Warnings for Tuxarin-ER
Included as part of the "PRECAUTIONS" Section
Precautions for Tuxarin-ER
Ultra-Rapid Metabolism Of Codeine And Other Risk Factors For Life-Threatening Respiratory Depression In Children
Life-threatening respiratory depression and death have occurred in children who received codeine. Codeine is subject to variability in metabolism based upon CYP2D6 genotype (described below), which can lead to an increased exposure to the active metabolite morphine. Based upon post-marketing reports, children less than 12 years old appear to be more susceptible to the respiratory depressant effects of codeine, particularly if there are risk factors for respiratory depression. For example, many reported cases of death occurred in the post-operative period following tonsillectomy and/or adenoidectomy, and many of the children had evidence of being ultra-rapid metabolizers of codeine. Furthermore, children with obstructive sleep apnea who are treated with codeine for post-tonsillectomy and/or adenoidectomy pain may be particularly sensitive to its respiratory depressant effect. Because of the risk of life-threatening respiratory depression and death:
- TUXARIN ER is contraindicated in all children younger than 12 years of age [see CONTRAINDICATIONS].
- TUXARIN ER is contraindicated for post-operative management in pediatric patients younger than 18 years of age following tonsillectomy and/or adenoidectomy [see CONTRAINDICATIONS].
- Avoid the use of TUXARIN ER in adolescents 12 to 18 years of age who have other risk factors that may increase their sensitivity to the respiratory depressant effects of codeine. Risk factors include conditions associated with hypoventilation, such as postoperative status, obstructive sleep apnea, obesity, severe pulmonary disease, neuromuscular disease, and concomitant use of other medications that cause respiratory depression.
- When prescribing codeine for adolescents, healthcare providers should choose the lowest effective dose for the shortest period of time and inform patients and caregivers about these risks and the signs of morphine overdose [see OVERDOSE].
Nursing Mothers
At least one death was reported in a nursing infant who was exposed to high levels of morphine in breast milk because the mother was an ultra-rapid metabolizer of codeine. Breastfeeding is not recommended during treatment with TUXARIN ER [see Use In Specific Populations].
CYP2D6 Genetic Variability
Ultra-rapid Metabolizer
Some individuals may be ultra-rapid metabolizers because of a specific CYP2D6 genotype (e.g., gene duplications denoted as *1/*1×N or *1/*2×N). The prevalence of this CYP2D6 phenotype varies widely and has been estimated at 1 to 10% for Whites (European, North American), 3 to 4% for Blacks (African Americans), 1 to 2% for East Asians (Chinese, Japanese, Korean), and may be greater than 10% in certain ethnic groups (i.e., Oceanian, Northern African, Middle Eastern, Ashkenazi Jews, Puerto Rican). These individuals convert codeine into its active metabolite, morphine, more rapidly and completely than other people. This rapid conversion results in higher than expected serum morphine levels.
Even at labeled dosage regimens, individuals who are ultra-rapid metabolizers may have life-threatening or fatal respiratory depression or experience signs of overdose (such as extreme sleepiness, confusion, or shallow breathing) [see OVERDOSE] . Therefore, individuals who are ultra-rapid metabolizers should not use TUXARIN ER.
Risks From Concomitant Use With Benzodiazepines Or Other CNS Depressants
Concomitant use of opioids, including TUXARIN ER, with benzodiazepines, or other CNS depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. Because of these risks, avoid use of opioid cough medications in patients taking Benzodiazepines, other CNS depressants, or alcohol [see DRUG INTERACTIONS].
Observational studies have demonstrated that concomitant use of opioid analgesics and benzodiazepines increases the risk of drug-related mortality compared to use of opioids alone. Because of similar pharmacologic properties, it is reasonable to expect similar risk with concomitant use of opioid cough medications and benzodiazepines, other CNS depressants, or alcohol.
Advise both patients and caregivers about the risks of respiratory depression and sedation if TUXARIN ER is used with benzodiazepines, alcohol, or other CNS depressants. [see PATIENT INFORMATION]
Respiratory Depression
Codeine, one of the active ingredients in TUXARIN ER, produces dose-related respiratory depression by directly acting on brain stem respiratory centers.
