Oxycodone And Aspirin - Oxycodone And Aspirin tablet prescribing information
WARNING: SERIOUS AND LIFE-THREATENING RISKS FROM USE OF OXYCODONE AND ASPIRIN TABLETS
Addiction, Abuse, and Misuse
Because the use of oxycodone and aspirin tablets 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 oxycodone and aspirin tablets, especially during initiation or following a dosage increase. To reduce the risk of respiratory depression, proper dosing and titration of oxycodone and aspirin tablets are essential (see WARNINGS ).
Accidental Ingestion
Accidental ingestion of even one dose of oxycodone and aspirin tablets, especially by children, can result in a fatal overdose of oxycodone (see WARNINGS ).
Risks From Concomitant Use With Benzodiazepines Or Other CNS Depressants
Concomitant use of opioids with benzodiazepines or central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of oxycodone and aspirin tablets and benzodiazepines or other CNS depressants for use in patients for whom alternative treatment options are inadequate [ see WARNINGS ].
Neonatal Opioid Withdrawal Syndrome (NOWS)
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 ].
Cytochrome P450 3A4 Interaction
The concomitant use of oxycodone and aspirin tablets with all cytochrome P450 3A4 inhibitors may result in an increase in oxycodone plasma concentrations, which could increase or prolong adverse reactions and may cause potentially fatal respiratory depression. In addition, discontinuation of a concomitantly used cytochrome P450 3A4 inducer may result in an increase in oxycodone plasma concentration. Regularly evaluate patients receiving oxycodone and aspirin tablets and any CYP3A4 inhibitor or inducer frequently (see CLINICAL PHARMACOLOGY , WARNINGS , PRECAUTIONS ; Drug Interactions ).
INDICATIONS AND USAGE
Oxycodone and aspirin tablets are indicated for the management of pain severe enough to require an opioid analgesic and for which alternative treatments are inadequate.
Limitations of Use
Because of the risks of addiction, abuse, and misuse, with opioids, which can occur at any dosage or duration (see WARNINGS ), reserve oxycodone and aspirin tablets for use in patients for whom alternative treatment options (e.g., non-opioid analgesics)
- Have not been tolerated, or are not expected to be tolerated,
- Have not provided adequate analgesia, or are not expected to provide adequate analgesia
Oxycodone and Aspirin tablets 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
Oxycodone and aspirin tablets 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 oxycodone and aspirin tablets 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 oxycodone and aspirin tablets. 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 oxycodone and aspirin tablets [see WARNINGS , 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
Initiating Treatment with Oxycodone and Aspirin Tablets
Initiate treatment with one tablet every 6 hours as needed for pain, and at lowest dose necessary to achieve adequate analgesia. Titrate the dose based upon the individual patient’s response to their initial dose of oxycodone and aspirin tablets. The maximum daily dose of aspirin should not exceed 4 grams or 12 tablets.
Titration and Maintenance of Therapy
Individually titrate oxycodone and aspirin tablets to a dose that provides adequate analgesia and minimizes adverse reactions. Continually reevaluate patients receiving oxycodone and aspirin tablets to assess the maintenance of pain control, signs and symptoms of opioid withdrawal, and other adverse reactions, as well to 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 oxycodone and aspirin tablets dosage. If after increasing the dosage, unacceptable opioid-related adverse reactions are observed (including an increase in pain after a 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 Oxycodone and Aspirin Tablets
Do not abruptly discontinue oxycodone and aspirin tablets 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 oxycodone and aspirin tablets, there are a variety of factors that should be considered, including the total daily dose of opioid (including oxycodone and aspirin tablets) 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 comorbid 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 oxycodone and aspirin tablets 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, evaluate 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 an extended period of time 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 ).
CONTRAINDICATIONS
Oxycodone and aspirin tablets are 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 )
- Known or suspected gastrointestinal obstruction, including paralytic ileus (see WARNINGS )
- Hypersensitivity to oxycodone or aspirin, (e.g. angioedema) (see WARNINGS )
- Patients with hemophilia.
