WARNINGS AND PRECAUTIONS
Addiction, Abuse, and Misuse
Morphine sulfate extended-release tablets contain morphine, a Schedule II controlled substance. As an opioid, morphine sulfate extended-release tablets expose its users to the risks of addiction, abuse, and misuse. As modified-release products such as morphine sulfate extended-release tablets deliver the opioid over an extended period of time, there is a greater risk for overdose and death due to the larger amount of morphine present [see Drug Abuse and Dependence].
Although the risk of addiction in any individual is unknown, it can occur in patients appropriately prescribed morphine sulfate extended-release tablets and in those who obtain the drug illicitly. Addiction can occur at recommended doses and if the drug is misused or abused.
Assess each patient’s risk for opioid addiction, abuse, or misuse prior to prescribing morphine sulfate extended-release tablets, and monitor all patients receiving opioids for development of these behaviors or conditions. Risks are increased in patients with a personal or family history of substance abuse (including drug or alcohol abuse or addiction) or mental illness (e.g., major depression). The potential for these risks should not, however, prevent the proper management of pain in any given patient. Patients at increased risk may be prescribed modified-release opioid formulations such as morphine sulfate extended-release tablets, but use in such patients necessitates intensive counseling about the risks of proper use of morphine sulfate extended-release tablets along with intensive monitoring for signs of addiction, abuse, and misuse.
Abuse or misuse of morphine sulfate extended-release tablets by crushing, chewing, snorting, or injecting the dissolved product will result in the uncontrolled delivery of morphine and can result in overdose and death [see
Opioid agonists such as morphine sulfate extended-release tablets are sought by drug abusers and people with addiction disorders and are subject to criminal diversion. Consider these risks when prescribing or dispensing morphine sulfate extended-release tablets. Strategies to reduce these risks include prescribing the drug in the smallest appropriate quantity and advising the patient on the proper disposal of unused drug [see Patient Counseling Information]. Contact local state professional licensing board or state controlled substances authority for information on how to prevent and detect abuse or diversion of this product.
Life-Threatening Respiratory Depression
Serious, life-threatening, or fatal respiratory depression has been reported with the use of modified-release opioids, even when used as recommended. Respiratory depression from opioid use, if not immediately recognized and treated, may lead to respiratory arrest and death. Management of respiratory depression may include close observation, supportive measures, and use of opioid antagonists, depending on the patient’s clinical status [see
]. Carbon dioxide (CO2) retention from opioid-induced respiratory depression can exacerbate the sedating effects of opioids.
While serious, life-threatening, or fatal respiratory depression can occur at any time during the use of morphine sulfate extended-release tablets, the risk is greatest during the initiation of therapy or following a dose increase. Closely monitor patients for respiratory depression when initiating therapy with morphine sulfate extended-release tablets and following dose increases.
To reduce the risk of respiratory depression, proper dosing and titration of morphine sulfate extended-release tablets are essential [see
Dosage and Administration (2)
]. Overestimating the morphine sulfate extended-release tablets dose when converting patients from another opioid product can result in a fatal overdose with the first dose.
Accidental ingestion of even one dose of morphine sulfate extended-release tablets, especially by children, can result in respiratory depression and death due to an overdose of morphine.
Neonatal Opioid Withdrawal Syndrome
Prolonged use of morphine sulfate extended-release tablets during pregnancy can result in withdrawal signs in the neonate. Neonatal opioid withdrawal syndrome, unlike opioid withdrawal syndrome in adults, may be life-threatening if not recognized and treated, and requires management according to protocols developed by neonatology experts. If opioid use is required for a prolonged period in a pregnant woman, advise the patient of the risk of neonatal opioid withdrawal syndrome and ensure that appropriate treatment will be available.
Neonatal opioid withdrawal syndrome presents as irritability, hyperactivity and abnormal sleep pattern, high pitched cry, tremor, vomiting, diarrhea and failure to gain weight. The onset, duration, and severity of neonatal opioid withdrawal syndrome vary based on the specific opioid used, duration of use, timing and amount of last maternal use, and rate of elimination of the drug by the newborn.
Interactions with Central Nervous System Depressants
Hypotension, and profound sedation, coma or respiratory depression may result if morphine sulfate extended-release tablets are used concomitantly with other central nervous system (CNS) depressants (e.g., sedatives, anxiolytics, hypnotics, neuroleptics, other opioids).