Overdose of codeine in adults has been associated with fatal respiratory depression, and the use of codeine in children has been associated with fatal respiratory depression. Exercise caution when administering TUXARIN ER because of the potential for respiratory depression. If respiratory depression occurs, discontinue TUXARIN ER and use naloxone hydrochloride when indicated to antagonize the effect and other supportive measures as necessary. [see OVERDOSE].
Drug Dependence
Codeine can produce drug dependence of the morphine type and, therefore, has the potential for being abused. Psychological dependence, physical dependence, and tolerance may develop upon repeated administration of TUXARIN ER. Prescribe and administer TUXARIN ER with the same degree of caution appropriate to the use of other opioid drugs. [see Drug Abuse And Dependence]
Head Injury And Increased Intracranial Pressure
The respiratory depression effects of opioids and their capacity to elevate cerebrospinal fluid pressure may be markedly exaggerated in the presence of head injury, other intracranial lesions, or a pre-existing increase in intracranial pressure. Furthermore, opioids produce adverse reactions that may obscure the clinical course of patients with head injuries. The use of TUXARIN ER should be avoided in these patients.
Activities Requiring Mental Alertness
Codeine and chlorpheniramine, the active ingredients in TUXARIN ER, may produce marked drowsiness and impair the mental and/or physical abilities required for the performance of potentially hazardous tasks such as driving a car or operating machinery. Advise patients to avoid engaging in hazardous tasks requiring mental alertness and motor coordination after ingestion of TUXARIN ER. Concurrent use of TUXARIN ER with alcohol or other central nervous system depressants should be avoided because additional impairment of central nervous system performance may occur.
Obstructive Bowel Disease
Chronic use of opioids, including codeine, may result in obstructive bowel disease especially in patients with underlying intestinal motility disorders. Codeine may cause or aggravate constipation. Use with caution in patients with underlying intestinal motility disorders.
Acute Abdominal Conditions
TUXARIN ER should be used with caution in patients with acute abdominal conditions since the administration of codeine may obscure the diagnosis or clinical course of patients with acute abdominal conditions. The concurrent use of other anticholinergics with codeine may produce paralytic ileus. [see DRUG INTERACTIONS]
Special Risk Patients
As with other opioids, TUXARIN ER should be used with caution in elderly or debilitated patients and those with asthma, persistent or chronic cough, hypothyroidism, Addison's disease, prostatic hypertrophy or urethral stricture. The usual precautions should be observed and the possibility of respiratory depression should be kept in mind.
Patient Counseling Information
Advise the patient to read the FDA-approved patient labeling (PATIENT INFORMATION).
Ultra-Rapid Metabolism OCodeine And Other Risk Factors For Life-threatening Respiratory Depression In Children
Advise patients of the risks of respiratory depression and death with TUXARIN ER in children younger than 18 years of age. Advise patients that TUXARIN ER should not be used in children younger than 12 years of age or in a child younger than 18 years of age for treatment after tonsillectomy and/or adenoidectomy [see WARNINGS AND PRECAUTIONS].
Overdosage
Advise patients not to increase the dose or dosing frequency of TUXARIN ER because serious adverse events such as respiratory depression may occur with overdosage. [see WARNINGS AND PRECAUTIONS; OVERDOSE]
Interactions With Benzodiazepines And Other Central Nervous System Depressants
Inform patients and caregivers that potentially fatal additive effects may occur if TUXARIN ER is used with benzodiazepines or other CNS depressants, including alcohol. Because of this risk, patients should avoid concomitant use of TUXARIN ER with benzodiazepines or other CNS depressants, including alcohol [see WARNINGS AND PRECAUTIONS, DRUG INTERACTIONS].