- Aspirin should not be used in children or teenagers for viral infections, with or without fever, because of the risk of Reye syndrome (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 )
- Neonatal Opioid Withdrawal Syndrome (see WARNINGS )
- Opioid-Induced Hyperalgesia and Allodynia [see WARNINGS ]
- Interactions with Benzodiazepines and Other CNS Depressants (see WARNINGS )
- Adrenal Insufficiency (see WARNINGS )
- Severe Hypotension (see WARNINGS )
- Gastrointestinal Adverse Reactions (see WARNINGS )
- Seizures (see WARNINGS )
- Withdrawal (see WARNINGS )
Clinical Trials Experience
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
Serious adverse reactions that may be associated with oxycodone and aspirin tablet use include, apnea, circulatory depression, hypotension, respiratory arrest, respiratory depression, and shock (see OVERDOSAGE ).
The most frequently observed non-serious adverse reactions include lightheadedness, dizziness, drowsiness or sedation, nausea, and vomiting. These effects seem to be more prominent in ambulatory than in nonambulatory patients, and some of these adverse reactions may be alleviated if the patient lies down. Other adverse reactions include euphoria, dysphoria, constipation and pruritus.
Aspirin may increase the likelihood of hemorrhage due to its effect on the gastric mucosa and platelet function. Furthermore, aspirin has the potential to cause anaphylaxis in hypersensitive patients as well as angioedema especially in patients with chronic urticaria. Other adverse reactions due to aspirin use include anorexia, reversible hepatotoxicity, leukopenia, thrombocytopenia, purpura, decreased plasma iron concentration, and shortened erythrocyte survival time.
Postmarketing Experience
The following adverse reactions have been identified during post approval use of oxycodone. Because these reactions are 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 adverse reactions obtained from postmarketing experiences with oxycodone and aspirin tablets are listed by organ system and in decreasing order of severity and/or frequency as follows:
Body as a Whole
allergic reaction, malaise, asthenia, headache, anaphylaxis, fever, hypothermia, thirst, increased sweating, accident, accidental overdose, non-accidental overdose.
Cardiovascular
tachycardia, dysrhythmias, hypotension, orthostatic hypotension, bradycardia, palpitations
Central and Peripheral Nervous System
stupor, paresthesia, agitation, cerebral edema, coma, confusion, dizziness, headache, subdural or intracranial hemorrhage, lethargy, seizures, anxiety, mental impairment
Fluid and Electrolyte
dehydration, hyperkalemia, metabolic acidosis, respiratory alkalosis
Gastrointestinal
hemorrhagic gastric/duodenal ulcer, gastric/peptic ulcer, dyspepsia, abdominal pain, diarrhea, eructation, dry mouth, gastrointestinal bleeding, intestinal perforation, nausea, vomiting, transient elevations of hepatic enzymes, hepatitis, Reye syndrome, pancreatitis, intestinal obstruction, ileus
Hearing and Vestibular
hearing loss, tinnitus. Patients with high frequency loss may have difficulty perceiving tinnitus. In these patients, tinnitus cannot be used as a clinical indicator of salicylism.
Hematologic
unspecified hemorrhage, purpura, reticulocytosis, prolongation of prothrombin time, disseminated intravascular coagulation, ecchymosis, thrombocytopenia
Hypersensitivity
acute anaphylaxis, angioedema, asthma, bronchospasm, laryngeal edema, urticaria, anaphylactoid reaction
Metabolic and Nutritional
hypoglycemia, hyperglycemia, acidosis, alkalosis
Musculoskeletal rhabdomyolysis
Ocular
miosis, visual disturbances, red eye
Psychiatric
drug dependence, drug abuse, somnolence, depression, nervousness, hallucination
Reproductive
prolonged pregnancy and labor, stillbirths, lower birth weight infants, antepartum and postpartum bleeding, closure of patent ductus arteriosis
Respiratory System
bronchospasm, dyspnea, hyperpnea, pulmonary edema, tachypnea, aspiration, hypoventilation, laryngeal edema
Skin and Appendages
urticaria, rash, flushing, exfoliative dermatitis, Stevens-Johnson Syndrome (SJS), toxic epidermal necrolysis (TEN), and fixed drug eruption (FDE).
