MORPHINE SULFATE

Morphine sulfate extended-release tablets are for oral use and contain morphine sulfate, an opioid agonist. Each tablet contains the following inactive ingredients common to all strengths: hydroxypropyl methylcellulose, lactose monohydrate, magnesium stearate, silicone dioxide, titanium dioxide, and triacetine. The tablet strengths describe the amount of morphine per tablet as the pentahydrated sulfate salt (morphine sulfate USP). The 15 mg tablets also contain: polyethylene glycol, polydextrose, and FD&C Blue No. 2. The 30 mg tablets also contain: polyethylene glycol, polydextrose, FD&C Blue No. 2, and D&C Red No. 7. The 60 mg tablets also contain: polyethylene glycol, polydextrose, FD&C Yellow No. 6, and iron oxide red. The 100 mg tablets also contain: iron oxide black. The 200 mg tablets also contain: polyethylene glycol, FD&C Blue No. 1, and D&C Yellow No. 10 Lake. Morphine sulfate is an odorless, white, crystalline powder with a bitter taste. It has a solubility of 1 in 21 parts of water and 1 in 1000 parts of alcohol, but is practically insoluble in chloroform or ether. The octanol: water partition coefficient of morphine is 1.42 at physiologic pH and the pK b is 7.9 for the tertiary nitrogen (mostly ionized at pH 7.4). Its molecular weight is 758.83 and its structural formula is: Structural formula

Morphine sulfate extended-release tablets are indicated for the management of severe and persistent pain that requires an extended treatment period with a daily opioid analgesic and for which alternative treatment options are inadequate. Limitations of Use Because of the risks of addiction, abuse, and misuse with opioids, which can occur at any dosage or duration, and because of the greater risks of overdose and death with extended-release/long-acting opioid formulations [see Warnings and Precautions ( 5.1 )], reserve morphine sulfate extended-release tablets for use in patients for whom alternative treatment options (e.g., non-opioid analgesics or immediate-release opioids) are ineffective, not tolerated, or would be otherwise inadequate to provide sufficient management of pain. Morphine sulfate extended-release tablets are not indicated as an as-needed (prn) analgesic. Morphine sulfate extended-release tablets are an opioid agonist indicated for the management of severe and persistent pain that requires an extended treatment period with a daily opioid analgesic and for which alternative treatment options are inadequate. ( 1 ) Limitations of Use ( 1 ) Because of the risks of addiction, abuse, and misuse with opioids, which can occur at any dosage or duration, and because of the greater risks of overdose and death with extended-release/long-acting opioid formulations, reserve morphine sulfate extended-release tablets for use in patients for whom alternative treatment options (e.g., non-opioid analgesics or immediate-release opioids) are ineffective, not tolerated, or would be otherwise inadequate to provide sufficient management of pain. Morphine sulfate extended-release tablets are not indicated as an as-needed (prn) analgesic.

Morphine sulfate extended-release tablets should be prescribed only by healthcare providers who are knowledgeable about the use of extended-release/long-acting opioids and how to mitigate the associated risks. ( 2.1 ) Morphine sulfate extended-release tablets 100 mg and 200 mg tablets, a single dose greater than 60 mg, or a total daily dose greater than 120 mg, are only for use in patients in whom tolerance to an opioid of comparable potency has been established. ( 2.1 ) Patients considered opioid-tolerant are those taking, for one week or longer, at least 60 mg of morphine per day, 25 mcg transdermal fentanyl per hour, 30 mg of oral oxycodone per day, 8 mg of oral hydromorphone per day, 25 mg oral oxymorphone per day, 60 mg oral hydrocodone per day, or an equianalgesic dose of another opioid. ( 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 morphine sulfate extended-release 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. ( 2 , 5 ) 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 morphine sulfate extended-release tablets. Consider this risk when selecting an initial dose and when making dose adjustments. ( 2 , 5 ) Discuss availability of naloxone with the patient and caregiver and assess each patient’s need for access to naloxone, both when initiating and renewing treatment with morphine sulfate extended-release tablets. Consider prescribing naloxone based on the patient’s risk factors for overdose. ( 2.2 , 5.1 , 5.2 , 5.3 ) Instruct patients to swallow morphine sulfate extended-release tablets intact and not to cut, break, chew, crush, or dissolve morphine sulfate extended-release tablets (risk of potentially fatal dose). ( 2.1 , 5.1 ) For opioid-naïve and opioid non-tolerant patients, initiate with 15 mg tablets orally every 8 to 12 hours. ( 2.3 ) Do not abruptly discontinue morphine sulfate extended-release tablets in a physically dependent patient because rapid discontinuation of opioid analgesics has resulted in serious withdrawal symptoms, uncontrolled pain, and suicide. ( 2.5 , 5.14 ) 2.1 Important Dosage and Administration Instructions Morphine sulfate extended-release tablets should be prescribed by healthcare professionals who are knowledgeable about the use of extended-release/long-acting opioids and how to mitigate the associated risks. Morphine sulfate extended-release tablets 100 mg and 200 mg tablets, a single dose greater than 60 mg, or a total daily dose greater than 120 mg, are only for use in patients in whom tolerance to an opioid of comparable potency has been established. Patients considered opioid-tolerant are those taking, for one week or longer, at least 60 mg morphine per day, 25 mcg transdermal fentanyl per hour, 30 mg oral oxycodone per day, 8 mg oral hydromorphone daily, 25 mg oral oxymorphone per day, 60 mg oral hydrocodone per day, or an equianalgesic dose of another opioid. 