ASCOMP WITH CODEINE

Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP is supplied in capsule form for oral administration. Each capsule contains the following active ingredients: Butalbital, USP…………………50mg Aspirin, USP……………………325mg Caffeine, USP…………………..40mg Codeine phosphate, USP………30mg Butalbital (5-allyl-5-isobutylbarbituric acid) is a short-to intermediate-acting barbiturate. It has the following structural formula: Aspirin (benzoic acid, 2-(acetyloxy)-) is a nonsteroidal anti-inflammatory drug. It has the following structural formula : Caffeine (1,3,7-trimethylxanthine), a methylxanthine, is a central nervous system stimulant. It has the following structural formula: Codeine phosphate (7,8-Didehydro-4,5α-epoxy-3-methoxy-17-methylmorphinan-6α-ol phosphate (1:1) (salt) hemihydrate) is an opioid agonist. It has the following structural formula : Inactive Ingredients : Corn Starch, D&C Red No. 28, D&C Yellow No. 10, FD&C Blue No. 1, FD&C Red No. 40, Gelatin, Microcrystalline Cellulose, Sodium Lauryl Sulfate, Stearic Acid, Talc, and Titanium Dioxide. The capsules are printed with edible black ink. The following structural formula Butalbital (5-allyl-5-isobutylbarbituric acid) is a short-to intermediate-acting barbiturate. The following structural formula Aspirin (benzoic acid, 2-(acetyloxy)-) is a nonsteroidal anti-inflammatory drug. The following structural formula Caffeine (1,3,7-trimethylxanthine), a methylxanthine, is a central nervous system stimulant. The following structural formula Codeine phosphate (7,8-Didehydro-4,5α-epoxy-3-methoxy-17-methylmorphinan-6α-ol phosphate (1:1) (salt) hemihydrate) is an opioid agonist.

Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP is indicated for the management of the symptom complex of tension (or muscle contraction) headache, when non-opioid analgesic and alternative treatments are inadequate. Limitations of Use Because of the risks of addiction, abuse, misuse, overdose, and death, which can occur at any dosage or duration and persist over the course of therapy [ see Warnings and Precautions (5.1) ], reserve opioid analgesics, including Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP, for use in patients for whom alternative treatment options are ineffective, not tolerated, or would be otherwise inadequate to provide sufficient management of pain. Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP 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. Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP is a combination of butalbital, a barbiturate, aspirin, a nonsteroidal anti-inflammatory drug, caffeine, a methylxanthine, and codeine phosphate, an opioid agonist, and is indicated for the management of the symptom complex of tension (or muscle contraction) headache, when other non-opioid analgesics and alternative treatments are inadequate. Limitations of Use : Because of the risks of addiction, abuse, misuse, overdose, and death, which can occur at any dosage or duration and persist over the course of therapy, reserve opioid analgesics, including Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP, for use in patients for whom alternative treatment options are ineffective, not tolerated, or would be otherwise inadequate to provide sufficient management of pain. ( 1 , 5.1 )

Periodically reassess patients receiving Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP to evaluate the continued need for opioid analgesics to maintain pain control, for the signs or symptoms of adverse reactions, and for the development of addiction, abuse, or misuse. ( 2.1 ) Discuss opioid overdose reversal agents and options for acquiring them with the patient and/or caregiver, both when initiating and renewing treatment with Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP, especially if the patient has additional risk factors for overdose, or close contacts at risk for exposure and overdose. ( 2.2 , 5.1 , 5.2 , 5.3 ) Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP should be prescribed only by healthcare professionals who are knowledgeable about the use of opioids and how to mitigate the associated risks. ( 2.1 ) Use the lowest effective dosage for the shortest duration of time consistent with individual patient treatment goals. Reserve titration to higher doses of Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP 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. ( 2.1 , 5 ) 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, ( 2.1 ) 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. ( 2.1 , 5.1 ) Respiratory depression can occur at any time during opioid therapy, especially when initiating and following dosage increases with Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP. Consider this risk when selecting an initial dose and when making dose adjustments. ( 2.1 , 5.2 ) Initiate treatment with one or two capsules every 4 hours as needed for pain, and at the lowest dose necessary to achieve adequate analgesia. Titrate the dose based upon the individual patient’s response to their initial dose of Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP. Total daily dose should not exceed 6 capsules. ( 2 , 5 ) Do not rapidly reduce or