Urogenital
interstitial nephritis, papillary necrosis, proteinuria, renal insufficiency and failure, urinary retention
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 oxycodone and aspirin tablets.
Androgen deficiency
Cases of androgen deficiency have occurred with the use of opioids for an extended period of time (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).
Drug -Drug Interactions (see PRECAUTIONS)
Inhibitors of CYP3A4
Since the CYP3A4 isoenzyme plays a major role in the metabolism of oxycodone and aspirin tablets, drugs that inhibit CYP3A4 activity, such as macrolide antibiotics (e.g., erythromycin), azole-antifungal agents (e.g., ketoconazole), and protease inhibitors (e.g., ritonavir), may cause decreased clearance of oxycodone, which could lead to an increase in oxycodone plasma concentrations. A published study showed that the co-administration of the antifungal drug, voriconazole, increased oxycodone AUC and Cmax by 3.6 and 1.7 fold, respectively. The expected clinical results would be increased or prolonged opioid effects.
Inducers of CYP450
CYP450 inducers, such as rifampin, carbamazepine, and phenytoin, may induce the metabolism of oxycodone, may cause increased clearance of the drug which could lead to a decrease in oxycodone plasma concentrations. A published study showed that the co-administration of rifampin, a drug metabolizing enzyme inducer, decreased oxycodone (oral) AUC and Cmax by 86% and 63% respectively. The expected clinical results would be lack of efficacy or, possibly, development of abstinence syndrome in a patient who had developed physical dependence to oxycodone. Induction of CYP3A4 may be of greatest importance given oxycodone’s metabolic pathways.
DESCRIPTION
Oxycodone and Aspirin Tablets are an immediate-release opioid agonist intended for oral administration only.
Each Oxycodone and Aspirin Tablet contains:
Oxycodone Hydrochloride, USP 4.8355 mg•
Aspirin, USP 325 mg
•4.8355 mg oxycodone HCl is equivalent to 4.3346 mg of oxycodone as the free base.
Oxycodone and Aspirin Tablets USP also contain the following inactive ingredients: microcrystalline cellulose, starch and zinc stearate.

C 18 N 21 NO 4 •HCl MW 351.82
The oxycodone hydrochloride component is Morphinan-6-one, 4,5-epoxy-14-hydroxy-3-methoxy-17-methyl-, hydrochloride, (5α)-, a white to off-white, hygroscopic crystals or powder, odorless, soluble in water; slightly soluble in alcohol and is represented by the following structural formula:

C 9 H 8 O 4 MW 180.16
CLINICAL PHARMACOLOGY
Mechanism of Action
Oxycodone is a full opioid agonist and is relatively selective for the mu-opioid receptor, although it can bind to other opioid receptors at higher doses. The principal therapeutic action of oxycodone is analgesia. Like all full opioid agonists, there is no ceiling effect for analgesia with oxycodone. Clinically, dosage is titrated to provide adequate analgesia and may be limited by adverse reactions, including respiratory and CNS depression.
The precise mechanism of the analgesic action of oxycodone is unknown. However, specific CNS opioid receptors for endogenous compounds with opioid-like activity have been identified throughout the brain and spinal cord and are thought to play a role in the analgesic effects of this drug.
Aspirin (acetylsalicylic acid) works by inhibiting the body’s production of prostaglandins, including prostaglandins involved in inflammation. Prostaglandins cause pain sensations by stimulating muscle contractions and dilating blood vessels throughout the body. In the CNS, aspirin works on the hypothalamus heat-regulating center to reduce fever, however, other mechanisms may be involved.
