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Codeine Sulfate Tablets

DEA Controlled Substance Schedule C-II

TABLE OF CONTENTS

1. DESCRIPTION 8. ADVERSE REACTIONS
2. INDICATIONS AND USAGE 9. DRUG ABUSE AND DEPENDENCE
3. DOSAGE AND ADMINISTRATION 10. OVERDOSAGE
4. CONTRAINDICATIONS 11. DRUG INTERACTIONS
5. MECHANISM OF ACTION 12. PHARMACOKINETICS
6. USE IN SPECIFIC POPULATIONS 13. HOW SUPPLIED/STORAGE AND HANDLING
7. WARNINGS AND PRECAUTIONS  

 

1. DESCRIPTION

Codeine sulfate is an opioid analgesic, related to morphine, but with less potent analgesic properties.

Chemically, codeine is Morphinan-6-ol,7,8-didehydro-4,5-epoxy-3-methoxy-17-methyl-(5α,6α)-, sulfate (2:1) (salt), trihydrate. Its empirical formula is C18H21NO3 and its molecular weight is 299.36.

Its structure is as follows:

Each tablet contains 15, 30, or 60 mg of codeine sulfate and the following inactive ingredients: colloidal silicon dioxide, microcrystalline cellulose, pregelatinized starch, and stearic acid.

2. INDICATIONS AND USAGE

Codeine sulfate is an opioid analgesic indicated for the relief of mild to moderately severe pain where the use of an opioid analgesic is appropriate.

3. DOSAGE AND ADMINISTRATION

Selection of patients for treatment with codeine sulfate should be governed by the same principles that apply to the use of similar opioid analgesics. Physicians should individualize treatment in every case, using non-opioid analgesics, opioids on an as needed basis and/or combination products, and chronic opioid therapy in a progressive plan of pain management.

3.1 Individualization of Dosage

As with any opioid drug product, adjust the dosing regimen for each patient individually, taking into account the patient's prior analgesic treatment experience. In the selection of the initial dose of codeine sulfate, attention should be given to the following:

The following dosing recommendations, therefore, can only be considered suggested approaches to what is actually a series of clinical decisions over time in the management of the pain of each individual patient.

Continual re-evaluation of the patient receiving codeine sulfate is important, with special attention to the maintenance of pain control and the relative incidence of side effects associated with therapy. During chronic therapy, especially for noncancer-related pain, the continued need for the use of opioid analgesics should be re-assessed as appropriate.

During periods of changing analgesic requirements, including initial titration, frequent contact is recommended between physician, other members of the healthcare team, the patient, and the caregiver/family.

3.2 Initiation of Therapy

The usual adult dosage is 15 mg to 60 mg repeated up to every four hours as needed for pain. The maximum 24 hour dose is 360 mg.

Titrate the dose based upon the individual patient’s response to their initial dose of codeine. Adjust the dose to an acceptable level of analgesia taking into account the improvement in pain intensity and the tolerability of the codeine by the patient.

It should be kept in mind, however, that tolerance to codeine sulfate can develop with continued use and that the incidence of untoward effects is dose-related. Adult doses of codeine higher than 60 mg fail to give commensurate relief of pain and are associated with an appreciably increased incidence of undesirable side effects.

3.3 Cessation of Therapy

When the patient no longer requires therapy with codeine sulfate, gradually taper the dose to prevent signs and symptoms of withdrawal in the physically dependent patient.

4. CONTRAINDICATIONS

Codeine sulfate is contraindicated in patients with known hypersensitivity to codeine or any components of the product. Persons known to be hypersensitive to certain other opioids may exhibit cross-sensitivity to codeine.

Codeine sulfate is contraindicated in patients with respiratory depression in the absence of resuscitative equipment.

Codeine sulfate is contraindicated in patients with acute or severe bronchial asthma or hypercarbia.

Codeine sulfate is contraindicated in any patient who has or is suspected of having paralytic ileus.

5. MECHANISM OF ACTION

Codeine sulfate is an opioid analgesic, related to morphine, but with less potent analgesic properties. Codeine is selective for the mu receptor, but with a much weaker affinity than morphine. The analgesic properties of codeine have been speculated to come from its conversion to morphine, although the exact mechanism of analgesic action remains unknown.

