Acetaminophen And Codeine Phosphate - Acetaminophen And Codeine Phosphate solution prescribing information
WARNING: SERIOUS AND LIFE-THREATENING RISKS FROM USE OFACETAMINOPHEN AND CODEINE PHOSPHATE ORAL SOLUTION
Risk of Medication Errors
Ensure accuracy when prescribing, dispensing, and administering acetaminophen and codeine phosphate oral solution, 120 mg/12 mg per 5 mL. Dosing errors due to confusion between mg and mL, and other codeine containing oral products of different concentrations can result in accidental overdose and death [see WARNINGS , DOSAGE AND ADMINISTRATION ].
Addiction, Abuse, and Misuse
Because the use of acetaminophen and codeine phosphate oral solution exposes patients and other users to the risks of opioid addiction, abuse, and misuse, which can lead to overdose and death, assess each patient’s risk prior to prescribing and reassess all patients regularly for the development of these behaviors and conditions [see WARNINGS ].
Life-Threatening Respiratory Depression
Serious, life-threatening, or fatal respiratory depression may occur with use of acetaminophen and codeine phosphate oral solution, especially during initiation or following a dose increase. To reduce the risk of respiratory depression, proper dosing and titration of acetaminophen and codeine phosphate oral solution are essential [see WARNINGS ].
Accidental Ingestion
Accidental ingestion of even one dose of acetaminophen and codeine phosphate oral solution, especially by children, can result in a fatal overdose of acetaminophen and codeine [see WARNINGS ].
Risks From Concomitant Use With Benzodiazepines Or Other CNS Depressants
Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of acetaminophen and codeine phosphate oral solution and benzodiazepines or other CNS depressants for use in patients for whom alternative treatment options are inadequate [see WARNINGS; Drug Interactions ].
Neonatal Opioid Withdrawal Syndrome
If opioid use is required for an extended period of time in a pregnant woman, advise the patient of the risk of NOWS, which may be life-threatening if not recognized and treated. Ensure that management by neonatology experts will be available at delivery [see WARNINGS ].
Opioid Analgesic Risk Evaluation and Mitigation Strategy (REMS)
Healthcare providers are strongly encouraged to complete a REMS-compliant education program and to counsel patients and caregivers on serious risks, safe use, and the importance of reading the Medication Guide with each prescription [see WARNINGS ].
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. Most of the reported cases occurred following tonsillectomy and/or adenoidectomy, and many of the children had evidence of being an ultra-rapid metabolizer of codeine due to a CYP2D6 polymorphism [see WARNINGS ]. Acetaminophen and codeine phosphate oral solution is contraindicated in children younger than 12 years of age and in children younger than 18 years of age following tonsillectomy and/or adenoidectomy [see CONTRAINDICATIONS ]. Avoid the use of acetaminophen and codeine phosphate oral solution 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.
Interactions with Drugs Affecting Cytochrome P450 Isoenzymes
The effects of concomitant use or discontinuation of cytochrome P450 3A4 inducers, 3A4 inhibitors, or 2D6 inhibitors with codeine are complex. Use of cytochrome P450 3A4 inducers, 3A4 inhibitors, or 2D6 inhibitors with acetaminophen and codeine phosphate oral solution requires careful consideration of the effects on the parent drug, codeine, and the active metabolite, morphine [see WARNINGS ; DRUG INTERACTIONS ].
Hepatotoxicity
Acetaminophen has been associated with cases of acute liver failure, at times resulting in liver transplant and death. Most of the cases of liver injury are associated with the use of acetaminophen at doses that exceed 4,000 milligrams per day, and often involve more than one acetaminophen-containing product [see WARNINGS ].
INDICATIONS AND USAGE
Acetaminophen and codeine phosphate oral solution is indicated for the management of mild to moderate pain where treatment with an opioid is appropriate and for which alternative treatments are inadequate.
Limitations of Use
Because of the risks of addiction, abuse, and misuse, with opioids, opioids, which can occur at any dosage or duration [see WARNINGS ], reserve acetaminophen and codein phosphate oral solution for use in patients for whom alternative treatment options [e.g., non-opioid analgrsics]:
- Have not been tolerated, or are not expected to be tolerated,
- Have not provided adequate analgesia, or are not expected to provide adequate analgesia
Acetaminophen and codeine phosphate oral solution should not be used for an extended period of time unless the pain remains severe enough to require an opioid analgesic and for which alternative treatment options continue to be inadequate.