When considering the use of morphine sulfate extended-release tablets in a patient taking a CNS depressant, assess the duration of use of the CNS depressant and the patient’s response, including the degree of tolerance that has developed to CNS depression. Additionally, evaluate the patient’s use of alcohol and/or illicit drugs that cause CNS depression. If the decision to begin morphine sulfate extended-release tablets is made, start with the lowest possible dose, 15 mg every 12 hours, monitor patients for signs of sedation and respiratory depression, and consider using a lower dose of the concomitant CNS depressant [see Drug Interactions].
Use in Elderly, Cachectic, and Debilitated Patients
Life-threatening respiratory depression is more likely to occur in elderly, cachectic, or debilitated patients as they may have altered pharmacokinetics or altered clearance compared to younger, healthier patients. Monitor such patients closely, particularly when initiating and titrating morphine sulfate extended-release tablets and when morphine sulfate extended-release tablets are given concomitantly with other drugs that depress respiration [see
Warnings and Precautions
Use in Patients with Chronic Pulmonary Disease
Monitor patients with significant chronic obstructive pulmonary disease or cor pulmonale, and patients having a substantially decreased respiratory reserve, hypoxia, hypercapnia, or pre-existing respiratory depression for respiratory depression, particularly when initiating therapy and titrating with morphine sulfate extended-release tablets, as in these patients, even usual therapeutic doses of morphine sulfate extended-release tablets may decrease respiratory drive to the point of apnea [see
Warnings and Precautions
]. Consider the use of alternative non-opioid analgesics in these patients if possible.
Morphine sulfate extended-release tablets may cause severe hypotension including orthostatic hypotension and syncope in ambulatory patients. There is an increased risk in patients whose ability to maintain blood pressure has already been compromised by a reduced blood volume or concurrent administration of certain CNS depressant drugs (e.g., phenothiazines or general anesthetics) [see
]. Monitor these patients for signs of hypotension after initiating or titrating the dose of morphine sulfate extended-release tablets. In patients with circulatory shock, morphine sulfate extended-release tablets may cause vasodilation that can further reduce cardiac output and blood pressure. Avoid the use of morphine sulfate extended-release tablets in patients with circulatory shock.
Use in Patients with Head Injury or Increased Intracranial Pressure
Monitor patients taking morphine sulfate extended-release tablets who may be susceptible to the intracranial effects of CO2 retention (e.g., those with evidence of increased intracranial pressure or brain tumors) for signs of sedation and respiratory depression, particularly when initiating therapy with morphine sulfate extended-release tablets. Morphine sulfate extended-release tablets may reduce respiratory drive, and the resultant CO2 retention can further increase intracranial pressure. Opioids may also obscure the clinical course in a patient with a head injury.
Avoid the use of morphine sulfate extended-release tablets in patients with impaired consciousness or coma.
Use in Patients with Gastrointestinal Conditions
Morphine sulfate extended-release tablets are contraindicated in patients with paralytic ileus. Avoid the use of morphine sulfate extended-release tablets in patients with other GI obstruction.
The morphine in morphine sulfate extended-release tablets may cause spasm of the sphincter of Oddi. Monitor patients with biliary tract disease, including acute pancreatitis, for worsening symptoms. Opioids may cause increases in the serum amylase.
Use in Patients with Convulsive or Seizure Disorders
The morphine in morphine sulfate extended-release tablets may aggravate convulsions in patients with convulsive disorders, and may induce or aggravate seizures in some clinical settings. Monitor patients with a history of seizure disorders for worsened seizure control during morphine sulfate extended-release tablets therapy.
Avoidance of Withdrawal
Avoid the use of mixed agonist/antagonist (i.e., pentazocine, nalbuphine, and butorphanol) or partial agonist (buprenorphine) analgesics in patients who have received or are receiving a course of therapy with a full opioid agonist analgesic, morphine sulfate extended-release tablets. In these patients, mixed agonists/antagonist and partial agonist analgesics may reduce the analgesic effect and/or may precipitate withdrawal symptoms.
When discontinuing morphine sulfate extended-release tablets, gradually taper the dose [see
Dosage and Administration
]. Do not abruptly discontinue morphine sulfate extended-release tablets.
Driving and Operating Machinery
Morphine sulfate extended-release tablets may impair the mental or physical abilities needed to perform potentially hazardous activities such as driving a car or operating machinery. Warn patients not to drive or operate dangerous machinery unless they are tolerant to the effects of morphine sulfate extended-release tablets and know how they will react to the medication.