Activities Requiring Mental Alertness
Caution patients that TUXARIN ER may produce marked drowsiness and impair the mental and/or physical abilities required for the performance of potentially hazardous tasks such as driving a car or operating machinery. [see WARNINGS AND PRECAUTIONS]
Controlled Substance Status/Potential For Abuse And Dependence
Caution patients that TUXARIN ER contains codeine and can produce drug dependence. [see Drug Abuse And Dependence].
Lactation
Advise women that breastfeeding is not recommended during treatment with TUXARIN ER [see Use In Specific Populations].
Nonclinical Toxicology
Carcinogenesis, Mutagenesis, Impairment Of Fertility
Carcinogenicity, mutagenicity, and reproductive studies have not been conducted with TUXARIN ER however, published information is available for the active ingredients
Codeine
In 2-year studies in F344/N rats and B6C3F1 mice, codeine showed no evidence of tumorigenicity at dietary doses up to 70 and 400 mg/kg/day, respectively (approximately 9 and 25 times, respectively, the MRHDD dose for adults and children on a mg/m2 basis).
Codeine was not mutagenic in the in vitro bacterial reverse mutation assay or clastogenic in the in vitro Chinese hamster ovary (CHO) cell chromosomal aberration assay.
Fertility studies with codeine have not been conducted.
Chlorpheniramine
In 2-year studies in F344/N rats and B6C3F1 mice, chlorpheniramine maleate showed no evidence of tumorigenicity when administered 5 days/week at oral doses up to 30 and 50 mg/kg/day, respectively (approximately 25 and 20 times, respectively, the MRHDD on a mg/m2 basis).
Chlorpheniramine maleate was not mutagenic in the in vitro bacterial reverse mutation assay or the in vitro mouse lymphoma forward mutation assay. Chlorpheniramine maleate was clastogenic in the in vitro CHO cell chromosomal aberration assay.
Chlorpheniramine maleate had no effects on fertility in rats and rabbits at oral doses approximately 25 and 30 times, respectively, the MRHDD on a mg/m2 basis.
Use In Specific Populations
Pregnancy
Teratogenic Effects
Pregnancy Category C
There are no adequate and well-controlled studies of TUXARIN ER in pregnant women.
Reproductive toxicity studies have not been conducted with TUXARIN ER; however, studies are available with individual active ingredients or related active ingredients. Because animal reproduction studies are not always predictive of human response, TUXARIN ER should be used during pregnancy only if the benefit justifies the potential risk to the fetus.
Codeine
Codeine has embryolethal and fetotoxic effects in rats. In a study in which pregnant rats were dosed throughout organogenesis, a dose approximately 15 times the maximum recommended human daily dose (MRHDD; on a mg/m2 basis at an oral maternal dose of 120 mg/kg/day) increased resorptions and decreased fetal weight; however, these effects occurred in the presence of maternal toxicity.
In studies in which rabbits and mice were dosed throughout organogenesis, codeine at doses approximately 7 and 35 times the MRHDD (on a mg/m2 basis at 30 and 600 mg/kg/day, respectively) produced no adverse developmental effects.
Chlorpheniramine
A retrospective study found a small, but statistically significant, association between maternal use of chlorpheniramine and inguinal hernia and eye or ear anomalies in children. Other retrospective studies have found that the frequency of congenital anomalies, in general, was not increased among offspring of women who took chlorpheniramine during pregnancy. The significance of these findings to the therapeutic use of chlorpheniramine in human pregnancy is not known.
In studies with chlorpheniramine in which pregnant rats and rabbits were dosed throughout organogenesis, oral doses up to approximately 25 and 30 times the MRHDD on a mg/m2 basis, respectively, produced no adverse developmental effects. However, when mice were dosed throughout pregnancy, a dose approximately 9 times the MRHDD (on a mg/m2 basis at an oral maternal dose of 20 mg/kg/day) was embryolethal, and postnatal survival was decreased when dosing was continued after parturition. Embryolethality was also observed when male and female rats were dosed with approximately 9 times the MRHDD (on a mg/m2 basis at an oral parental dose of 10 mg/kg/day) prior to mating.
