| Common | Lack of appetite |
| Thirst | |
| Energy increased | |
| Chills | |
| Hyperhidrosis | |
| Uncommon | Increased appetite |
| weight loss | |
| weight gain | |
| Pyrexia | |
| Pain | |
| Peripheral coldness | |
| Feeling hot |
Reporting of suspected adverse reactions
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the national reporting system (To be completed nationally).
The following undesirable effects are ranked according to system organ class and to their frequency:
Very common (> 1/10)
Common (>1/100 to < 1/10)
Uncommon (>1/1,000 to < 1/100)
Rare (> 1/10,000 to < 1/1,000)
Very rare (< 1/10,000)
not known (cannot be estimated from the available data)
| MedDRA system organ class | |
| Infections and infestation | |
| Uncommon | Oral herpes |
| Tinea pedis | |
| Blood and lymphatic system disorders | |
| Uncommon | Lymphadenopathy |
| Rare | Idiopathic thrombocytopenic purpura |
| Metabolism and nutrition disorders | |
| Common | Decreased appetite |
| Psychiatric disorders: | |
| Very common | Nervousness |
| Anxiety | |
| Insomnia | |
| Common | Affective disorders |
| Despondency | |
| Irritability | |
| Mood swings | |
| Uncommon | Hallucination |
| Confusional state | |
| Depression | |
| Paranoia | |
| Disorientation | |
| Nightmare | |
| Agitation | |
| Libido disorder | |
| Abnormal dreams | |
| Rare | Suicidal ideation |
| Attempted suicide | |
| Very rare | Euphoria |
| Nervous system disorder | |
| Very common | Headache |
| Sleep disorders | |
| Restlessness | |
| Common | Dizziness |
| Shivering | |
| Vertigo | |
| Uncommon | Tremor |
| Somnolence | |
| Rare | Speech disorder |
| Eye disorders | |
| Common | Lacrimation increased |
| Uncommon | Vision-blurred Eye irritation |
| Photophobia | |
| Eye swelling | |
| Eye pain | |
| Asthenopia | |
| Ear and labyrinth disorders | |
| Uncommon | Ear discomfort |
| Ear pain | |
| Tinnitus | |
| Vertigo | |
| Cardiac disorders | |
| Common | Tachycardia |
| Palpitations | |
| Electrocardiogram change | |
| Vascular disorders | |
| Uncommon | Blood pressure fluctuation |
| Flushing | |
| Respiratory, thoracic and mediastinal disorder | |
| Common | Chest pain |
| Uncommon | Nasal congestion |
| Nasal discomfort | |
| Rhinorrhea | |
| Sneezing | |
| Oropharyngeal pain | |
| Sputum increased | |
| sinus disorder | |
| Dyspnoea | |
| Dysphonia | |
| Cough | |
| Yawning | |
| Gastrointestinal disorder | |
| Very common | Abdominal pain |
| Abdominal cramps | |
| Nausea or Inclination to vomit | |
| Vomiting | |
| Common | Diarrhoea |
| Constipation | |
| Uncommon | Flatulence |
| Haemorrhoids | |
| Ulcer | |
| Dry mouth | |
| Hepatobiliary disorders | |
| Uncommon | Liver disorder |
| blood bilirubin increased | |
| hepatitis | |
| During treatment an increase of liver transaminases may occur. After discontinuation of Naltrexone the transaminases decreased to baseline within several weeks. | |
| Skin and subcutaneous tissue disorder | |
| Common | Rash |
| Uncommon | Seborrhoea |
| Pruritus | |
| Acne | |
| Alopecia | |
| Very rare | Exanthema |
| Musculoskeletal and connective tissue disorders : | |
| Very common | Arthralgia |
| Myalgia | |
| Uncommon | Groin pain |
| Very Rare | Rhabdomyolysis |
| Renal and urinary disorders | |
| Common | Urine retention |
| Uncommon | Pollakiuria |
| Dysuria | |
| Reproductive system and breast disorders | |
| Common | Delayed ejaculation |
| Erectile dysfunction | |
| General disorder and administration site conditions | |
| Very common | Feebleness |
| Asthenia | |
| Common | Lack of appetite |
| Thirst | |
| Energy increased | |
| Chills | |
| Hyperhidrosis | |
| Uncommon | Increased appetite |
| weight loss | |
| weight gain | |
| Pyrexia | |
| Pain | |
| Peripheral coldness | |
| Feeling hot |
Reporting of suspected adverse reactions
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the national reporting system (To be completed nationally).