USE IN SPECIFIC POPULATIONS
Fetal/neonatal adverse reactions
Prolonged use of opioid analgesics during pregnancy for medical or nonmedical purposes can result in physical dependence in the neonate and neonatal opioid withdrawal syndrome shortly after birth. Observe newborns for symptoms of neonatal opioid withdrawal syndrome, such as poor feeding, diarrhea, irritability, tremor, rigidity, and seizures, and manage accordingly [see Warnings and Precautions].
Teratogenic Effects -Pregnancy Category C
There are no adequate and well-controlled studies in pregnant women. Morphine sulfate extended-release tablets should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
In humans, the frequency of congenital anomalies has been reported to be no greater than expected among the children of 70 women who were treated with morphine during the first four months of pregnancy or in 448 women treated with morphine anytime during pregnancy. Furthermore, no malformations were observed in the infant of a woman who attempted suicide by taking an overdose of morphine and other medication during the first trimester of pregnancy.
Several literature reports indicate that morphine administered subcutaneously during the early gestational period in mice and hamsters produced neurological, soft tissue and skeletal abnormalities. With one exception, the effects that have been reported were following doses that were maternally toxic and the abnormalities noted were characteristic of those observed when maternal toxicity is present. In one study, following subcutaneous infusion of doses greater than or equal to 0.15 mg/kg to mice, exencephaly, hydronephrosis, intestinal hemorrhage, split supraoccipital, malformed sternebrae, and malformed xiphoid were noted in the absence of maternal toxicity. In the hamster, morphine sulfate given subcutaneously on gestation day 8 produced exencephaly and cranioschisis. In rats treated with subcutaneous infusions of morphine during the period of organogenesis, no teratogenicity was observed. No maternal toxicity was observed in this study; however, increased mortality and growth retardation were seen in the offspring. In two studies performed in the rabbit, no evidence of teratogenicity was reported at subcutaneous doses up to 100 mg/kg.
Infants born to mothers who have taken opioids chronically may exhibit neonatal withdrawal syndrome [see Warnings and Precautions], reversible reduction in brain volume, small size, decreased ventilatory response to CO2 and increased risk of sudden infant death syndrome. Morphine sulfate should be used by a pregnant woman only if the need for opioid analgesia clearly outweighs the potential risks to the fetus.
Controlled studies of chronic in utero morphine exposure in pregnant women have not been conducted. Published literature has reported that exposure to morphine during pregnancy in animals is associated with reduction in growth and a host of behavioral abnormalities in the offspring. Morphine treatment during gestational periods of organogenesis in rats, hamsters, guinea pigs and rabbits resulted in the following treatment-related embryotoxicity and neonatal toxicity in one or more studies: decreased litter size, embryo-fetal viability, fetal and neonatal body weights, absolute brain and cerebellar weights, delayed motor and sexual maturation, and increased neonatal mortality, cyanosis and hypothermia. Decreased fertility in female offspring, and decreased plasma and testicular levels of luteinizing hormone and testosterone, decreased testes weights, seminiferous tubule shrinkage, germinal cell aplasia, and decreased spermatogenesis in male offspring were also observed. Decreased litter size and viability were observed in the offspring of male rats administered morphine (25 mg/kg, IP) for 1 day prior to mating. Behavioral abnormalities resulting from chronic morphine exposure of fetal animals included altered reflex and motor skill development, mild withdrawal, and altered responsiveness to morphine persisting into adulthood.
Labor and Delivery
Opioids cross the placenta and may produce respiratory depression in neonates. Morphine sulfate extended-release tablets are not for use in women during and immediately prior to labor, when shorter acting analgesics or other analgesic techniques are more appropriate. Opioid analgesics can prolong labor through actions that temporarily reduce the strength, duration, and frequency of uterine contractions. However, this effect is not consistent and may be offset by an increased rate of cervical dilatation, which tends to shorten labor.
Morphine is excreted in breast milk, with a milk to plasma morphine AUC ratio of approximately 2.5:1. The amount of morphine received by the infant varies depending on the maternal plasma concentration, the amount of milk ingested by the infant, and the extent of first pass metabolism.
Withdrawal signs can occur in breast-feeding infants when maternal administration of morphine is stopped.
Because of the potential for adverse reactions in nursing infants from morphine sulfate extended-release tablets, a decision should be made whether to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother.
The safety and effectiveness in pediatric patients below the age of 18 have not been established.
The pharmacokinetics of morphine sulfate extended-release tablets have not been studied in elderly patients. Clinical studies of morphine sulfate extended-release tablets did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.