DOSAGE AND ADMINISTRATION
Important Dosage and Administration Instructions
Acetaminophen and codeine phosphate oral solution should be prescribed only by healthcare professionals who are knowledgeable about the use of opioids and how to mitigate the associated risks.
Use the lowest effective dosage for the shortest duration of time consistent with individual patient treatment goals [see WARNINGS ]. Because the risk of overdose increases as opioid doses increase, reserve titration to higher doses of acetaminophen and codeine phosphate oral solution for patients in whom lower doses are insufficiently effective and in whom the expected benefits of using a higher dose opioid clearly outweigh the substantial risks.
Many acute pain conditions (e.g., the pain that occurs with a number of surgical procedures or acute musculoskeletal injuries) require no more than a few days of an opioid analgesic. Clinical guidelines on opioid prescribing for some acute pain conditions are available.
There is variability in the opioid analgesic dose and duration needed to adequately manage pain due both to the cause of pain and to individual patient factors. Initiate the dosing regimen for each patient individually, taking into account the patient’s underlying cause and severity of pain, prior analgesic treatment and response, and risk factors for addiction, abuse, and misuse [see WARNINGS ].
Respiratory depression can occur at any time during opioid therapy, especially when initiating and following dosage increases with acetaminophen and codeine phosphate oral solution. Consider this risk when selecting an initial dose and when making dose adjustments [see WARNINGS ].
Patient Access to Naloxone for the Emergency Treatment of Opioid Overdose
Discuss the availability of naloxone for the emergency treatment of opioid overdose with the patient and caregiver and assess the potential need for access to naloxone, both when initiating and renewing treatment with acetaminophen and codeine phosphate oral solution [see WARNINGS , Life-Threatening Respiratory Depression ; PRECAUTIONS , Information for Patients/Caregivers ].
Inform patients and caregivers about the various ways to obtain naloxone as permitted by individual state naloxone dispensing and prescribing regulations (e.g., by prescription, directly from a pharmacist, or as part of a community-based program).
Consider prescribing naloxone, based on the patient’s risk factors for overdose, such as concomitant use of CNS depressants, a history of opioid use disorder, or prior opioid overdose. The presence of risk factors for overdose should not prevent the proper management of pain in any given patient [see WARNINGS , Addiction , Abuse, and Misuse, Life-Threatening Respiratory Depression , Risks from Concomitant Use with Benzodiazepines or Other CNS Depressants ].
Consider prescribing naloxone when the patient has household members (including children) or other close contacts at risk for accidental ingestion or overdose .
Initial Dosage
Use of Acetaminophen and Codeine Phosphate Oral Solution as the First Opioid Analgesic
Initiate treatment with acetaminophen and codeine phosphate oral solution at a dose of 15 mL (1 tablespoonful every 4 hours as needed for pain. Titrate the dose based upon the individual patient’s response to their initial dose of acetaminophen and codeine phosphate oral solution.
Dosage should be adjusted according to severity of pain and response of the patient. However, it should be kept in mind that tolerance to codeine can develop with continued use and that the incidence of untoward effects is dose related. Adult doses of codeine higher than 60 mg are associated with an increased incidence of adverse reactions and are not associated with greater efficacy.
Acetaminophen and codeine phosphate oral solution contains 120 mg of acetaminophen and 12 mg of codeine phosphate per 5 mL (teaspoonful) and is given orally.
Adults
15 mL (1 tablespoonful) every 4 hours as needed.
Conversion from Other Opioids to Acetaminophen and Codeine Phosphate Oral Solution
There is inter-patient variability in the potency of opioid drugs and opioid formulations. Therefore, a conservative approach is advised when determining the total daily dosage of acetaminophen and codeine phosphate oral solution. It is safer to underestimate a patient’s 24-hour acetaminophen and codeine phosphate oral solution dosage than to overestimate the 24-hour acetaminophen and codeine phosphate oral solution dosage and manage an adverse reaction due to overdose.
Titration and Maintenance of Therapy
Individually titrate acetaminophen and codeine phosphate oral solution to a dose that provides adequate analgesia and minimizes adverse reactions. Continually reevaluate patients receiving acetaminophen and codeine phosphate oral solution to assess the maintenance of pain control, signs and symptoms of opioid withdrawal, and other adverse reactions, as well as reassess for the development of addiction, abuse, or misuse [see WARNINGS ]. Frequent communication is important among the prescriber, other members of the healthcare team, the patient, and the caregiver/family during periods of changing analgesic requirements, including initial titration.
