Codeine Phosphate and Chlorpheniramine Maleate

INDICATIONS AND USAGE TUXARIN ER is indicated for the temporary relief of cough and upper respiratory symptoms associated with allergy or the common cold in patients 18 years of age and older. TUXARIN ER is a combination of codeine, an opioid agonist; and chlorpheniramine, a histamine-1 (H 1 ) receptor antagonist, indicated for the temporary relief of cough and upper respiratory symptoms associated with allergy or the common cold in patients 18 years of age and older. ( 1 ) Important Limitations of Use ( 1 ) Not indicated for pediatric patients under 18 years of age. Because of the risks of addiction, abuse, and misuse with opioids, even at recommended doses, reserve TUXARIN ER for use in adult patients for whom the benefits of cough suppression are expected to outweigh the risks, and in whom an adequate assessment of the etiology of the cough has been made. Important Limitations of Use Not indicated for pediatric patients under 18 years of age [see Use in Specific Population (8.4) ]. Contraindicated in pediatric patients under 12 years of age [ see Contraindications (4) , Use in Specific Populations (8.4) ]. Contraindicated in pediatric patients 12 to 18 years of age after tonsillectomy or adenoidectomy [see Contraindications (4) , Use in Specific Populations (8.4) ]. Because of the risks of addiction, abuse, and misuse with opioids, even at recommended doses [ see Warnings and Precautions (5.1) ], reserve TUXARIN ER for use in adult patients for whom the benefits of cough suppression are expected to outweigh the risks, and in whom an adequate assessment of the etiology of the cough has been made.

DOSAGE AND ADMINISTRATION Adults 18 years of age and older : 1 tablet every 12 hours as needed, not to exceed 2 tablets in 24 hours. ( 2.2 ) Do not increase the dose or dosing frequency. ( 2.1 ) Prescribe for the shortest duration consistent with treatment goals. ( 2.3 ) Reevaluate patients with unresponsive cough in 5 days or sooner for possible underlying pathology. ( 2.3 ) Reevaluate patient prior to refilling. ( 2.3 ) 2.1 Important Dosage and Administration Instructions Administer TUXARIN ER by the oral route only. 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 (5.2) , Overdosage (10) ]. The dosage of TUXARIN ER should not be increased if cough fails to respond; an unresponsive cough should be reevaluated for possible underlying pathology [ see Dosage and Administration (2.3) , Warnings and Precautions (5.5) ]. 2.2 Recommended Dosage Adults 18 years of age and older: one tablet every 12 hours as needed, not to exceed 2 tablets in 24 hours. 2.3 Monitoring, Maintenance, and Discontinuation of Therapy Prescribe TUXARIN ER for the shortest duration that is consistent with individual patient treatment goals [ see Warnings and Precautions (5.1) ] Monitor patients closely for respiratory depression, especially within the first 24-72 hours of initiating therapy [ see Warnings and Precautions (5.2) ] . Reevaluate patients with unresponsive cough in 5 days or sooner for possible underlying pathology, such as foreign body or lower respiratory tract disease [ see Warnings and Precautions (5.5) ]. If a patient requires a refill, reevaluate the cause of the cough and assess the need for continued treatment with TUXARIN ER, the relative incidence of adverse reactions, and the development of addiction, abuse, or misuse [ see Warnings and Precautions (5.1) ]. Do not abruptly discontinue TUXARIN ER in a physically-dependent patient [ see Drug Abuse and Dependence (9.3) ]. When a patient who has been taking TUXARIN ER regularly and may be physically dependent no longer requires therapy with TUXARIN ER, taper the dose gradually, by 25% to 50% every 2 to 4 days, while monitoring carefully for signs and symptoms of withdrawal. If the patient develops these signs or symptoms, raise the dose to the previous level and taper more slowly, either by increasing the interval between decreases, decreasing the amount of change in dose, or both.