Pharmacodynamics
Effects on the Central Nervous System
Oxycodone 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 increases in both carbon dioxide tension and electrical stimulation.
Oxycodone 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
Oxycodone 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.
Aspirin can produce gastrointestinal injury (lesions, ulcers) through a mechanism that is not yet completely understood, but may involve a reduction in eicosanoid synthesis by the gastric mucosa. Decreased production of prostaglandins may compromise the defenses of the gastric mucosa and the activity of substances involved in tissue repair and ulcer healing.
Effects on the Cardiovascular System
Oxycodone 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 and sweating and/or orthostatic hypotension.
Use caution in hypovolemic patients, such as those suffering acute myocardial infarction, because oxycodone may cause or further aggravate their hypotension. Caution must also be used in patients with cor pulmonale who have received therapeutic doses of opioids.
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 in in vitro and animal models. 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 opioid agonists. The minimum effective analgesic concentration of oxycodone 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 oxycodone 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 ).
The dose of oxycodone and aspirin tablets must be individualized because the effective analgesic dose for some patients will be too high to be tolerated by other patients (see DOSAGE AND ADMINISTRATION ).
Platelet Aggregation
Aspirin affects platelet aggregation by irreversibly inhibiting prostaglandin cyclo-oxygenase. This effect lasts for the life of the platelet and prevents the formation of the platelet aggregating factor thromboxane A2. Nonacetylated salicylates do not inhibit this enzyme and have no effect on platelet aggregation. At somewhat higher doses, aspirin reversibly inhibits the formation of prostaglandin 12 (prostacyclin), which is an arterial vasodilator and inhibits platelet aggregation.
Pharmacokinetics
Absorption
The mean absolute oral bioavailability of oxycodone in cancer patients was reported to be about 87%. This high oral bioavailability is due to low pre-systemic elimination and/or first-pass metabolism.
Distribution
The volume of distribution after intravenous administration is 211.9 ±186.6 L. Oxycodone has been shown to be 45% bound to human plasma proteins in vitro . Oxycodone has been found in breast milk (see PRECAUTIONS ).
Aspirin is hydrolyzed primarily to salicylic acid in the gut wall and during first-pass metabolism through the liver. Salicylic acid is absorbed rapidly from the stomach, but most of the absorption occurs in the proximal small intestine. Following absorption, salicylate is distributed to most body tissues and fluids, including fetal tissues, breast milk, and the CNS. High concentrations are found in the liver and kidneys. Salicylate is variably bound to serum proteins, particularly albumin.
Elimination
Metabolism
Oxycodone is extensively metabolized by multiple metabolic pathways to produce noroxycodone, oxymorphone and noroxymorphone, which are subsequently glucuronidated. Noroxycodone and noroxymorphone are the major circulating metabolites. CYP3A mediated N-demethylation to noroxycodone is the primary metabolic pathway of oxycodone with a lower contribution from CYP2D6 mediated O-demethylation to oxymorphone. Therefore, the formation of these and related metabolites can, in theory, be affected by other drugs (see Drug-Drug Interactions ).
Noroxycodone exhibits very weak anti-nociceptive potency compared to oxycodone, however, it undergoes further oxidation to produce noroxymorphone, which is active at opioid receptors. Although noroxymorphone is an active metabolite and present at relatively high concentrations in circulation, it does not appear to cross the blood-brain barrier to a significant extent. Oxymorphone, is present in the plasma only at low concentrations and undergoes further metabolism to form its glucuronide and noroxymorphone. Oxymorphone has been shown to be active and possessing analgesic activity but its contribution to analgesia following oxycodone administration is thought to be clinically insignificant, based on the amount formed. Other metabolites (α-and ß-oxycodol, noroxycodol and oxymorphol) may be present at very low concentrations and demonstrate limited penetration into the brain as compared to oxycodone. The enzymes responsible for keto-reduction and glucuronidation pathways in oxycodone metabolism have not been established.