abruptly discontinue Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP in a physically dependent patient because rapid reduction or abrupt discontinuation of opioid analgesics has resulted in serious withdrawal symptoms, uncontrolled pain, and suicide. ( 2.4 , 5.16 ) 2.1 Important Dosage and Administration Instructions Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP 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 and Precautions ( 5 )] . Because the risk of overdose increases as opioid doses increase, reserve titration to higher doses of Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP 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 a 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 and Precautions ( 5.1 )] . Respiratory depression can occur at any time during opioid therapy, especially when initiating and following dosage increases with Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP. Consider this risk when selecting an initial dose and when making dose adjustments [see Warnings and Precautions ( 5 )] . 2.2 Patient Access to Naloxone for the Emergency Treatment of Opioid Overdose Inform patients and caregivers about opioid reversal agents (e.g., naloxone, nalmefene). Discuss the importance of having access to an opioid overdose reversal agent, especially if the patient has risk factors for overdose (e.g., concomitant use of CNS depressants, a history of opioid use disorder, or prior opioid overdose) or if there are household members (including children) or other close contacts at risk for accidental ingestion or opioid overdose. The presence of risk factors for overdose should not prevent the management of pain in any patient [see Warnings and Precautions ( 5.1 , 5.2 , 5.3 )] . Discuss the options for obtaining an opioid overdose reversal agent (e.g., prescription, over-the-counter, or as part of a community-based program) [see Warnings and Precautions ( 5.2 )] . There are important differences among the opioid overdose reversal agents, such as route of administration, product strength, approved patient age range, and pharmacokinetics. Be familiar with these differences, as outlined in the approved labeling for those products, prior to recommending or prescribing such an agent. 2.3 Dosing Information One or two capsules every 4 hours as needed for pain. Total daily dosage should not exceed 6 capsules. Use the lowest dose necessary to achieve adequate analgesia. Titrate the dose based upon the individual patient’s response to their initial dose of Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP. 2.4 Safe Reduction or Discontinuation of Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP Do not rapidly reduce or abruptly discontinue Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP in patients who may be physically dependent on opioids. Rapid reduction or abrupt discontinuation of opioid analgesics in patients who are physically dependent on opioids has resulted in serious withdrawal symptoms, uncontrolled pain, and suicide. Rapid reduction or abrupt 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 Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP, there are a variety of factors that should be considered, including the total daily dose of opioid (including Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP) 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 used 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 Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP 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 internal 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 analgesics [see Warnings and Precautions ( 5.16 ), Drug Abuse and Dependence ( 9.3 )] .

Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP is contraindicated for: All children younger than 12 years of age [see Warnings and Precautions ( 5.6 ) ] Postoperative management in children younger than 18 years of age following tonsillectomy and/or adenoidectomy [see Warnings and Precautions ( 5.6 ) ]. Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP is also contraindicated in patients with: Significant respiratory depression [see Warnings and Precautions ( 5.9 ) ] Acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment [see Warnings and Precautions ( 5.9 ) ] Concurrent use of monoamine oxidase inhibitors (MAOIs) or use of MAOIs within the last 14 days [see Warnings and Precautions ( 5.10 ),Drug Interactions ( 7 ) ]. Known or suspected gastrointestinal obstruction, including paralytic ileus [see Warnings and Precautions ( 5.14 )] Hypersensitivity or intolerance to aspirin, caffeine, butalbital, or codeine. Hemophilia [see Warnings and Precautions ( 5.19 ) ] Reye’s Syndrome [see Warnings and Precautions ( 5.20 ) ] Known allergy to nonsteroidal anti-inflammatory drugs (NSAIDs) [see Warnings and Precautions ( 5.23 ) ] Syndrome of asthma, rhinitis, and nasal polyps [see Warnings and Precautions ( 5.23 ) ] Children younger than 12 years of age ( 4 ) Post-operative management in children younger than 18 years of age following tonsillectomy and/or adenoidectomy ( 4 ) Significant respiratory depression ( 4 ) Acute or severe bronchial asthma ( 4 ) Concurrent use of monoamine oxidase inhibitors (MAOIs) or use of MAOIs within the last 14 days ( 4 ) Known or suspected gastrointestinal obstruction, including paralytic ileus ( 4 ) Hypersensitivity to aspirin, caffeine, butalbital, or codeine ( 4 ) Hemophilia ( 4 ) Reye’s Syndrome ( 4 ) Known allergy to NSAIDs ( 4 ) Syndrome of asthma, rhinitis, and nasal polyps ( 4 )