WARNINGS AND PRECAUTIONS See Boxed WARNINGS Life-threatening respiratory depression in patients with chronic pulmonary disease or in elderly, cachectic, or debilitated patients: Monitor closely, particularly during initiation of therapy. ( 5.5 ) Activities requiring mental alertness: Avoid engaging in hazardous tasks requiring mental alertness such as driving or operating machinery. ( 5.7 ) Risks of use in patients with head injury, impaired consciousness, increased intracranial pressure, or brain tumors: Avoid use. May increase intracranial pressure and obscure the clinical course of head injuries. ( 5.11 ) Seizures in patients with seizure disorders: Monitor during therapy. ( 5.12 ) Severe hypotension: Monitor during initiation of therapy. Avoid use in patients with circulatory shock. ( 5.14 ) Adrenal insufficiency: If diagnosed, treat with physiologic replacement of corticosteroids, and wean patient off of the opioid. ( 5.16 ) 5.1 Addiction, Abuse, and Misuse TUXARIN ER contains codeine, a Schedule III controlled substance. As an opioid, TUXARIN ER exposes users to the risks of addiction, abuse, and misuse [ see Drug Abuse and Dependence (9) ] , which can lead to overdose and death [ see Overdosage (10) ] . Reserve TUXARIN ER for use in adult patients for whom the benefits of cough suppression are expected to outweigh the risks, and in whom an adequate assessment of the etiology of the cough has been made. Assess each patient's risk prior to prescribing TUXARIN ER, prescribe TUXARIN ER for the shortest duration that is consistent with individual patient treatment goals , monitor all patients regularly for the development of addiction or abuse, and refill only after reevaluation of the need for continued treatment. Although the risk of addiction in any individual is unknown, it can occur in patients appropriately prescribed TUXARIN ER. Addiction can occur at recommended dosages and if the drug is misused or abused. Risks are increased in patients with a personal or family history of substance abuse (including drug or alcohol abuse or addiction) or mental illness (e.g., major depression). Opioids are sought by drug abusers and people with addiction disorders and are subject to criminal diversion. Consider these risks when prescribing or dispensing TUXARIN ER. Strategies to reduce these risks include prescribing the drug in the smallest appropriate quantity and advising the patient on the proper disposal of unused drug [ see Patient Counseling Information (17) ]. Contact local state professional licensing board or state controlled substances authority for information on how to prevent and detect abuse or diversion of this product. 5.2 Life-Threatening Respiratory Depression Serious, life-threatening, or fatal respiratory depression has been reported with the use of opioids, including codeine, one of the active ingredients in TUXARIN ER. Codeine produces dose-related respiratory depression by directly acting on the brain stem respiratory center that controls respiratory rhythm and may produce irregular and periodic breathing. Codeine is subject to variability in metabolism based upon CYP2D6 genotype, which can lead to an increased exposure to the active metabolite morphine [ see Warnings and Precautions (5.3) ]. Respiratory depression, if not immediately recognized and treated, may lead to respiratory arrest and death. Management of respiratory depression includes discontinuation of TUXARIN ER, close observation, supportive measures, and use of opioid antagonists (e.g. naloxone), depending on the patient's clinical status [ see Overdosage (10) ]. Carbon dioxide (CO 2 ) retention from opioid-induced respiratory depression can exacerbate the sedating effects of opioids. While serious, life-threatening, or fatal respiratory depression can occur at any time during the use of TUXARIN ER, the risk is greatest during the initiation of therapy, when TUXARIN ER is used concomitantly with other drugs that may cause respiratory depression [ see Warnings and Precautions (5.9) ], in patients with chronic pulmonary disease or decreased respiratory reserve, and in patients with altered pharmacokinetics or altered clearance (e.g. elderly, cachectic, or debilitated patients) [ see Warnings and Precautions (5.5) ]. To reduce the risk of respiratory depression, proper dosing of TUXARIN ER is essential [see Dosage and Administration (2.1) , Warnings and Precautions (5.6) ]. Monitor patients closely, especially within the first 24- 72 hours of initiating therapy or when used in patients at higher risk. Overdose of codeine in adults has been associated with fatal respiratory depression, and the use of codeine in children younger than 12 years of age has been associated with fatal respiratory depression when used as recommended [ see Warnings and Precautions (5.3) ]. Accidental ingestion of even one dose of TUXARIN ER, especially by children, can result in respiratory depression and death. 