If the level of pain increases after dosage stabilization, attempt to identify the source of increased pain before increasing the acetaminophen and codeine phosphate oral solution dosage. If after increasing the dosage, unacceptable opioid-related adverse reactions are observed (including an increase in pain after dosage increase), consider reducing the dosage [see WARNINGS ]. Adjust the dosage to obtain an appropriate balance between management of pain and opioid-related adverse reactions.
Safe Reduction or Discontinuation of Acetaminophen and Codeine Phosphate Oral Solution
Do not abruptly discontinue acetaminophen and codeine phosphate oral solution in patients who may be physically dependent on opioids. Rapid discontinuation of opioid analgesics in patients who are physically dependent on opioids has resulted in serious withdrawal symptoms, uncontrolled pain, and suicide. Rapid discontinuation has also been associated with attempts to find other sources of opioid analgesics, which may be confused with drug-seeking for abuse. Patients may also attempt to treat their pain or withdrawal symptoms with illicit opioids, such as heroin, and other substances.
When a decision has been made to decrease the dose or discontinue therapy in an opioid-dependent patient taking acetaminophen and codeine phosphate oral solution, there are a variety of factors that should be considered, including the total daily dose of opioid (including acetaminophen and codeine phosphate oral solution) the patient has been taking, the duration of treatment, the type of pain being treated, and the physical and psychological attributes of the patient. It is important to ensure ongoing care of the patient and to agree on an appropriate tapering schedule and follow-up plan so that patient and provider goals and expectations are clear and realistic. When opioid analgesics are being discontinued due to a suspected substance use disorder, evaluate and treat the patient, or refer for evaluation and treatment of the substance use disorder. Treatment should include evidence-based approaches, such as medication assisted treatment of opioid use disorder. Complex patients with co-morbid pain and substance use disorders may benefit from referral to a specialist.
There are no standard opioid tapering schedules that are suitable for all patients. Good clinical practice dictates a patient-specific plan to taper the dose of the opioid gradually. For patients on acetaminophen and codeine phosphate oral solution who are physically opioid-dependent, initiate the taper by a small enough increment (e.g., no greater than 10% to 25% of the total daily dose) to avoid withdrawal symptoms, and proceed with dose-lowering at an interval of every 2 to 4 weeks. Patients who have been taking opioids for briefer periods of time may tolerate a more rapid taper.
It may be necessary to provide the patient with lower dosage strengths to accomplish a successful taper. Reassess the patient frequently to manage pain and withdrawal symptoms, should they emerge. Common withdrawal symptoms include restlessness, lacrimation, rhinorrhea, yawning, perspiration, chills, myalgia, and mydriasis. Other signs and 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. If withdrawal symptoms arise, it may be necessary to pause the taper for a period of time or raise the dose of the opioid analgesic to the previous dose, and then proceed with a slower taper. In addition, monitor patients for any changes in mood, emergence of suicidal thoughts, or use of other substances.
When managing patients taking opioid analgesics, particularly those who have been treated for a long duration and/or with high doses for chronic pain, ensure that a multimodal approach to pain management, including mental health support (if needed), is in place prior to initiating an opioid analgesic taper. A multimodal approach to pain management may optimize the treatment of chronic pain, as well as assist with the successful tapering of the opioid analgesic [see WARNINGS /Withdrawal , DRUG ABUSE AND DEPENDENCE ] .
When a patient who has been taking acetaminophen and codeine phosphate oral solution regularly and may be physically dependent no longer requires therapy with acetaminophen and codeine phosphate oral solution, 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. Do not abruptly discontinue acetaminophen and codeine phosphate oral solution in a physically-dependent patient [see WARNINGS , DRUG ABUSE AND DEPENDENCE ].
CONTRAINDICATIONS
Acetaminophen and codeine phosphate oral solution is contraindicated for:
- all children younger than 12 years of age [see WARNINGS ].
- post-operative management in children younger than 18 years of age following tonsillectomy and/or adenoidectomy [see WARNINGS ].
Acetaminophen and codeine phosphate oral solution is contraindicated in patients with:
- Significant respiratory depression [see WARNINGS ].
- Acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment [see WARNINGS ].
- Concurrent use of monoamine oxidase inhibitors (MAOIs) or use of MAOIs within the last 14 days [see WARNINGS ] .
- Patients with known or suspected gastrointestinal obstruction, including paralytic ileus [see WARNINGS ].
- Patients with hypersensitivity to codeine, acetaminophen, or any of the formulation excipients (e.g., anaphylaxis) [see WARNINGS ].