Effects of the Central Nervous System (CNS)

The principal therapeutic action of codeine sulfate is analgesia. Although the precise mechanism of the analgesic action is unknown, specific CNS opiate receptors and endogenous compounds with morphine-like activity have been identified throughout the brain and spinal cord and are likely to play a role in the expression and perception of analgesic effects. Some other CNS effects of codeine include anxiolysis, euphoria, and feelings of relaxation. codeine sulfate causes respiratory depression, in part by a direct effect on the brainstem respiratory centers. Codeine sulfate and other related opioids depress the cough reflex by direct effect on the cough center in the medulla. Codeine sulfate may also cause miosis.

Effects on the Gastrointestinal Tract and on Other Smooth Muscle

Gastric, biliary and pancreatic secrets may be decreased by codeine. Codeine also causes a reduction in motility and are associated with an increase in tone in the antrum of the stomach and duodenum. Digestion of food in the small intestine is delayed and propulsive contractions are decreased. Propulsive peristaltic waves in the colon are decreased, while tone is increased to the point of spasm. The end result may be constipation. Codeine can cause a marked increase in biliary tract pressure as a result of the spasm of the sphincter of Oddi. Codeine may also cause spasms of the sphincter of the urinary bladder.

Effects on the Cardiovascular System

Codeine produces peripheral vasodilation which may result in orthostatic hypotension and fainting. Release of histamine can occur, which may play a role in opioid-induced hypotension. Manifestations of histamine release and/or peripheral vasodilation may include pruritus, flushing, red eyes and sweating.

Endocrine System

Opioid agonists such as codeine sulfate have been shown to have a variety of effects on the secretion of hormones.

Opioids inhibit the secretion of ACTH, cortisol, and luteinizing hormone (LH) in humans. They also stimulate prolactin, growth hormone (GH) secretion, and pancreatic secretion of insulin and glucagons in humans and other species, rats and dogs. Thyroid stimulating hormone (TSH) has been shown to be both inhibited and stimulated by opioids.

Immune System

Codeine has been shown to have a variety of effects on components of the immune system in in vitro and animal models. The clinical significance of these findings is unknown.

6. USE IN SPECIFIC POPULATIONS

6.1 Usage in Pregnancy

Pregnancy Category C

There are no adequate and well-controlled studies in pregnant women. Codeine should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Codeine has been shown to have embryolethal and fetotoxic effects (reduced fetal body weights and delayed or incomplete ossification) in the hamster, rat and mouse models at approximately 2-4 times the maximum recommended human dose of 360 mg/day based on a body surface area comparison. Maternally toxic doses that were approximately 7 times the maximum recommended human dose of 360 mg/day, were associated with evidence of resorptions and incomplete ossification, including meningioencephalocele and cranioschisis. In contrast, codeine did not demonstrate evidence of embrytoxicity or fetotoxicity in the rabbit model at doses up to 2 times the maximum recommended human dose of 360 mg/day based on a body surface area comparison.

Nonteratogenic Effects

Neonatal codeine withdrawal has occurred in infants born to addicted and non-addicted mothers who had been taking codeine-containing medications in the days prior to delivery. Typical symptoms of narcotic withdrawal include irritability, excessive crying, tremors, hyperreflexia, seizures, fever, vomiting, diarrhea, and poor feeding. These signs occur shortly after birth and may require specific treatment.

Codeine (30 mg/kg) administered subcutaneously to pregnant rats during pregnancy and for 25 days after delivery increased neonatal mortality at birth. This dose is 0.8 times the maximum recommended human dose of 360 mg/day on a body surface area comparison.

6.2 Labor And Delivery

Opioid analgesics cross the placental barrier and may produce respiratory depression and psycho-physiologic effects in neonates. Occasionally, opioid analgesics may prolong labor through actions which temporarily reduce the strength, duration and frequency of uterine contractions. However this effect is not consistent and may be offset by an increased rate of cervical dilatation, which tends to shorten labor. The closer to delivery and the larger the dose used, the greater the possibility of respiratory depression in the newborn. Opioid analgesics should be avoided during labor if delivery of a premature infant is anticipated. If the mother has received narcotic analgesics during labor, newborn infants should be observed closely for signs of respiratory depression. Resuscitation may be required. [see Overdosage]. A specific opioid antagonist, such as naloxone or nalmefene, should be available for reversal of opioid-induced respiratory depression in the neonate.