5.3 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 younger 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 (4) ]. TUXARIN ER is contraindicated for post-operative management in pediatric patients younger than 18 years of age following tonsillectomy and/or adenoidectomy [ see Contraindications (4) ]. 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 (5.9) , Use in Specific Populations (8.4) ] 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 Warnings and Precautions (5.1) , Overdosage (10) ]. Lactation 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 (8.2) ]. CYP2D6 Genetic Variability: Ultra-Rapid Metabolizers 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, mo

CONTRAINDICATIONS TUXARIN ER is contraindicated for: All children younger than 12 years of age [ see Warnings and Precautions (5.2 , 5.3 , 5.4) , Use in Specific Populations (8.4) ]. Postoperative management in children younger than 18 years of age following tonsillectomy and/or adenoidectomy [ see Warnings and Precautions (5.2 , 5.3) ]. TUXARIN ER is also contraindicated in patients with: Significant respiratory depression [see Warnings and Precautions (5.2) ] Acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment [ see Warnings and Precautions (5.5) ]. Known or suspected gastrointestinal obstruction, including paralytic ileus [ see Warnings and Precautions (5.10) ]. Concurrent use of monoamine oxidase inhibitors (MAOIs) or use of MAOIs within 14 days [ see Warnings and Precautions (5.13) , Drug Interactions (7.7) ]. Hypersensitivity to codeine, chlorpheniramine, or any of the inactive ingredients in TUXARIN ER [ see Adverse Reactions (6) ]. Persons known to be hypersensitive to certain other opioids may exhibit cross-reactivity to codeine. Children younger than 12 years of age ( 4 ) Significant respiratory depression. ( 4 ) Acute or severe bronchial asthma in an unmonitored setting or in absence of resuscitative equipment. ( 4 ) Known or suspected gastrointestinal obstruction, including paralytic ileus. ( 4 ) Concurrent use of monoamine oxidase inhibitor (MAOI) therapy or within the last 14 days. ( 4 ) Hypersensitivity to codeine or other opiates, chlorpheniramine, or any of the inactive ingredients in TUXARIN ER. ( 4 )

DRUG INTERACTIONS No specific drug interaction studies have been conducted with TUXARIN ER. Phenytoin : Avoid concomitant use; may increase phenytoin levels. ( 7.4 ) Serotonergic drugs : Concomitant use may result in serotonin syndrome. Discontinue if serotonin syndrome is suspected. ( 7.6 ) Muscle relaxants : Avoid concomitant use. ( 7.8 ) Diuretics: Codeine may reduce the efficacy of diuretics. Monitor for reduced effect. ( 7.9 ) Anticholinergic drugs : Concurrent use may cause paralytic ileus. ( 5.10 , 7.10 ) 7.1 Inhibitors of CYP3A4 The concomitant use of TUXARIN ER with CYP3A4 inhibitors, such as macrolide antibiotics (e.g., erythromycin), azole-antifungal agents (e.g. ketoconazole), or protease inhibitors (e.g., ritonavir), may result in an increase in codeine plasma concentrations with subsequently greater metabolism by cytochrome CYP2D6, resulting in greater morphine levels, which could increase or prolong adverse reactions and may cause potentially fatal respiratory depression, particularly when an inhibitor is added after a stable dose of TUXARIN ER is achieved [ see Warnings and Precautions (5.8) ]. After stopping a CYP3A4 inhibitor, as the effects of the inhibitor decline, it may result in lower codeine levels, greater norcodeine levels, and less metabolism via CYP2D6 with resultant lower morphine levels [ see Clinical Pharmacology (12.3) ], resulting in decreased opioid efficacy or a withdrawal syndrome in patients who had developed physical dependence to codeine. Avoid the use of TUXARIN ER while taking a CYP3A4 inhibitor. If concomitant use is necessary, monitor patients for respiratory depression and sedation at frequent intervals. 