Symptoms
- There is limited clinical experience with Naltrexon Vitaflo overdose in patients.
- There was no evidence of toxicity in volunteers receiving 800 mg/day for seven days.
Treatment
- In case of overdose, patients should be monitored and treated symptomatically in a closely supervised environment.
Symptoms
- There is limited clinical experience with naltrexone overdose in patients.
- There was no evidence of toxicity in volunteers receiving 800 mg/day for seven days.
Treatment
- In case of overdose, patients should be monitored and treated symptomatically in a closely supervised environment.
Pharmacotherapeutic group: other nervous system drugs; drugs used in addictive disorders, ATC code: N07BB04
Naltrexon Vitaflo is a specific opioid antagonist with only minimal agonistic activity. It acts by stereospecific competition with receptors which are mainly located in the central and peripheral nervous system. Naltrexon Vitaflo competitively binds to these receptors and blocks the access for exogenously administered opioids.
Naltrexon Vitaflo treatment does not lead to physical or mental dependence. No tolerance for the opioid antagonising effect is seen.
Naltrexon Vitaflo Hydrochloride 50 mg film-coated tablets reduces the risk of relapse and supports abstinence from opioids.
Naltrexon Vitaflo Hydrochloride 50 mg film-coated tablets is a non-aversive therapy and does not cause reactions after opioid intake. Therefore it does not cause a disulfiram-type reaction.
The mechanism of action of Naltrexon Vitaflo in alcoholism is not completely elucidated, however an interaction with the endogenous opioid system is suspected to play an important role. Alcohol consumption in humans has been hypothesised to be reinforcing through an alcohol-induced stimulation of the endogenous opioid system.
Naltrexon Vitaflo is not an aversive therapy and does not cause a disulfiram-like negative reaction when alcohol is ingested.
The prominent effect of Naltrexon Vitaflo treatment of alcohol-addicted patients seems to be a reduction of the risk of a full relapse with uncontrolled binge-drinking after having consumed a limited amount of alcohol.
This gives the patient a “second chance†to escape the otherwise mutually reinforcing mechanisms of a full relapse with complete loss of control. Naltrexon Vitaflo also seems to have an effect on the primary craving as it is non-reinforcing on isolated consumption of limited amounts of alcohol.
Pharmacotherapeutic group: other nervous system drugs; drugs used in addictive disorders, ATC code: N07BB04
Naltrexone is a specific opioid antagonist with only minimal agonistic activity. It acts by stereospecific competition with receptors which are mainly located in the central and peripheral nervous system. Naltrexone competitively binds to these receptors and blocks the access for exogenously administered opioids.
Naltrexone treatment does not lead to physical or mental dependence. No tolerance for the opioid antagonising effect is seen.
Naltrexon Vitaflo 50 mg film-coated tablets reduces the risk of relapse and supports abstinence from opioids.
Naltrexon Vitaflo 50 mg film-coated tablets is a non-aversive therapy and does not cause reactions after opioid intake. Therefore it does not cause a disulfiram-type reaction.
The mechanism of action of naltrexone in alcoholism is not completely elucidated, however an interaction with the endogenous opioid system is suspected to play an important role. Alcohol consumption in humans has been hypothesised to be reinforcing through an alcohol-induced stimulation of the endogenous opioid system.
Naltrexone is not an aversive therapy and does not cause a disulfiram-like negative reaction when alcohol is ingested.