6.3 Nursing Mothers

Codeine is secreted into human milk. In women with normal codeine metabolism (normal CYP2D6 activity), the amount of codeine secreted into human milk is low and dose-dependent. However, some women are ultra-rapid metabolizers of codeine. These women achieve higher-than-expected serum levels of codeine's active metabolite, morphine, leading to higher-than-expected levels of morphine in breast milk and potentially dangerously high serum morphine levels in their breastfed infants. Therefore, maternal use of codeine can potentially lead to serious adverse reactions, including death, in nursing infants.

The prevalence of this CYP2D6 phenotype varies widely and has been estimated at 0.5 to 1% in Chinese and Japanese, 0.5 to 1% in Hispanics, 1 to 10% in Caucasians, 3% in African Americans, and 16 to 28% in North Africans, Ethiopians, and Arabs. Data are not available for other ethnic groups.

The risk of infant exposure to codeine and morphine through breast milk should be weighed against the benefits of breastfeeding for both the mother and the baby. Caution should be exercised when codeine is administered to a nursing woman. If a codeine containing product is selected, the lowest dose should be prescribed for the shortest period of time to achieve the desired clinical effect. Mothers using codeine should be informed about when to seek immediate medical care and how to identify the signs and symptoms of neonatal toxicity, such as drowsiness or sedation, difficulty breastfeeding, breathing difficulties, and decreased tone, in their baby. Nursing mothers who are ultra-rapid metabolizers may also experience overdose symptoms such as extreme sleepiness, confusion, or shallow breathing. Prescribers should closely monitor mother-infant pairs and notify treating pediatricians about the use of codeine during breastfeeding. [see Warnings and Precautions].

6.4 Pediatric Use

The safety and effectiveness and the pharmacokinetics of codeine sulfate in pediatric patients below the age of 18 have not been established. FDA has not required pediatric studies in ages birth to one month because there is evidence strongly suggesting that codeine would be ineffective in this pediatric group since the metabolic pathways to metabolize codeine are not mature.

6.5 Geriatric Use

Codeine may cause confusion and over-sedation in the elderly. In general, dose selection for an elderly patient should be cautious, 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.

6.6 Renal Impairment

Codeine pharmacokinetics may be altered in patients with renal failure. Clearance may be decreased and the metabolites may accumulate to much higher plasma levels in patients with renal failure as compared to patients with normal renal function. Start these patients cautiously with lower doses of codeine sulfate or with longer dosing intervals and titrate slowly while carefully monitoring for side effects.

6.7 Hepatic Impairment

No formal studies have been conducted in patients with hepatic impairment so the pharmacokinetics of codeine in this patient population are unknown. Start these patients cautiously with lower doses of codeine sulfate or with longer dosing intervals and titrate slowly while carefully monitoring for side effects.

7. WARNINGS AND PRECAUTIONS

7.1 Respiratory Depression

Respiratory depression is the primary risk of codeine sulfate. Respiratory depression occurs more frequently in elderly or debilitated patients and in those suffering from conditions accompanied by hypoxia, hypercapnia, or upper airway obstruction, in whom even moderate therapeutic doses may significantly decrease pulmonary ventilation. Codeine produces dose-related respiratory depression.

Caution should be exercised when codeine sulfate is used postoperatively, in patients with pulmonary disease or shortness of breath, or whenever ventilatory function is depressed. Opioid related respiratory depression occurs more frequently in elderly or debilitated patients and in those suffering from conditions accompanies by hypoxia, hypercapnia, or upper airway obstruction, in whom even moderate therapeutic doses may significantly decrease pulmonary ventilation. Opioids, including codeine sulfate, should be used with extreme caution in patients with chronic obstructive pulmonary disease or cor pulmonale and in patients having a substantially decreased respiratory reserve (e.g., severe kyphoscoliosis), hypoxia, hypercapnia, or pre-existing respiratory depression. In such patients, even usual therapeutic doses of codeine sulfate may increase airway resistance and decrease respiratory drive to the point of apnea. Alternative non-opioid analgesics should be considered, and codeine sulfate should be employed only under careful medical supervision at the lowest effective dose in such patients. [see Overdosage].