7.2 CYP3A4 Inducers The concomitant use of TUXARIN ER and CYP3A4 inducers, such as rifampin, carbamazepine, or phenytoin, can result in lower codeine levels, greater norcodeine levels, and less metabolism via 2D6 with resultant lower morphine levels [ see Clinical Pharmacology (12.3) ], resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence [ see Warnings and Precautions (5.8) ]. After stopping a CYP3A4 inducer, as the effects of the inducer decline, codeine plasma concentrations may increase with subsequently greater metabolism by cytochrome CYP2D6, resulting in greater morphine levels [ see Clinical Pharmacology (12.3) ], which could increase or prolong both the therapeutic effects and adverse reactions, and may cause serious respiratory depression. Avoid the use of TUXARIN ER in patients who are taking CYP3A4 inducers. If concomitant use of a CYP3A4 inducer is necessary, follow the patient for reduced efficacy. 7.3 Phenytoin Adverse event reports in the literature suggest a possible drug interaction involving increased serum phenytoin levels and phenytoin toxicity when chlorpheniramine and phenytoin are co-administered. The exact mechanism for this interaction is not known, however it is believed that chlorpheniramine may inhibit the hepatic metabolism of phenytoin. Avoid the use of TUXARIN ER while taking phenytoin. 7.4 Inhibitors of CYP2D6 Codeine is metabolized by CYP2D6 to form morphine. The concomitant use of TUXARIN ER and CYP2D6 inhibitors, such as paroxetine, fluoxetine, bupropion, or quinidine, can increase the plasma concentration of codeine, but can decrease the plasma concentration of active metabolite morphine, which could result in reduced efficacy [see Clinical Pharmacology (12.3) ]. After stopping a CYP2D6 inhibitor, as the effects of the inhibitor decline, the codeine plasma concentration will decrease but the active metabolite morphine plasma concentration will increase, which could increase or prolong adverse reactions and may cause potentially fatal respiratory depression [ see Clinical Pharmacology (12.3) ]. Avoid the use of TUXARIN ER in patients who are taking inhibitors of CYP2D6. 7.5 Benzodiazepines and Other CNS Depressants Due to additive pharmacologic effect, the concomitant use of benzodiazepines or other CNS depressants, including alcohol, other sedatives/hypnotics, anxiolytics, tranquilizers, muscle relaxants, general anesthetics, antipsychotics, and other opioids, can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death. Avoid the use of TUXARIN ER in patients who are taking benzodiazepines or other CNS depressants. [ see Warnings and Precautions (5.9) ] . 7.6 Serotonergic Drugs The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation. Discontinue TUXARIN ER if serotonin syndrome is suspected. 7.7 Monoamine Oxidase Inhibitors (MAOIs) TUXARIN ER is contraindicated in patients who are taking MAOIs (i.e., certain drugs used for depression, psychiatric or emotional conditions, or Parkinson's disease) or have taken MAOIs within 14 days [ see Contraindications (4) ]. MAOI interactions with opioids may manifest as serotonin syndrome or opioid toxicity (e.g., respiratory depression, coma) [ see Warnings and Precautions (5.13) ] . 7.8 Muscle Relaxants Codeine may enhance the neuromuscular blocking action of skeletal muscle relaxants and produce an increased degree of respiratory depression. Avoid the use of TUXARIN ER in patients taking muscle relaxants. If concomitant use is necessary, monitor patients for signs of respiratory depression that may be greater than otherwise expected. 7.9 Diuretics Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone. Monitor patients for signs of diminished diuresis and/or effects on blood pressure and increase the dosage of the diuretic as needed. 7.10 Anticholinergic Drugs The concomitant use of anticholinergic drugs with TUXARIN ER may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus [ see Warnings and Precautions (5.10) ]. Monitor patients for signs of urinary retention or reduced gastric motility when TUXARIN ER is used concomitantly with anticholinergic drugs. Additive adverse effects resulting from cholinergic blockade (e.g., xerostomia, blurred vision, or constipation) may occur when anticholinergic drugs are administered with chlorpheniramine .