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 morphine sulfate extended-release 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. 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 morphine sulfate extended-release tablets. Consider this risk when selecting an initial dose and when making dose adjustments [see Warnings and Precautions ( 5.2 )]. Instruct patients to swallow morphine sulfate extended-release tablets whole. Crushing, chewing, or dissolving morphine sulfate extended-release tablets will result in uncontrolled delivery of morphine and can lead to overdose or death [see Warnings and Precautions ( 5.1 )]. Morphine sulfate extended-release tablets are administered orally once every 8 or 12 hours. 2.2 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 morphine sulfate extended-release tablets [see Warnings and Precautions ( 5.2 )] . Inform patients and caregivers about the various ways to obtain naloxone as permitted by individual state naloxone dispensing and prescribing requirements or guidelines (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 and Precautions ( 5.1 , 5.2 , 5.3 )] . Consider prescribing naloxone if the patient has household members (including children) or other close contacts at risk for accidental ingestion or overdose. 2.3 Initial Dosage Use of Morphine Sulfate Extended-Release Tablets as the First Opioid Analgesic (opioid-naïve patients) Initiate treatment with morphine sulfate extended-release tablets at a dose of 15 mg tablets orally every 8 or 12 hours. Use of Morphine Sulfate Extended-Release Tablets in Patients who are not Opioid Tolerant (opioid non-tolerant patients) The starting dose for patients who are not opioid tolerant is morphine sulfate extended-release tablets 15 mg orally every 12 hours. Use of higher starting doses in patients who are not opioid tolerant may cause fatal respiratory depression. Conversion from Other Oral Morphine to Morphine Sulfate Extended-Release Tablets Patients receiving other oral morphine formulations may be converted to morphine sulfate extended-release tablets by administering one-half of the patient’s 24-hour requirement as morphine sulfate extended-release tablets on an every-12-hour schedule or by administering one-third of the patient’s daily requirement as morphine sulfate extended-release tablets on an every-8-hour schedule. Conversion from Other Opioids to Morphine Sulfate Extended-Release Tablets When morphine sulfate extended-release tablets therapy is initiated, discontinue all other opioid analgesics other than those used on an as needed basis for breakthrough pain when appropriate. There are no established conversion ratios for conversion from other opioids to morphine sulfate extended-release tablets defined by clinical trials. Initiate dosing using morphine sulfate extended-release tablets 15 mg orally every 8 to 12 hours. It is safer to underestimate a patient’s 24-hour oral morphine dosage and provide rescue medication (e.g., immediate-release opioid) than to overestimate the 24-hour oral morphine dosage and manage an adverse reaction due to an overdose. While useful tables of opioid equivalents are readily available, there is inter-patient variability in the potency of opioid drugs and opioid formulations. Close observation and frequent titration are warranted until pain management is stable on the new opioid. Monitor patients for signs and symptoms of opioid withdrawal and for signs of oversedation/toxicity after converting patients to morphine sulfate extended-release tablets. Conversion from Parenteral Morphine or Other Opioids (Parenteral or Oral) to Morphine Sulfate Extended-Release Tablets When converting from parenteral morphine or other non-morphine opioids (parenteral or oral) to morphine sulfate extended-release tablets, consider the following general points: Parenteral to oral morphine ratio: Between 2 to 6 mg of oral morphine may be required to provide analgesia equivalent to 1 mg of parenteral morphine. Typically, a dose of morphine that is approximately three times the previous daily parenteral morphine requirement is sufficient. Other parenteral or oral non-morphine opioids to oral morphine ratios: Specific recommendations are not available because of a lack of systematic evidence for these types of analgesic substitutions. Published relative potency data are available, but such ratios are approximations. In general, begin with half of the estimated daily morphine requirement as the initial dose, managing inadequate analgesia by supplementation with immediate-release morphine. Conversion from Methadone to Morphine Sulfate Extended-Release Tablets Regular evaluation is of particular importance when converting methadone to other opioid agonists. The ratio between methadone and other opioid agonists may vary widely as a function of previous dose exposure. Methadone has a long half-life and can accumulate in the plasma. 