7.2 Misuse and Abuse of Opioids

Codeine sulfate is an opioid agonist of the morphine-type and a Schedule II controlled substance. Such drugs are sought by drug abusers and people with addiction disorders. Diversion of Schedule II products is an act subject to criminal penalty.

Codeine can be abused in a manner similar to other opioid agonists, legal or illicit. This should be considered when prescribing or dispensing codeine sulfate in situations where the physician or pharmacist is concerned about an increased risk of misuse, abuse, or diversion.

Misuse and abuse of codeine sulfate poses a significant risk to the abuser that could result in overdose and death. Codeine may be abused by crushing, chewing, snorting or injecting the product. [see Drug Abuse and Dependence].

7.3 Interaction with Alcohol and Drugs of Abuse

Codeine sulfate may be expected to have additive effects when used in conjunction with alcohol, other opioids, or illicit drugs that cause central nervous system depression, because respiratory depression, hypotension, profound sedation, coma or death may result.

7.4 Head Injury and Increased Intracranial Pressure

Respiratory depressant effects of opioids and their capacity to elevate cerebrospinal fluid pressure resulting from vasodilation following CO2 retention may be markedly exaggerated in the presence of head injury, other intracranial lesions or a pre-existing increase in intracranial pressure. Furthermore, opioids including codeine sulfate, produce adverse reactions which may obscure the clinical course of patients with head injuries.

7.5 Hypotensive Effect

Codeine sulfate may cause severe hypotension in an individual whose ability to maintain blood pressure has already been compromised by a depleted blood volume or concurrent administration of drugs such as phenothiazines or general anesthetics. Codeine sulfate may produce orthostatic hypotension and syncope in ambulatory patients.

Codeine sulfate should be administered with caution to patients in circulatory shock, as vasodilation produced by the drug may further reduce cardiac output and blood pressure.

7.6 Gastrointestinal Effects

Codeine sulfate should not be administered to patients with gastrointestinal obstruction, especially paralytic ileus because codeine sulfate diminishes propulsive peristaltic waves in the gastrointestinal tract and may prolong the obstruction.

Chronic use of opioids, including codeine sulfate, may result in obstructive bowel disease especially in patients with underlying intestinal motility disorder. Codeine sulfate may cause or aggravate constipation.

Administration of codeine sulfate may obscure the diagnosis or clinical course of patients with acute abdominal conditions.

7.7 Use in Pancreatic/Biliary Tract Disease

Codeine sulfate should be used in caution in patients with biliary tract disease, including acute pancreatitis, as codeine sulfate may cause spasm of the Sphincter of Oddi and diminish biliary and pancreatic secretions.

7.8 Special Risk Patients

As with other opioids, codeine sulfate should be used with caution in elderly or debilitated patients and those with severe impairment of hepatic or renal function, hypothyrodism, Addison’s disease, prostatic hypertrophy or urethral stricture. [see Use in Specific Populations] The usual precautions should be observed and the possibility of respiratory depression should be kept in mind.

Caution should be exercised in the administration of codeine sulfate to patients with CNS depression, acute alcoholism and delirium tremens.

All opioids may aggravate convulsions in patients with convulsive disorders, and all opioids may induce or aggravate seizures in some clinical settings.

7.9 Ultra-Rapid Metabolizers of Codeine

Some individuals may be ultra-rapid metabolizers due to a specific CYP2D6*2x2 genotype. 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 experience overdose symptoms such as extreme sleepiness, confusion, or shallow breathing.

The prevalence of this CYP2D6 phenotype varies widely and has been estimated at 0.5 to 1% in Chinese and Japanese, 0.5% to 1% in Hispanics, 1 to 10% in Caucasians, 3% in African Americans, and 16 to 28% in North Africans, Ethiopians, and Arabs. Data are not available for other ethnic groups.