The following serious adverse reactions are described, or described in greater detail, in other sections: Addiction, Abuse, and Misuse [see Warnings and Precautions ( 5.1 )] Life-Threatening Respiratory Depression [see Warnings and Precautions ( 5.2 ) Risks from Concomitant Use with Benzodiazepines or Other CNS Depressants [see Warnings and Precautions ( 5.3 )] Neonatal Opioid Withdrawal Syndrome [see Warnings and Precautions ( 5.4 )] Ultra-Rapid Metabolism of Codeine and Other Risk Factors for Life-Threatening Respiratory Depression in Children [ see Warnings and Precautions ( 5.6 ) ] Opioid-Induced Hyperalgesia and Allodynia [see Warnings and Precautions ( 5.8 )] Adrenal Insufficiency [see Warnings and Precautions ( 5.11 ) ] Severe Hypotension [see Warnings and Precautions ( 5.12 ) ] Risk of Use in Patients with Gastrointestinal Conditions Including Peptic Ulcer Disease [see Warnings and Precautions ( 5.14 )] Increase Risk of Seizures in Patients with Seizure Disorders [see Warnings and Precautions ( 5.15 )] Withdrawal [see Warnings and Precautions ( 5.16 ) ] Coagulation Abnormalities and Bleeding Risks [see Warnings and Precautions ( 5.19 ) ] Reye’s Syndrome [see Warnings and Precautions ( 5.20 ) ] Serious Skin Reactions [see Warnings and Precautions ( 5.21 )] Allergy [see Warnings and Precautions ( 5.23 ) ] Most common adverse reactions (incidence > 1%) are nausea and/or abdominal pain, drowsiness, and dizziness. ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact LGM Pharma Solutions, LLC at 1-877-288-1495 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 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. Incidence in Controlled Clinical Trials : The following table summarizes the incidence rates of the adverse events reported by at least 1% of the Butalbital, Aspirin, Caffeine, and Codeine Phosphate, USP Capsules treated patients in controlled clinical trials comparing Butalbital, Aspirin, Caffeine, and Codeine Phosphate, USP Capsules to placebo, and provides a comparison to the incidence rates reported by the placebo-treated patients. The prescriber should be aware that these figures cannot be used to predict the incidence of side effects in the course of usual medical practice where patient characteristics and other factors differ from those that prevailed in the clinical trials. Similarly, the cited frequencies cannot be compared with figures obtained from other clinical investigations involving different treatments, uses, and investigators. Adverse Events Reported by at Least 1% of Butalbital, Aspirin, Caffeine, and Codeine Phosphate, USP Capsules Treated Patients During Placebo Controlled Clinical Trials Incidence Rate of Adverse Events Body System/Adverse Event Butalbital, Aspirin, Caffeine, and Placebo Codeine Phosphate, USP (N =377) Capsules (N=382) Central Nervous Drowsiness 2.4% 0.5% Dizziness/Lightheadedness 2.6% 0.5% Intoxicated Feeling 1.0% 0% Gastrointestinal Nausea/Abdominal Pain 3.7% 0.8% Other Adverse Events Reported During Controlled Clinical Trials The listing that follows represents the proportion of the 382 patients exposed to Butalbital, Aspirin, Caffeine, and Codeine Phosphate, USP Capsules while participating in the controlled clinical trials who reported, on at least one occasion, an adverse event of the type cited. All reported adverse events, except those already presented in the previous table, are included. It is important to emphasize that, although the adverse events reported did occur while the patient was receiving Butalbital, Aspirin, Caffeine, and Codeine Phosphate, USP Capsules, the adverse events were not necessarily caused by Butalbital, Aspirin, Caffeine, and Codeine Phosphate, USP Capsules. Adverse events are classified by body system and frequency. “Frequent” is defined as an adverse event which occurred in at least 1/100 (1%) of the patients; all adverse events listed in the previous table are frequent. “Infrequent” is defined as an adverse event that occurred in less than 1/100 patients but at least 1/1000 patients. All adverse events tabulated below are classified as infrequent. Central Nervous : headache, shaky feeling, tingling, agitation, fainting, fatigue, heavy eyelids, high energy, hot spells, numbness, and sluggishness. Autonomic Nervous : dry mouth and hyperhidrosis. Gastrointestinal : vomiting, difficulty swallowing, and heartburn. Cardiovascular : tachycardia. Musculoskeletal : leg pain and muscle fatigue. Genitourinary : diuresis. Miscellaneous : pruritus, fever, earache, nasal congestion, and tinnitus. The following adverse drug reactions have been reported with the components of Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP. Potential effects of high dosage are listed in the [see Overdosage ( 10 ) ] section of this insert. Aspirin : occult blood loss, hemolytic anemia, iron deficiency anemia, gastric distress, heartburn, nausea, peptic ulcer, prolonged bleeding time, acute airway obstruction, renal toxicity when taken in high doses for prolonged periods, impaired urate excretion, hepatitis. Caffeine : cardiac stimulation, irritability, tremor, dependence, nephrotoxicity, hyperglycemia. Codeine : nausea, vomiting, drowsiness, lightheadedness, constipation, pruritus. 