ADVERSE REACTIONS
The following serious adverse reactions are described, or described in greater detail, in other sections:
- Addiction, Abuse, and Misuse [see WARNINGS ]
- Life-Threatening Respiratory Depression [see WARNINGS ]
- Ultra-Rapid Metabolism of Codeine and Other Risk Factors for Life-Threatening Respiratory Depression in Children [see WARNINGS ]
- Neonatal Opioid Withdrawal Syndrome [see WARNINGS ]
- Interactions with CNS Depressants [see WARNINGS ]
- Severe Hypotension [see WARNINGS ]
- Gastrointestinal Adverse Reactions [see WARNINGS ]
- Seizures [see WARNINGS ]
- Withdrawal [see WARNINGS ]
The following adverse reactions associated with the use of codeine were identified in postmarketing reports. Because some of these reactions were 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.
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, pruritis, rash, thrombocytopenia, and agranulocytosis.
Other less frequently observed adverse reactions expected from opioid analgesics, including acetaminophen and codeine phosphate oral solution:
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, urticarial
- Serotonin syndrome : Cases of serotonin syndrome, a potentially life-threatening condition, have been reported during concomitant use of opioids with serotonergic drugs.
- Adrenal insufficiency : Cases of adrenal insufficiency have been reported with opioid use, more often following greater than one month of use.
- Anaphylaxis : Anaphylaxis has been reported with ingredients contained in acetaminophen and codeine phosphate oral solution.
- Androgen deficienc y: Cases of androgen deficiency have occurred with chronic use of opioids [see CLINICAL PHARMACOLOGY ].
- Hyperalgesia and Allodynia : Cases of hyperalgesia and allodynia have been reported with opioid therapy of any duration [see WARNINGS ]
- 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).
To report SUSPECTED ADVERSE REACTIONS, contact PAI Pharma. at 1-800-845-8210 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
DESCRIPTION
Acetaminophen and Codeine Phosphate Oral Solution is pharmacologically classified as an analgesic.
Acetaminophen, 4'-hydroxyacetanilide, a slightly bitter, white, odorless, crystalline powder, is a non- opioid, non-salicylate analgesic and antipyretic. It has the following structural formula:
C 8 H g NO 2 N.W. 151.16
Codeine phosphate, 7,8-didehydro-4,5α-epoxy-3-methoxy-17-methylmorphinan-6α-ol phosphate (1:1) (salt) hemihydrate, a white crystalline powder, is an opioid agonist. It has the following structural formula:
 | |
| C 18 H 21 NO 3∙ H 3 PO 4∙ 1/2H 2 O | M.W. 406.37 |
Each Acetaminophen and Codeine Phosphate Oral Solution, USP 120 mg/12 mg per 5 mL, for oral administration, contains:
| Acetaminophen | 120 mg |
| Codeine Phosphate | 12 mg |
| Alcohol | 7% |
INACTIVE INGREDIENTS
FD&C Red No. 40, FD&C Yellow No. 6 (Sunset Yellow), flavoring, glycerin, propylene glycol, purified water, saccharin sodium, and sucrose.
CLINICAL PHARMACOLOGY
Mechanism of Action
Codeine is an opioid agonist relatively selective for the mu-opioid 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.
The precise mechanism of the analgesic properties of acetaminophen is not established but is thought to involve central actions.
Pharmacodynamics
Effects on the Central Nervous System
Codeine produces respiratory depression by direct action on brain stem respiratory centers. The respiratory depression involves a reduction in the responsiveness of the brain stem respiratory centers to both increases in carbon dioxide tension and electrical stimulation.
Codeine causes 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 origins may produce similar findings). Marked mydriasis rather than miosis may be seen due to hypoxia in overdose situations.
Effects on the Gastrointestinal Tract and Other Smooth Muscle
Codeine causes a reduction in motility associated with an increase in smooth muscle 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 may be increased to the point of spasm, resulting in constipation. Other opioid-induced effects may include a reduction in biliary and pancreatic secretions, spasm of sphincter of Oddi, and transient elevations in serum amylase.
Effects on the Cardiovascular System
Codeine produces peripheral vasodilation, which may result in orthostatic hypotension or syncope. Manifestations of histamine release and/or peripheral vasodilation may include pruritus, flushing, red eyes, sweating, and/or orthostatic hypotension.
Effects on the Endocrine System
Opioids inhibit the secretion of adrenocorticotropic hormone (ACTH), cortisol, and luteinizing hormone (LH) in humans [see ADVERSE REACTIONS ]. They also stimulate prolactin, growth hormone (GH) secretion, and pancreatic secretion of insulin and glucagon.