2.4 Titration and Maintenance of Therapy Individually titrate morphine sulfate extended-release tablets to a dose that provides adequate analgesia and minimizes adverse reactions. Continually reevaluate patients receiving morphine sulfate extended-release tablets to assess the maintenance of pain control, signs and symptoms of opioid withdrawal, and other adverse reactions, as well as to reassess for the development of addiction, abuse, or misuse [see Warnings and Precautions ( 5.1 , 5.14 )] . 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. During use of opioid therapy for an extended period of time, periodically reassess the continued need for the use of opioid analgesics. Patients who experience breakthrough pain may require a dosage adjustment of morphine sulfate extended-release tablets, or may need rescue medication with an appropriate dose of an immediate-release analgesic. If the level of pain increases after dose stabilization, attempt to identify the source of increased pain before increasing the morphine sulfate extended-release 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 and Precautions ( 5 )] . Adjust the dosage to obtain an appropriate balance between management of pain and opioid-related adverse reactions. Because steady-state plasma concentrations are approximated in 1 day, morphine sulfate extended-release tablets dosage adjustments may be done every 1 to 2 days. 2.5 Dosage Modifications with Concomitant Use of Central Nervous System Depressants If the patient is currently taking a central nervous system (CNS) depressant and the decision is made to begin morphine sulfate extended-release tablets, start with the lowest possible dose, 15 mg every 12 hours, monitor patients for signs of respiratory depression, sedation, and hypotension, and consider using a lower dosage of the concomitant CNS depressant [see Warnings and Precautions (5.3) , Drug Interactions (7) ] . 2.6 Safe Reduction or Discontinuation of Morphine Sulfate Extended-Release Tablets Do not abruptly discontinue morphine sulfate extended-release 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 morphine sulfate extended-release tablets, there are a variety of factors that should be considered, including the total daily dose of opioid (including morphine sulfate extended-release 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 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 morphine sulfate extended-release 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 and Precautions ( 5.14 ), Drug Abuse and Dependence ( 9.3 )] .

Morphine sulfate extended-release tablets are contraindicated in patients with: Significant respiratory depression [see Warnings and Precautions ( 5.2 )] Acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment [see Warnings and Precautions ( 5.7 )] Concurrent use of monoamine oxidase inhibitors (MAOIs) or use of MAOIs within the last 14 days [see Warnings and Precautions ( 5.8 ), Drug Interactions ( 7 )] Known or suspected gastrointestinal obstruction, including paralytic ileus [see Warnings and Precautions ( 5.12 )] Hypersensitivity (e.g., anaphylaxis) to morphine [see Adverse Reactions ( 6.2 )] Significant respiratory depression ( 4 ) Acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment ( 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 morphine ( 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 )] Interactions with Benzodiazepine or Other CNS Depressants [see Warnings and Precautions ( 5.3 )] Neonatal Opioid Withdrawal Syndrome [see Warnings and Precautions ( 5.4 )] Opioid-Induced Hyperalgesia and Allodynia [see Warnings and Precautions ( 5.6 )] Adrenal Insufficiency [see Warnings and Precautions ( 5.9 )] Severe Hypotension [see Warnings and Precautions ( 5.10 )] Gastrointestinal Adverse Reactions [see Warnings and Precautions ( 5.12 )] Seizures [see Warnings and Precautions ( 5.13 )] Withdrawal [see Warnings and Precautions ( 5.14 )] Most common adverse reactions (>10%): constipation, nausea, and sedation. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Mallinckrodt at 1-800-778-7898 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch 6.1 Clinical Trial 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. Morphine sulfate extended-release tablets may increase the risk of serious adverse reactions such as those observed with other opioid analgesics, including respiratory depression, apnea, respiratory arrest, circulatory depression, hypotension, or shock [see Overdosage (10) ] . Most Frequently Observed Reactions In clinical trials, the most common adverse reactions with morphine sulfate extended-release tablets were constipation, dizziness, sedation, nausea, vomiting, sweating, dysphoria, and euphoric mood. Some of these effects seem to be more prominent in ambulatory patients and in those not experiencing severe pain. Less Frequently Observed Reactions Cardiovascular disorders: tachycardia, bradycardia, palpitations Eye disorders: visual impairment, vision blurred, diplopia, miosis Gastrointestinal disorders: dry mouth, diarrhea, abdominal