When physicians prescribe codeine-containing drugs, they should choose the lowest effective dose for the shortest period of time and inform their patients about these risks and the signs of morphine overdose. [see Use in Specific Populations].

7.10 Driving and Operating Machinery

Patients should be cautioned that codeine sulfate could impair the mental and/or physical abilities needed to perform potentially hazardous activities such as driving a car or operating machinery.

Patients should also be cautioned about the potential combined effects of codeine sulfate with other CNS depressants, including opioids, phenothiazines, sedative/hypnotics and alcohol. [see Drug Interactions].

8. ADVERSE REACTIONS

Serious adverse reactions associated with codeine are respiratory depression and, to a lesser degree, circulatory depression, respiratory arrest, shock, and cardiac arrest.

The most frequently observed adverse reactions with codeine administration include drowsiness, lightheadedness, dizziness, sedation, shortness of breath, nausea, vomiting, sweating , and constipation.

Other adverse reactions include allergic reactions, euphoria, dysphoria, abdominal pain, and pruritis.

Other less frequently observed adverse reactions expected from opioid analgesics including codeine sulfate include:

Cardiovascular system: faintness, flushing, hypotension, palpitations, syncope.

Digestive System: abdominal cramps, anorexia, diarrhea, dry mouth, gastrointestinal distress, pancreatitis

Nervous system: anxiety, drowsiness, fatigue, headache, insomnia, nervousness, shakiness, somnolence, vertigo, visual
disturbances, weakness.

Skin and Appendages: rash, sweating, urticaria.

9. DRUG ABUSE AND DEPENDENCE

9.1 Controlled Substance

Codeine sulfate is an opioid agonist and is a Schedule II controlled substance. Codeine sulfate can be abused and is subject to criminal diversion.

9.2 Abuse

Drug addiction is characterized by compulsive use, use for non-medical purposes, and continued use despite harm or risk of harm. Drug addiction is a treatable disease, utilizing a multi-disciplinary approach, but relapse is common.

“Drug seeking” behavior is very common in addicts and drug abusers. Drug-seeking tactics include emergency calls or visits near the end of office hours, refusal to undergo appropriate examination, testing or referral, repeated “loss” of prescriptions, tampering with prescriptions and reluctance to provide prior medical records or contact information for other treating physician(s). “Doctor shopping” to obtain additional prescriptions is common among drug abusers and people suffering from untreated addiction.

Abuse and addiction are separate and distinct from physical dependence and tolerance. Physicians should be aware that addiction may not be accompanied by concurrent tolerance and symptoms of physical dependence. The converse is also true. In addition, abuse of opioids can occur in the absence of true addiction and is characterized by misuse for nonmedical purposes, often in combination with other psychoactive substances. Careful record-keeping of prescribing information, including quantity, frequency, and renewal requests is strongly advised.

Codeine is intended for oral use only. Abuse of codeine poses a risk of overdose and death. The risk is increased with concurrent abuse of alcohol and other substances. Parenteral drug abuse is commonly associated with transmission of infectious diseases such as hepatitis and HIV.

Proper assessment of the patient, proper prescribing practices, periodic re-evaluation of therapy, and proper dispensing and storage are appropriate measures that help to limit abuse of opioid drugs.

Infants born to mothers physically dependent on opioids will also be physically dependent and may exhibit respiratory difficulties and withdrawal symptoms. [see Use in Specific Populations].

9.3 Dependence

Tolerance is the need for increasing doses of opioids to maintain a defined effect such as analgesia (in the absence of disease progression or other external factors). Physical dependence is manifested by withdrawal symptoms after abrupt discontinuation of a drug or upon administration of an antagonist. Physical dependence and tolerance are not unusual during chronic opioid therapy.

The opioid abstinence or withdrawal syndrome is characterized by some or all of the following: restlessness, lacrimation, rhinorrhea, yawning, perspiration, chills, myalgia, and mydriasis. Other symptoms also may develop, including irritability, anxiety, backache, joint pain, weakness, abdominal cramps, insomnia, nausea, anorexia, vomiting, diarrhea, or increased blood pressure, respiratory rate, or heart rate.

In general, opioids should not be abruptly discontinued.