6.2 Postmarketing Experience The following adverse reactions have been identified during post approval use of Butalbital, Aspirin, Caffeine, and Codeine Phosphate, USP Capsules. 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. Central Nervous : abuse, addiction, anxiety, depression, disorientation, hallucination, hyperactivity, insomnia, libido decrease, nervousness, neuropathy, psychosis, sedation, sexual activity increase, slurred speech, twitching, unconsciousness, vertigo. Autonomic Nervous : epistaxis, flushing, miosis, salivation. Gastrointestinal : anorexia, appetite increased, constipation, diarrhea, esophagitis, gastroenteritis, gastrointestinal spasm, hiccup, mouth burning, pyloric ulcer. Cardiovascular : chest pain, hypotensive reaction, palpitations, syncope. Skin : erythema, erythema multiforme, exfoliative dermatitis, Stevens-Johnson Syndrome (SJS), hives, rash, toxic epidermal necrolysis, and fixed drug eruption (FDE). Urinary : kidney impairment, urinary difficulty. Miscellaneous : allergic reaction, anaphylactic shock, cholangiocarcinoma, drug interaction with erythromycin (stomach upset), edema. 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 Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP. Androgen deficiency : Cases of androgen deficiency have occurred with use of opioids for an extended period of time. Hyperalgesia and Allodynia : Cases of hyperalgesia and allodynia have been reported with opioid therapy of any duration [see Warnings and Precautions ( 5.8 )] . Hyp o glycemia : 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). Opioid-induced esophageal dysfunction (OIED): Cases of OIED have been reported in patients taking opioids and may occur more frequently in patients taking higher doses of opioids, and/or in patients taking opioids longer term [see Warnings and Precautions ( 5.14 )] . Adverse Reactions from Observational Studies A prospective, observational cohort study estimated the risks of addiction, abuse, and misuse in patients initiating long-term use of Schedule II opioid analgesics between 2017 and 2021. Study participants included in one or more analyses had been enrolled in selected insurance plans or health systems for at least one year, were free of at least one outcome at baseline, completed a minimum number of follow-up assessments, and either: 1) filled multiple extended-release/long-acting opioid analgesic prescriptions during a 90 day period (n=978); or 2) filled any Schedule II opioid analgesic prescriptions covering at least 70 of 90 days (n=1,244). Those included also had no dispensing of the qualifying opioids in the previous 6 months. Over 12 months: • approximately 1% to 6% of participants across the two cohorts newly met criteria for addiction, as assessed with two validated interview-based measures of moderate-to-severe opioid use disorder based on Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria and • approximately 9% and 22% of participants across the two cohorts newly met criteria for prescription opioid abuse and misuse [defined in Drug Abuse and Dependence ( 9.2 )] , respectively, as measured with a validated self-reported instrument. A retrospective, observational cohort study estimated the risk of opioid-involved overdose or opioid overdose-related death in patients with new long-term use of Schedule II opioid analgesics from 2006 through 2016 (n=220, 249). Included patients had been enrolled in either one of two commercial insurance programs, one managed care program, or one Medicaid program for at least 9 months. New long-term use was defined as having Schedule II opioid analgesic prescriptions covering at least 70 days' supply over the 3 months prior to study entry and none during the preceding 6 months. Patients were excluded if they had an opioid-involved overdose in the 9 months prior to study entry. Overdose was measured using a validated medical code-based algorithm with linkage to the National Death Index database. The 5-year cumulative incidence estimates for opioid-involved overdose or opioid overdose-related death ranged from approximately 1.5% to 4% across study sites, counting only the first event during follow-up. Approximately 17% of first opioid overdoses observed over the entire study period (5-11 years, depending on the study site) were fatal. Higher baseline opioid dose was the strongest and most consistent predictor of opioid-involved overdose or opioid overdose-related death. Study exclusion criteria may have selected patients at lower risk of overdose, and substantial loss to follow-up (approximately 80%) also may have biased estimates. The risk estimates from the studies described above may not be generalizable to all patients receiving opioid analgesics, such as those with exposures shorter or longer than the duration evaluated in the studies.