pain, constipation, dyspepsia General disorders and administration site conditions: chills, feeling abnormal, edema, edema peripheral, weakness Hepatobiliary disorders: biliary colic Metabolism and nutrition disorders: anorexia Musculoskeletal and connective tissue disorders: muscle rigidity, muscle twitching Nervous system disorders: presyncope, syncope, headache, tremor, uncoordinated muscle movements, convulsion, intracranial pressure increased, taste alteration, paresthesia, nystagmus Psychiatric disorders: agitation, mood altered, anxiety, depression, abnormal dreams, hallucination, disorientation, insomnia Renal and urinary disorders: urinary retention, urinary hesitation, antidiuretic effects Reproductive system and breast disorders: reduced libido and/or potency Respiratory, thoracic and mediastinal disorders: laryngospasm Skin and subcutaneous tissue disorders: pruritus, urticaria, rash Vascular disorders: flushing, hypotension, hypertension 6.2 Postmarketing Experience The following adverse reactions have been identified during post-approval use of morphine sulfate extended-release tablets. 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. Amenorrhea, asthenia, bronchospasm, confusional state, drug hypersensitivity, fatigue, hyperalgesia, hypertonia, ileus, increased hepatic enzymes, intestinal obstruction, lethargy, malaise, pulmonary edema, thinking disturbances, somnolence, and vertigo. 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 morphine sulfate extended-release tablets. Androgen deficiency : Cases of androgen deficiency have occurred with use of opioids for an extended period of time [see Clinical Pharmacology ( 12.2 )] . Hyperalgesia and Allodynia : Cases of hyperalgesia and allodynia have been reported with opioid therapy of any duration [see Warnings and Precautions ( 5.6 )]. 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).

Table 1 includes clinically significant drug interactions with morphine sulfate extended-release tablets. Table 1: Clinically Significant Drug Interactions with Morphine Sulfate Extended-Release Tablets 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, can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death [see Warnings and Precautions ( 5.3 )] . 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 [see Dosage and Administration ( 2.2 , 2.5 ), Warnings and Precautions ( 5.1 , 5.2 , 5.3 )] . Examples: Benzodiazepines and other sedative 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 morphine sulfate extended-release tablets if serotonin syndrome is suspected. Examples: Selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), triptans, 5-HT3 receptor antagonists, drugs that affect 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 (5.8) ] . Intervention: Do not use morphine sulfate extended-release tablets in patients taking MAOIs or within 14 days of stopping such treatment. Examples: phenelzine, tranylcypromine, linezolid Mixed Agonist/Antagonist and Partial Agonist Opioid Analgesics Clinical Impact: May reduce the analgesic effect of morphine sulfate extended-release tablets and/or precipitate withdrawal symptoms. Intervention: Avoid concomitant use. Examples: butorphanol, nalbuphine, pentazocine, buprenorphine Muscle Relaxants Clinical Impact: Morphine may enhance the neuromuscular blocking action of skeletal muscle relaxants and produce an increased degree of respiratory depression. Intervention: Because of respiratory depression may be greater than otherwise expected, decrease the dosage of morphine sulfate extended-release tablets 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 naloxone for the emergency treatment of opioid overdose [see Dosage and Administration ( 2.2 ), Warnings and Precautions ( 5.2 , 5.3 )] . Examples: Cyclobenzaprine, metaxalone Cimetidine Clinical Impact: The concomitant use of cimetidine can potentiate morphine effects and increase risk of hypotension, respiratory depression, profound sedation, coma, and death. Intervention: Evaluate patients for signs of respiratory depression that may be greater than otherwise expected and decrease the dosage of morphine sulfate extended-release tablets and/or cimetidine as necessary. 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. 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 morphine sulfate extended-release tablets are used concomitantly with anticholinergic drugs. P-Glycoprotein (P-gp) Inhibitors Clinical Impact: The concomitant use of PGP-inhibitors can increase the exposure to morphine by about two-fold and can increase risk of hypotension, respiratory depression, profound sedation, coma, and death. Intervention: Evaluate patients for signs of respiratory depression that may be greater than otherwise expected and decrease the dosage of morphine sulfate extended-release tablets and/or the PGP-inhibitor as necessary. Example: Quinidine Serotonergic Drugs : Concomitant use may result in serotonin syndrome. Discontinue morphine sulfate extended-release tablets if serotonin syndrome is suspected. ( 7 ) Mixed Agonist/Antagonist and Partial Agonist Opioid Analgesics : Avoid use with morphine sulfate extended-release tablets because they may reduce analgesic effect of morphine sulfate extended-release tablets or precipitate withdrawal symptoms. ( 5.14 , 7 )