10. OVERDOSAGE

Symptoms

Acute overdose of codeine is characterized by respiratory depression (a decrease in respiratory rate and/or tidal volume, Cheyne-Stokes respiration, cyanosis), extreme somnolence progressing to stupor or coma, miosis (mydriasis may occur in terminal narcosis or severe hypoxia), skeletal muscle flaccidity, cold and clammy skin, and sometimes bradycardia and hypotension. In severe overdosage, apnea, circulatory collapse, cardiac arrest and death may occur.

Codeine sulfate may cause miosis, even in total darkness. Pinpoint pupils are a sign of opioid overdose but are not pathognomonic (e.g., pontine lesions of hemorrhagic or ischemic origin may produce similar findings). Marked mydriasis rather than miosis may be seen with hypoxia in overdose situations.

Treatment

Primary attention should be given to the re-establishment of adequate respiratory exchange through provision of a patent airway and institution of assisted or controlled ventilation as necessary. Supportive measures (including oxygen and vasopressors) should be employed in the management of circulatory shock and pulmonary edema accompanying overdose as indicated. Cardiac arrest or arrhythmias may require cardiac massage or defibrillation. Induction of emesis is not recommended because of the potential for CNS depression and seizures. Activated charcoal is recommended if the patient is awake and able to protect his/her airway. In persons who are at risk for abrupt onset of seizures or mental status depression, activated charcoal should be administered by medical or paramedical personnel capable of airway management to prevent aspiration in the event of spontaneous emesis. Severe agitation or seizures should be treated with an intravenous benzodiazepine.

The opioid antagonist naloxone hydrochloride is a specific antidote against respiratory depression resulting from overdosage or unusual sensitivity to opiate agonists, including codeine. Therefore, an appropriate dose of naloxone hydrochloride (see prescribing information for naloxone hydrochloride) should be administered, preferably by the intravenous route, simultaneously with efforts at respiratory resuscitation. Since the duration of action of codeine may exceed that of the antagonist, the patient should be kept under continued surveillance and repeated doses of the antagonist should be administered as needed to maintain adequate respiration. A narcotic antagonist should not be administered in the absence of clinically significant respiratory or cardiovascular depression secondary to codeine sulfate overdose.

In an individual physically dependent on opioids, administration of the usual dose of the antagonist will precipitate an acute withdrawal syndrome. The severity of the withdrawal symptoms experienced will depend on the degree of physical dependence and the dose of the antagonist administered. Use of an opioid antagonist should be reserved for cases where such treatment is clearly needed. If it is necessary to treat serious respiratory depression in the physically dependent patient, administration of the antagonist should be initiated with care and titrated with smaller than usual doses.

11. DRUG INTERACTIONS

11.1 CNS Depressants

Concurrent use of other opioids, antihistamines, antipsychotics, antianxiety agents, or other CNS depressants (including sedatives, hypnotics, general anesthetics, antiemetics, phenothiazines, or other tranquilizers or alcohol) concomitantly with codeine sulfate tablets may result in additive CNS depression, respiratory depression, hypotension, profound sedation, or coma. Use codeine sulfate with caution and in reduced dosages in patients taking these agents.

11.2 Mixed Agonist/Antagonist Opioid Analgesics

Mixed agonist/antagonist analgesics (i.e., pentazocine, nalbuphine, and butorphanol) should NOT be administered to patients who have received or are receiving a course of therapy with a pure opioid agonist analgesic such as codeine sulfate. In these patients, mixed agonist/antagonist analgesics may reduce the analgesic effect and/or may precipitate withdrawal symptoms.

11.3 Anticholinergics

Anticholinergics or other medications with anticholinergic activity when used concurrently with opioids analgesics including codeine sulfate, may result in increased risk of urinary retention and/or severe constipation, which may lead to paralytic ileus.

11.4 Antidepressants

Use of MAO inhibitors or tricyclic antidepressants with codeine sulfate may increase the effect of either the antidepressant or codeine. MAOIs markedly potentiate the action of morphine sulfate, the major metabolite of codeine. Codeine should not be used in patients taking MAOIs or within 14 days of stopping such treatment.