Use of opioids for an extended period of time may influence the hypothalamic-pituitary-gonadal axis, leading to androgen deficiency that may manifest as low libido, impotence, erectile dysfunction, amenorrhea, or infertility. The causal role of opioids in the clinical syndrome of hypogonadism is unknown because the various medical, physical, lifestyle, and psychological stressors that may influence gonadal hormone levels have not been adequately controlled for in studies conducted to date [see ADVERSE REACTIONS ].
Effects on the Immune System
Opioids have been shown to have a variety of effects on components of the immune system. The clinical significance of these findings is unknown. Overall, the effects of opioids appear to be modestly immunosuppressive.
Concentration–Efficacy Relationships
The minimum effective analgesic concentration will vary widely among patients, especially among patients who have been previously treated with potent agonist opioids. The minimum effective analgesic concentration of codeine for any individual patient may increase over time due to an increase in pain, the development of a new pain syndrome, and/or the development of analgesic tolerance [see DOSAGE AND ADMINISTRATION ].
Concentration–Adverse Reaction Relationships
There is a relationship between increasing codeine plasma concentration and increasing frequency of dose-related opioid adverse reactions such as nausea, vomiting, CNS effects, and respiratory depression. In opioid-tolerant patients, the situation may be altered by the development of tolerance to opioid-related adverse reactions [see DOSAGE AND ADMINISTRATION ].
Pharmacokinetics
The behavior of the individual components is described below.
Codeine
Codeine is rapidly absorbed from the gastrointestinal tract. It is rapidly distributed from the intravascular spaces to the various body tissues, with preferential uptake by parenchymatous organs such as the liver, spleen and kidney. Codeine crosses the blood-brain barrier, and is found in fetal tissue and breast milk. The plasma concentration does not correlate with brain concentration or relief of pain. Codeine is about 7-25% bound to plasma proteins and does not accumulate in body tissues.
About 70 to 80% of the administered dose of codeine is metabolized by conjugation with glucuronic acid to codeine-6-glucuronide (C6G) and via O-demethylation to morphine (about 5 to 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.
The plasma half-life is about 2.9 hours. The elimination of codeine is primarily via the kidneys, and about 90% of an oral dose is excreted by the kidneys within 24 hours of dosing. The urinary secretion products consist of free and glucuronide conjugated codeine (about 70%), free and conjugated norcodeine (about 10%), free and conjugated morphine (about 10%), normorphine (4%), and hydrocodone (1%). The remainder of the dose is excreted in the feces.
At therapeutic doses, the analgesic effect reaches a peak within 2 hours and persists between 4 and 6 hours.
Acetaminophen
Acetaminophen is rapidly absorbed from the gastrointestinal tract and is distributed throughout most body tissues. A small fraction (10-25%) of acetaminophen is bound to plasma proteins. The plasma half-life is 1.25 to 3 hours, but may be increased by liver damage and following overdosage. Elimination of acetaminophen is principally by liver metabolism and subsequent renal excretion of metabolites. Acetaminophen is primarily metabolized in the liver by first-order kinetics and involves three principal separate pathways: conjugation with glucuronide; conjugation with sulfate; and oxidation via the cytochrome, P450-dependent, mixed-function oxidase enzyme pathway to form a reactive intermediate metabolite, which conjugates with glutathione and is then further metabolized to form cysteine and mercapturic acid conjugates. The principal cytochrome P450 isoenzyme involved appears to be CYP2E1, with CYP1A2 and CYP3A4 as additional pathways.
Approximately 85% of an oral dose appears in the urine within 24 hours of administration, most as the glucuronide conjugate, with small amounts of other conjugates and unchanged drug.
See OVERDOSAGE for toxicity information.
HOW SUPPLIED
Acetaminophen and Codeine Phosphate Oral Solution USP (orange-yellow color, cherry flavor) is supplied in the following oral dosage forms:
NDC 0121-0504-04: 4 fl oz (118 mL) bottle
NDC 0121-0504-16: 16 fl oz (473 mL) bottle
NDC 0121-0504-05: 5 mL unit dose cup. Case contains 40 unit-dose cups of 5 mL (NDC 0121-0504-40), packaged in 4 trays of 10 unit-dose cups each.
NDC 0121-1008-12: 12.5 mL unit dose cup. Case contains 40 unit-dose cups of 12.5 mL (NDC 0121-1008-40), packaged in 4 trays of 10 unit-dose cups each.
Mechanism of Action
Codeine is an opioid agonist relatively selective for the mu-opioid 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.
The precise mechanism of the analgesic properties of acetaminophen is not established but is thought to involve central actions.