The prominent effect of naltrexone treatment of alcohol-addicted patients seems to be a reduction of the risk of a full relapse with uncontrolled binge-drinking after having consumed a limited amount of alcohol.
This gives the patient a “second chance†to escape the otherwise mutually reinforcing mechanisms of a full relapse with complete loss of control. Naltrexone also seems to have an effect on the primary craving as it is non-reinforcing on isolated consumption of limited amounts of alcohol.
Absorption
Naltrexon Vitaflo is rapidly and almost completely absorbed from the gastrointestinal tract after oral administration.
Biotransformation
It undergoes a liver first-pass effect and peak plasma concentration is reached within approximately one hour.
Naltrexon Vitaflo is hydroxylated in the liver basically to the main active metabolite 6-beta-naltrexol and, to a lesser extent, to 2-hydroxy-3-methoxy-6-beta-naltrexol.
The plasma-half-life of Naltrexon Vitaflo is approximately 4 hours, the average blood level is 8.55 mg/ml, and plasmaprotein-binding is 21%. The plasma-half-life of 6-beta-naltrexol is 13 hours.
Elimination
The medicinal product is excreted primarily renal. About 60% of the peroral dose is excreted within 48 hours as glucuronidised 6-beta-naltrexol and Naltrexon Vitaflo.
Absorption
Naltrexone is rapidly and almost completely absorbed from the gastrointestinal tract after oral administration.
Biotransformation
It undergoes a liver first-pass effect and peak plasma concentration is reached within approximately one hour.
Naltrexone is hydroxylated in the liver basically to the main active metabolite 6-beta-naltrexol and, to a lesser extent, to 2-hydroxy-3-methoxy-6-beta-naltrexol.
The plasma-half-life of naltrexone is approximately 4 hours, the average blood level is 8.55 mg/ml, and plasmaprotein-binding is 21%. The plasma-half-life of 6-beta-naltrexol is 13 hours.
Elimination
The medicinal product is excreted primarily renal. About 60% of the peroral dose is excreted within 48 hours as glucuronidised 6-beta-naltrexol and naltrexone.
Preclinical data revealed no special hazard for humans based on conventional studies of safety, pharmacology, repeated dose toxicity, genotoxicity and carcinogenic potential. However, there is some evidence on hepatotoxicity with increasing dose, since reversible increases of liver enzymes has been found in humans with therapeutic and higher doses.
Naltrexon Vitaflo (100 mg/kg, approximately 140 times the human therapeutic dose) caused a significant increase in pseudo-pregnancy in the rat. A decrease in the pregnancy rate of mated female rats also occurred. The relevance of these observations to human fertility is not known.
Naltrexon Vitaflo has been shown to have an embryocidal effect in the rat and rabbit when given in doses approximately 140 times the human therapeutic dose. This effect was demonstrated in rats dosed with 100 mg/kg of Naltrexon Vitaflo prior to and throughout gestation, and rabbits treated with 60 mg/kg of Naltrexon Vitaflo during the period of organogenesis.
Preclinical data revealed no special hazard for humans based on conventional studies of safety, pharmacology, repeated dose toxicity, genotoxicity and carcinogenic potential. However, there is some evidence on hepatotoxicity with increasing dose, since reversible increases of liver enzymes has been found in humans with therapeutic and higher doses.
Naltrexone (100 mg/kg, approximately 140 times the human therapeutic dose) caused a significant increase in pseudo-pregnancy in the rat. A decrease in the pregnancy rate of mated female rats also occurred. The relevance of these observations to human fertility is not known.
Naltrexone has been shown to have an embryocidal effect in the rat and rabbit when given in doses approximately 140 times the human therapeutic dose. This effect was demonstrated in rats dosed with 100 mg/kg of naltrexone prior to and throughout gestation, and rabbits treated with 60 mg/kg of naltrexone during the period of organogenesis.
Any unused medicinal product or waste material should be disposed of in accordance with local requirements.
However, we will provide data for each active ingredient