11.5 Metabolic Enzymes

Patients taking cytochrome P-450 enzyme inducers or inhibitors may demonstrate an altered response to codeine, therefore analgesic activity should be monitored. Codeine sulfate is metabolized by the cytochrome P-450 3A4 and 2D6 isoenzymes. The concurrent use of drugs that preferentially induce codeine Ndemethylation (cytochrome P-450 3A4) may increase the plasma concentrations of codeine’s inactive metabolite norcodeine. Drugs that are strong inhibitors of codeine O-demethylation (cytochrome P-450 2D6) may decrease the plasma concentrations of codeine’s active metabolites, morphine and morphine-6-glucuronide. The contribution of these active metabolites to the overall analgesic effect of codeine is not fully understood, but should be considered.

11.6 Drug-Laboratory Test Interaction

Codeine sulfate tablets may cause an elevation of plasma amylase and lipase due to the potential of codeine to produce spasm of the sphincter of Oddi. Determination of these enzyme levels may be unreliable for some time after an opiate agonist has been given.

12. PHARMACOKINETICS

Absorption

Codeine is absorbed from the gastrointestinal tract with maximum plasma concentration occurring 60 minutes post administration.

Food Effects

When 60 mg codeine sulfate was administered 30 minutes after ingesting a high fat/high calorie meal, there was no significant change in the rate and extent of absorption of codeine.

Steady-state

Administration of 15 mg codeine sulfate every four hours for 5 days resulted in steady-state concentrations of codeine, morphine, morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G) within 48 hours.

Distribution

Codeine has been reported to have an apparent volume of distribution of approximately 3-6 L/kg, indicating extensive distribution of the drug into tissues. Codeine has low plasma protein binding with about 7-25% of codeine bound to plasma proteins.

Metabolism

About 70-80% of administered dose of codeine is metabolized by conjugation with glucuronic acid to codeine-6glucuronide (C6G) and via O-demethylation to morphine (about 5-10%) and N-demethylation to norcodeine (about 10%) respectively. UDP-glucuronosyltransferase (UGT) 2B7 and 2B4 are the major enzymes mediating glucurodination of codeine to C6G. Cytochrome P450 2D6 is the major enzyme responsible for conversion of codeine to morphine and P450 3A4 is the major enzyme mediating conversion of codeine to norcodeine. Morphine and norcodeine are further metabolized by conjugation with glucuronic acid. The glucuronide metabolites of morphine are morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M6G). Morphine and M6G are known to have analgesic activity in humans. The analgesic activity of C6G in humans is unknown. Norcodeine and M3G are generally not considered to possess analgesic properties.

Elimination

Approximately 90% of the total dose of codeine is excreted through the kidneys, of which approximately 10% is unchanged codeine. Plasma half-lives of codeine and its metabolites have been reported to be approximately 3 hours.

13. HOW SUPPLIED/STORAGE AND HANDLING

1) How Available:

a) Brand name: CODEINE SULFATE, by Roxane.

b) Generic drugs: None.

2) How Supplied:

Codeine Sulfate Tablets (by ROXANE LABS):

15 mg Tablet: white, biconvex tablets scored on one side, with strength-indicating number "15" debossed on the scored side and product identification number "54 613" debossed on the other side.

Unit dose, 25 tablets per blister card

NDC 0054-8155-24: 4 Cards per Carton

30 mg Tablet: white, biconvex tablets scored on one side, with strength-indicating number "30" debossed on the scored side and product identification number "54 783" debossed on the other side.

Unit dose, 25 tablets per blister card, NDC 0054-4156-24: 4 Cards per Carton

NDC 0054-0244-25: Bottles of 100 Tablets

60 mg Tablet: white, biconvex tablets scored on one side, with strength-indicating number "60" debossed on the scored side and product identification number "54 412" debossed on the other side.

NDC 0054-4157-25: Bottles of 100 Tablets

3) Storage:

Store at Controlled Room Temperature, 15° to 30°C (59° to 86°F). Protect from light and moisture.

Dispense in well-closed container as defined in the USP/NF.

Blisters are not child-resistant. Use child-resistant closure if dispensing to outpatient.

All opioids are liable to diversion and misuse both by the general public and healthcare workers and should be handled accordingly.

Rx only

Rev 04/12