Nonteratogenic Effects
Codeine
Babies born to mothers who have been taking opioids regularly prior to delivery will be physically dependent. The withdrawal signs include irritability and excessive crying, tremors, hyperactive reflexes, increased respiratory rate, increased stools, sneezing, yawning, vomiting, and fever. The intensity of the syndrome does not always correlate with the duration of maternal opioid use or dose.
Labor And Delivery
As with all opioids, administration of TUXARIN ER to the mother shortly before delivery may result in some degree of respiratory depression in the newborn, especially if higher doses are used.
Nursing Mothers
Risk Summary
Codeine and its active metabolite, morphine, are present in human milk. There are published studies and cases that have reported excessive sedation, respiratory depression, and death in infants exposed to codeine via breast milk. Women who are ultra-rapid metabolizers of codeine achieve higher than expected serum levels of morphine, potentially leading to higher levels of morphine in breast milk that can be dangerous in their breastfed infants. In women with normal codeine metabolism (normal CYP2D6 activity), the amount of codeine secreted into human milk is low and dose- dependent. There is no information on the effects of the codeine on milk production. Because of the potential for serious adverse reactions, including excess sedation, respiratory depression, and death in a breastfed infant, advise patients that breastfeeding is not recommended during treatment with TUXARIN ER [see WARNINGS AND PRECAUTIONS].
Clinical Considerations
If infants are exposed to TUXARIN ER through breast milk, they should be monitored for excess sedation and respiratory depression. Withdrawal symptoms can occur in breastfed infants when maternal administration of an opioid analgesic is stopped, or when breast-feeding is stopped.
Chlorpheniramine is excreted in human milk. The clinical significance is unknown; however, the anticholinergic action of chlorpheniramine may suppress lactation if taken prior to nursing.
Pediatric Use
Safety and effectiveness of TUXARIN ER in patients under 18 years of age have not been established.
Life-threatening respiratory depression and death have occurred in children who received codeine [see WARNINGS AND PRECAUTIONS] . In most of the reported cases, these events followed tonsillectomy and/or adenoidectomy, and many of the children had evidence of being ultra-rapid metabolizers of codeine (i.e., multiple copies of the gene for cytochrome P450 isoenzyme 2D6 or high morphine concentrations). Children with sleep apnea may be particularly sensitive to the respiratory depressant effects of codeine. Because of the risk of life-threatening respiratory depression and death:
- TUXARIN ER is contraindicated in all children younger than 12 years of age [see CONTRAINDICATIONS].
- TUXARIN ER is contraindicated for post-operative management in pediatric patients younger than 18 years of age following tonsillectomy and/or adenoidectomy [see CONTRAINDICATIONS].
- Avoid the use of TUXARIN ER in adolescents 12 to 18 years of age who have other risk factors that may increase their sensitivity to the respiratory depressant effects of codeine. Risk factors include conditions associated with hypoventilation, such as postoperative status, obstructive sleep apnea, obesity, severe pulmonary disease, neuromuscular disease, and concomitant use of other medications that cause respiratory depression. [see WARNINGS AND PRECAUTIONS].
Geriatric Use
Clinical efficacy and safety studies have not been conducted with TUXARIN ER. Other reported clinical experience with the individual active ingredients of TUXARIN ER did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. In general, dose selection for an elderly patient should be made with caution, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.
Renal Impairment
Pharmacokinetics of TUXARIN ER has not been characterized in renal impairment subjects.
Both codeine phosphate and chlorpheniramine maleate are cleared substantially by the kidney. As such, impaired renal function could potentially lead to the risk of decreased clearance and thereby increased retention or systemic levels of both these drugs. TUXARIN ER should be used with caution in patients with severe renal impairment.
Hepatic Impairment
Pharmacokinetics of TUXARIN ER has not been characterized in hepatic impairment subjects. Both codeine and chlorpheniramine maleate are extensively metabolized by liver before elimination from the body. As such, impaired hepatic function could potentially lead to the risk of decreased metabolism and thereby increased systemic levels of both these drugs. TUXARIN ER should be used with caution in patients with severe hepatic impairment.