The biotransformation of aspirin occurs primarily in the liver by the microsomal enzyme system. With a plasma half-life of approximately 15 minutes, aspirin is rapidly hydrolyzed to salicylate. At low doses, salicylate elimination follows first-order kinetics. The plasma half-life of salicylate is approximately 2 to 3 hours.
Excretion
Free and conjugated noroxycodone, free and conjugated oxycodone, and oxymorphone are excreted in human urine following a single oral dose of oxycodone. Approximately 8% to 14% of the dose is excreted as free oxycodone over 24 hours after administration.
Approximately 10% of aspirin is excreted as unchanged salicylate in the urine. The major metabolites excreted in the urine are salicyluric acid (75%), salicyl phenolic glucuronide (10%), salicyl acyl glucuronide (5%), and gentisic and gentisuric acid (less than 1%) each. Eighty to 100% of a single dose is excreted in the urine within 24 to 72 hours.
Drug -Drug Interactions (see PRECAUTIONS)
Inhibitors of CYP3A4
Since the CYP3A4 isoenzyme plays a major role in the metabolism of oxycodone and aspirin tablets, drugs that inhibit CYP3A4 activity, such as macrolide antibiotics (e.g., erythromycin), azole-antifungal agents (e.g., ketoconazole), and protease inhibitors (e.g., ritonavir), may cause decreased clearance of oxycodone, which could lead to an increase in oxycodone plasma concentrations. A published study showed that the co-administration of the antifungal drug, voriconazole, increased oxycodone AUC and Cmax by 3.6 and 1.7 fold, respectively. The expected clinical results would be increased or prolonged opioid effects.
Inducers of CYP450
CYP450 inducers, such as rifampin, carbamazepine, and phenytoin, may induce the metabolism of oxycodone, may cause increased clearance of the drug which could lead to a decrease in oxycodone plasma concentrations. A published study showed that the co-administration of rifampin, a drug metabolizing enzyme inducer, decreased oxycodone (oral) AUC and Cmax by 86% and 63% respectively. The expected clinical results would be lack of efficacy or, possibly, development of abstinence syndrome in a patient who had developed physical dependence to oxycodone. Induction of CYP3A4 may be of greatest importance given oxycodone’s metabolic pathways.
HOW SUPPLIED
Oxycodone and Aspirin Tablets, USP are supplied as white to off-white round biconvex tablets debossed “ Є ” above bisect and “61” below bisect on one side, plain on the other side. They are available as follows:
NDC 42806-061-01 Bottles of 100
Store at 20°- 25°C (68° - 77°F); Dispense in a tight, light-resistant container as defined in the USP, with a child-resistant closure (as required).
DEA Order Form Required.
Store Oxycodone and Aspirin Tablets, USP securely and dispose of properly (see PRECAUTIONS; Information for Patients ).
Distributed by:
Epic Pharma, LLC
Laurelton, NY 11413
Rev. 05-2025-00
MF061REV05/25
OE1245
Mechanism of Action
Oxycodone is a full opioid agonist and is relatively selective for the mu-opioid receptor, although it can bind to other opioid receptors at higher doses. The principal therapeutic action of oxycodone is analgesia. Like all full opioid agonists, there is no ceiling effect for analgesia with oxycodone. Clinically, dosage is titrated to provide adequate analgesia and may be limited by adverse reactions, including respiratory and CNS depression.
The precise mechanism of the analgesic action of oxycodone is unknown. However, specific CNS opioid receptors for endogenous compounds with opioid-like activity have been identified throughout the brain and spinal cord and are thought to play a role in the analgesic effects of this drug.
Aspirin (acetylsalicylic acid) works by inhibiting the body’s production of prostaglandins, including prostaglandins involved in inflammation. Prostaglandins cause pain sensations by stimulating muscle contractions and dilating blood vessels throughout the body. In the CNS, aspirin works on the hypothalamus heat-regulating center to reduce fever, however, other mechanisms may be involved.