Table 1 includes clinically significant drug interactions with Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP. Table 1: Clinically Significant Drug Interactions with Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP Inhibitors of CYP3A4 Clinical Impact: The concomitant use of Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP with CYP3A4 inhibitors may result in an increase in codeine plasma concentrations with subsequently greater metabolism by cytochrome CYP2D6, resulting in greater morphine levels, which could increase or prolong adverse reactions and may cause potentially fatal respiratory depression, particularly when an inhibitor is added after a stable dose of Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP is achieved. After stopping a CYP3A4 inhibitor, as the effects of the inhibitor decline, it may result in lower codeine levels, greater norcodeine levels, and less metabolism via 2D6 with resultant lower morphine levels [see Clinical Pharmacology ( 12.3 )] , resulting in decreased opioid efficacy or a withdrawal syndrome in patients who had developed physical dependence to codeine. Intervention: If concomitant use with CYP3A4 inhibitor is necessary, consider dosage reduction of Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP until stable drug effects are achieved. Evaluate patients at frequent intervals for respiratory depression and sedation. If a CYP3A4 inhibitor is discontinued, consider increasing the Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP dosage until stable drug effects are achieved. Evaluate for signs of opioid withdrawal. Examples: Macrolide antibiotics (e.g., erythromycin), azole-antifungal agents (e.g. ketoconazole), protease inhibitors (e.g., ritonavir) CYP3A4 Inducers Clinical Impact: The concomitant use of Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP and CYP3A4 inducers can result in lower codeine levels, greater norcodeine levels, and less metabolism via 2D6 with resultant lower morphine levels [see Clinical Pharmacology ( 12.3 ) ] , resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence [see Warnings and Precautions ( 5.16 ) ]. After stopping a CYP3A4 inducer, as the effects of the inducer decline, the codeine plasma concentration may increase with subsequently greater metabolism by cytochrome CYP2D6, resulting in greater morphine levels [see Clinical Pharmacology ( 12.3 ) ] , which could increase or prolong both the therapeutic effects and adverse reactions, and may cause serious respiratory depression. Intervention: If concomitant use of a CYP3A4 inducer is necessary, evaluate patients at frequent intervals for reduced efficacy and signs of opioid withdrawal and consider increasing the Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP dosage as needed. If a CYP3A4 inducer is discontinued, consider Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP dosage reduction, and evaluate patients at frequent intervals for signs of respiratory depression and sedation. Examples: Rifampin, carbamazepine, phenytoin Inhibitors of CYP2D6 Clinical Impact: Codeine in Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP is metabolized by CYP2D6 to form morphine. The concomitant use of Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP and CYP2D6 inhibitors can increase the plasma concentration of codeine, but can decrease the plasma concentrations of active metabolite morphine which could result in reduced analgesic efficacy or symptoms of opioid withdrawal, particularly when an inhibitor is added after a stable dose of Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP is achieved [see Clinical Pharmacology ( 12.3 ) ]. After stopping a CYP2D6 inhibitor, as the effects of the inhibitor decline, the codeine plasma concentration will decrease but the active metabolite morphine plasma concentration will increase, which could increase or prolong adverse reactions and may cause potentially fatal respiratory depression [see Clinical Pharmacology ( 12.3 ) ]. Intervention: If concomitant use with a CYP2D6 inhibitor is necessary, or if a CYP2D6 inhibitor is discontinued after concomitant use, consider dosage adjustment of Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP and evaluate patients at frequent intervals. If concomitant use with CYP2D6 inhibitors is necessary, evaluate patients for reduced efficacy or signs and symptoms of opioid withdrawal and consider increasing the Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP as needed. After stopping use of a CYP2D6 inhibitor, consider reducing the Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP and evaluate patients at frequent intervals for signs and symptoms of respiratory depression or sedation. Examples: paroxetine, fluoxetine, bupropion, quinidine Benzodiazepines and other Central Nervous System (CNS) Depressants Clinical Impact: Due to additive pharmacologic effect, the concomitant use of benzodiazepines or other CNS depressants including alcohol, increases the risk of respiratory depression, profound sedation, coma, and death. Intervention: Reserve concomitant prescribing of these drugs for use in patients for whom alternative treatment options are inadequate. Limit dosages and durations to the minimum required. Inform patients and caregivers of this potential interaction and educate them on the signs and symptoms of respiratory depression (including sedation). If concomitant use is warranted, consider prescribing naloxone for the emergency treatment of opioid overdose. Examples: Benzodiazepines and other sedatives/hypnotics, anxiolytics, tranquilizers, muscle relaxants, general anesthetics, antipsychotics, other opioids, alcohol. Serotonergic Drugs Clinical Impact: The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. Intervention: If concomitant use is warranted, frequently evaluate the patient, particularly during treatment initiation and dose adjustment. Discontinue Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP immediately if serotonin syndrome is suspected. Examples: Selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), triptans, 5-HT 3 receptor antagonists, drugs that effect the serotonin neurotransmitter system (e.g., mirtazapine, trazodone, tramadol), certain muscle relaxants (i.e., cyclobenzaprine, metaxalone), monoamine oxidase (MAO) inhibitors (those intended to treat psychiatric disorders and also others, such as linezolid and intravenous methylene blue). Monoamine Oxidase Inhibitors (MAOIs) Clinical Impact: MAOI interactions with opioids may manifest as serotonin syndrome or opioid toxicity (e.g., respiratory depression, coma) [ see Warnings and Precautions ( 5.10 ) ]. Intervention: Do not use Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP in patients taking MAOIs or within 14 days of stopping such treatment. If urgent use of an opioid is necessary, use test doses and frequent titration of small doses of other opioids (such as oxycodone, hydrocodone, oxymorphone, or buprenorphine) to treat pain while closely monitoring blood pressure and signs and symptoms of CNS and respiratory depression. Examples: phenelzine, tranylcypromine, linezolid Mixed Agonist/Antagonist and Partial Agonist Opioid Analgesics Clinical Impact: May reduce the analgesic effect of Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP and/or precipitate withdrawal symptoms. Intervention: Avoid concomitant use. Examples: butorphanol, nalbuphine, pentazocine, buprenorphine, Muscle Relaxants Clinical Impact: Codeine may enhance the neuromuscular blocking action of skeletal muscle relaxants and produce an increased degree of respiratory depression. Intervention: Evaluate patients for signs of respiratory depression that may be greater than otherwise expected, decrease the dosage of Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP and/or the muscle relaxant as necessary. Due to the risk of respiratory depression with concomitant use of skeletal muscle relaxants and opioids, consider prescribing an opioid overdose reversal agent [see Dosage and Administration ( 2.3 ), Warnings and Precautions ( 5.3 , 5.4 )] . Examples: Cyclobenzaprine, metaxalone. Diuretics Clinical Impact: Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone. Intervention: Evaluate patients for signs of diminished diuresis and/or effects on blood pressure and increase the dosage of the diuretic as needed. The effectiveness of diuretics in patients with underlying renal or cardiovascular disease may be diminished by the concomitant administration of aspirin due to inhibition of renal prostaglandins, leading to decreased renal blood flow and salt and fluid retention. Anticholinergic Drugs Clinical Impact: The concomitant use of anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Intervention: Evaluate patients for signs of urinary retention or reduced gastric motility when Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP is used concomitantly with anticholinergic drugs. Anticoagulants Clinical