Morphine Sulfate (Page 3 of 9)

5.8 Severe Hypotension

Morphine sulfate suppositories may cause severe hypotension including orthostatic hypotension and syncope in ambulatory patients. There is 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 Drug Interactions (7)]. Monitor these patients for signs of hypotension after initiating or titrating the dosage of morphine sulfate suppositories. In patients with circulatory shock, morphine sulfate suppositories may cause vasodilation that can further reduce cardiac output and blood pressure. Avoid the use of morphine sulfate suppositories in patients with circulatory shock.

5.9 Risks of use in Patients with Increased Intracranial Pressure, Brain Tumors, Head Injury, or Impaired Consciousness

In patients who may be susceptible to the intracranial effects of CO2 retention (e.g., those with evidence of increased intracranial pressure or brain tumors), morphine sulfate suppositories may reduce respiratory drive, and the resultant CO2 retention can further increase intracranial pressure. Monitor such patients for signs of sedation and respiratory depression, particularly when initiating therapy with morphine sulfate suppositories.

Opioids may also obscure the clinical course in a patient with a head injury. Avoid the use of morphine sulfate suppositories in patients with impaired consciousness or coma.

5.10 Risks of Use in Patients with Gastrointestinal Conditions

Morphine sulfate suppositories is contraindicated in patients with known or suspected gastrointestinal obstruction, including paralytic ileus. The morphine in morphine sulfate suppositories may cause spasm of the sphincter of Oddi. Opioids may cause increases in serum amylase. Monitor patients with biliary tract disease, including acute pancreatitis, for worsening symptoms.

5.11 Increased Risk of Seizures in Patients with Seizure Disorders

The morphine in morphine sulfate suppositories may increase the frequency of seizures in patients with seizure disorders, and may increase the risk of seizures occurring in other clinical settings associated with seizures. Monitor patients with a history of seizure disorders for worsened seizure control during morphine sulfate suppositories therapy.

5.12 Withdrawal

Avoid the use of mixed agonist/antagonist (e.g., pentazocine, nalbuphine, and butorphanol) or partial agonist (e.g., buprenorphine) analgesics in patients who are receiving a full opioid agonist analgesic, including morphine sulfate suppositories. In these patients, mixed agonist/antagonist and partial agonist analgesics may reduce the analgesic effect and/or precipitate withdrawal symptoms [see Drug Interactions (7)].

When discontinuing morphine sulfate suppositories, gradually taper the dosage [see Dosage and Administration (2.4)]. Do not abruptly discontinue morphine sulfate suppositories [see Drug Abuse and Dependence (9.3)].

5.13 Risks of Driving and Operating Machinery

Morphine sulfate suppositories 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 suppositories and know how they will react to the medication [see Patient Counseling Information (17)].


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)]
Neonatal Opioid Withdrawal Syndrome [see Warnings and Precautions (5.3)]
Interactions with Benzodiazepine or Other CNS Depressants [see Warnings and Precautions (5.4)]
Adrenal Insufficiency [see Warnings and Precautions (5.7)]
Severe Hypotension [see Warnings and Precautions (5.8)]
Gastrointestinal Adverse Reactions [see Warnings and Precautions (5.10)]
Seizures [see Warnings and Precautions (5.11)]
Withdrawal [see Warnings and Precautions (5.12)]

The following adverse reactions associated with the use of morphine were identified in clinical studies or postmarketing reports. Because some of these reactions were reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Serious adverse reactions associated with morphine use included: respiratory depression, apnea, and to a lesser degree, circulatory depression, respiratory arrest, shock and cardiac arrest.

The common adverse reactions seen on initiation of therapy with morphine were dose-dependent and were typical opioid-related adverse reactions. The most frequent of these included constipation, nausea, and somnolence. Other commonly observed adverse reactions included: lightheadedness, dizziness, sedation, vomiting, and sweating. The frequency of these events depended upon several factors including clinical setting, the patient’s level of opioid tolerance, and host factors specific to the individual.

Other less frequently observed adverse reactions from opioid analgesics, including morphine sulfate included:

Body as a Whole: malaise, withdrawal syndrome

Cardiovascular System: bradycardia, hypertension, hypotension, palpitations, syncope, tachycardia

Digestive System: anorexia, biliary pain, dyspepsia, dysphagia, gastroenteritis, abnormal liver function tests, rectal disorder, thirst

Endocrine: hypogonadism

Hemic and Lymphatic System: anemia, thrombocytopenia

Metabolic and Nutritional Disorders: edema, weight loss

Musculoskeletal: skeletal muscle rigidity, decreased bone mineral density

Nervous System: abnormal dreams, abnormal gait, agitation, amnesia, anxiety, ataxia, confusion, convulsions, coma, delirium, depression, dry mouth, euphoria, hallucinations, lethargy, nervousness, abnormal thinking, tremor, vasodilation, vertigo, headache

Respiratory System: hiccup, hypoventilation, voice alteration

Skin and Appendages: dry skin, urticaria, pruritus

Special Senses: amblyopia, eye pain, taste perversion

Urogenital System: abnormal ejaculation, dysuria, impotence, decreased libido, oliguria, urinary retention or hesitancy, anti-diuretic effect, amenorrhea

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 suppositories.

Androgen Deficiency: Cases of androgen deficiency have occurred with chronic use of opioids [see Clinical Pharmacology (12.2)].


Table 1 includes clinically significant drug interactions with morphine sulfate suppositories.

Table 1: Clinically Significant Drug Interactions with Morphine Sulfate Suppositories

Alcohol, 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.


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. Follow patients closely for signs of respiratory depression and sedation [see Warnings and Precautions (5.4)].


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.


If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation and dose adjustment. Discontinue morphine sulfate suppositories if serotonin syndrome is suspected.


Selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), triptans, 5-HT3 receptor antagonists, drugs that effect the serotonin neurotransmitter system (e.g., mirtazapine, trazodone, tramadol), 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 (5.2, 5.6)]


Do not use morphine sulfate suppositories in patients taking MAOIs or within 14 days of stopping such treatment.


phenelzine, tranylcypromine, linezolid

Mixed Agonist/Antagonist and Partial Agonist Opioid Analgesics

Clinical Impact:

May reduce the analgesic effect of morphine sulfate suppositories and/or precipitate withdrawal symptoms.


Avoid concomitant use.


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.


Monitor patients for signs of respiratory depression that may be greater than otherwise expected and decrease the dosage of morphine sulfate suppositories and/or the muscle relaxant as necessary.


Clinical Impact:

The concomitant use of morphine and cimetidine has been reported to precipitate apnea, confusion, and muscle twitching in an isolated report.


Monitor patients for increased respiratory and CNS depression when morphine sulfate suppositories are used concomitantly with cimetidine.


Clinical Impact:

Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone.


Monitor 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.


Monitor patients for signs of urinary retention or reduced gastric motility when morphine sulfate suppositories are used concomitantly with anticholinergic drugs.

P-Glycoprotein (P-gp) Inhibitors

Clinical Impact:

The concomitant use of P-gp inhibitors can increase the exposure to morphine by twofold and can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death.


Monitor patients for signs of respiratory depression that may be greater than otherwise expected and decrease the dosage of morphine sulfate suppositories and/or the P-gp inhibitor as necessary.


quinidine, verapamil

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