ADVERSE REACTIONS The following serious adverse reactions are described, or described in greater detail, in other sections: Addiction, abuse, and misuse [ see Warnings and Precautions (5.1) , Drug Abuse and Dependence (9.3) ] Life-threatening respiratory depression [ see Warnings and Precautions (5.2 , 5.3 , 5.4 , 5.5 , 5.9) , Overdosage (10) ] Ultra-rapid metabolism of codeine and other risk factors for life-threatening respiratory depression in children [ see Warnings and Precautions (5.3) ] Accidental overdose and death due to medication errors [ see Warnings and Precautions (5.6) ] Decreased mental alertness with impaired mental and/or physical abilities [ see Warnings and Precautions (5.7) ] Interactions with benzodiazepines and other CNS depressants [ see Warnings and Precautions (5.9) ] Paralytic ileus, gastrointestinal adverse reactions [ see Warnings and Precautions (5.10) ] Increased intracranial pressure [ see Warnings and Precautions (5.11) ] Obscured clinical course in patients with head injuries [ see Warnings and Precautions (5.11) ] Seizures [ see Warnings and Precautions (5.12) ] Interactions with MAOI [ see Warnings and Precautions (5.13) ] Severe hypotension [ see Warnings and Precautions (5.14) ] Neonatal Opioid Withdrawal Syndrome [ see Warnings and Precautions (5.15) ] Adrenal insufficiency [ see Warnings and Precautions (5.16) ] The following adverse reactions have been identified during clinical studies, or during post-approval use of codeine and/or chlorpheniramine. Because these reactions may be reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. The most common adverse reactions to TUXARIN ER include: Sedation (somnolence, mental clouding, lethargy), impaired mental and physical performance, lightheadedness, dizziness, headache, dry mouth, nausea, vomiting, constipation, shortness of breath, and sweating. Other reactions include: Anaphylaxis : Anaphylaxis has been reported with codeine, one of the ingredients in TUXARIN ER. Body as a whole : Coma, death, fatigue, falling injuries, lethargy. Cardiovascular : Peripheral edema, increased blood pressure, decreased blood pressure, tachycardia, chest pain, palpitation, syncope, orthostatic hypotension, prolonged QT interval, hot flush. Central Nervous System : Ataxia, facial dyskinesia, insomnia, increased intracranial pressure, migraine, seizure, tremor, tinnitus, vertigo. Dermatologic : Flushing, hyperhidrosis, pruritus, rash. Endocrine/Metabolic : Cases of serotonin syndrome, a potentially life-threatening condition, have been reported during concomitant use of opioids with serotonergic drugs. Cases of adrenal insufficiency have been reported with opioid use, more often following greater than one month of use. Cases of androgen deficiency have occurred with chronic use of opioids [ see Clinical Pharmacology (12.2) ]. Gastrointestinal : Abdominal pain, bowel obstruction, decreased appetite, diarrhea, difficulty swallowing, GERD, indigestion, pancreatitis, paralytic ileus, biliary tract spasm (spasm of the sphincter of Oddi). Genitourinary : Urinary tract infection, ureteral spasm, spasm of vesicle sphincters, urinary retention. Hematologic : Agranulocytosis, aplastic anemia, and thrombocytopenia have been reported. Laboratory: Increases in serum amylase. Musculoskeletal : Arthralgia, backache, muscle spasm. Ophthalmic : Blurred vision, diplopia, miosis (constricted pupils), visual disturbances. Psychiatric : Agitation, anxiety, confusion, fear, dysphoria, depression, hallucinations. Reproductive : Hypogonadism, infertility. Respiratory : Bronchitis, cough, dry nose, dry throat, dyspnea, nasal congestion, nasopharyngitis, respiratory depression, sinusitis, thickening of bronchial secretions, tightness of chest and wheezing, upper respiratory tract infection. Other : Drug abuse, drug dependence, opioid withdrawal syndrome. Hypoglycemia: Cases of hypoglycemia have been reported in patients taking opioids. Most reports were in patients with at least one predisposing risk factor (e.g., diabetes). Common adverse reactions of TUXARIN ER include: Sedation (somnolence, mental clouding, lethargy), impaired mental and physical performance, lightheadedness, dizziness, headache, dry mouth, nausea, vomiting, constipation, shortness of breath, and sweating. ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact MainPointe Pharmaceuticals, LLC at 502-709-7544 or go to mainpointepharmaceuticals.com or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

Mechanism of Action Codeine Codeine is an opioid agonist relatively selective for the mu-opioid receptor, but with a much weaker affinity than morphine. The analgesic and antitussive properties of codeine have been speculated to come from its conversion to morphine. The precise mechanism of action of codeine and other opiates is not known; however, codeine is believed to act centrally on the cough center. In excessive doses, codeine will depress respiration. Chlorpheniramine Chlorpheniramine is a propylamine derivative antihistamine (H 1 -receptor antagonist) of the alkylamine class that also possesses anticholinergic and sedative activity. It prevents released histamine from dilating capillaries and causing edema of the respiratory mucosa.