Impact: Aspirin may enhance the effects of anticoagulants. Concurrent use may increase the risk of bleeding. Aspirin can also displace warfarin from protein binding sites, leading to prolongation of both the prothrombin time and the bleeding time. Intervention: Evaluate patients for signs of bleeding. Examples: Warfarin, heparin, enoxaparin, clopidogrel, prasugrel, rivaroxaban, apixaban Uricosuric Agents Clinical Impact: Aspirin inhibits the uricosuric effects of uricosuric agents. Intervention: Avoid concomitant use. Examples: Probenecid Carbonic Anhydrase Inhibitors Clinical Impact: Concurrent use with aspirin can lead to high serum concentrations of the carbonic anhydrase inhibitor and cause toxicity due to competition at the renal tubule for secretion. Intervention: Consider reducing the dose of the carbonic anhydrase inhibitor. Evaluate the patients for any adverse effects from the carbonic anhydrase inhibitor. Examples: Acetazolamide, methazolamide Methotrexate Clinical Impact: Aspirin may enhance the toxicity of methotrexate by displacing it from its plasma protein binding sites and/or reducing its renal clearance. Intervention: Use caution if using concomitantly, especially in elderly patients or patients with renal impairment. Evaluate patients for methotrexate toxicity. Nephrotoxic Agents Clinical Impact: Concomitant use with aspirin may lead to additive nephrotoxicity due to the inhibition of renal prostaglandins by aspirin. Also, the plasma concentration of aspirin is increased by conditions that reduce the glomerular filtration rate or tubular secretion. Intervention: Use Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP with caution if used concomitantly with nephrotoxic agents. Evaluate the renal function of patients. Examples: Aminoglycosides, amphotericin B, systemic bacitracin, cisplatin, cyclosporine, foscarnet, or parenteral vancomycin Angiotensin Converting Enzyme (ACE) Inhibitors Clinical Impact: The hyponatremic and hypotensive effects of ACE inhibitors may be diminished by the concomitant administration of aspirin due to its indirect effect on the renin- angiotensin conversion pathway. Intervention: Use caution if using concomitantly. Evaluate the blood pressure and renal function of patients. Examples: Ramipril, captopril Beta Blockers Clinical Impact: The hypotensive effects of beta blockers may be diminished by the concomitant administration of aspirin due to inhibition of renal prostaglandins, leading to decreased renal blood flow, and salt and fluid retention. Intervention: Use caution if using concomitantly. Evaluate the blood pressure and renal function of patients. Examples: Metoprolol, propranolol Hypoglycemic Agents Clinical Impact: Aspirin may increase the serum glucose-lowering action of insulin and sulfonylureas leading to hypoglycemia. Intervention: Patients should be advised to consult a physician if any signs or symptoms of hypoglycemia occur. Examples: Insulin, glimepiride, glipizide Anticonvulsants Clinical Impact: Aspirin can displace protein-bound phenytoin and valproic acid, leading to a decrease in the total concentration of phenytoin and an increase in serum valproic acid levels. Intervention: Use caution if using concomitantly. Examples: Phenytoin, valproic acid Nonsteroidal Anti-inflammatory Drugs (NSAIDs) Clinical Impact: Concurrent use with aspirin may increase the risk of bleeding or lead to decreased renal function. Aspirin may enhance serious side effects and toxicity of ketorolac by displacing it from its plasma protein binding sites and/or reducing its renal clearance. Intervention: Avoid concomitant use. Examples: Ketorolac, ibuprofen, naproxen, diclofenac Corticosteroids Clinical Impact: In patients receiving concomitant corticosteroids and chronic use of aspirin, withdrawal of corticosteroids may result in salicylism because corticosteroids enhance renal clearance of salicylates and their withdrawal is followed by return to normal rates of renal clearance. Intervention: Avoid concomitant use. Serotonergic Drugs: Concomitant use may result in serotonin syndrome. Discontinue Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP if serotonin syndrome is suspected. ( 7 ) Mixed Agonist/Antagonist and Partial Agonist Opioid Analgesics : Avoid use with Butalbital, Aspirin, Caffeine, and Codeine Phosphate Capsules, USP because they may reduce analgesic effect of Butalbital, Aspirin, Caffeine, and Codeine Phosphate, USP or precipitate withdrawal symptoms. ( 7 )