M O S Side Effects

Generic name: morphine

Medically reviewed by Drugs.com. Last updated on May 7, 2024.

Note: This document provides detailed information about M O S Side Effects associated with morphine. Some dosage forms listed on this page may not apply specifically to the brand name M O S.

Applies to morphine: oral capsule extended release, oral capsule extended release 24 hr, oral solution, oral tablet, oral tablet extended release.

Other dosage forms:

• injection solution

Important warnings This medicine can cause some serious health issues

Oral route (capsule, extended release; solution; tablet; tablet, extended release)

Addiction, Abuse, and Misuse. Morphine sulfate exposes users to risks of addiction, abuse, and misuse, which can lead to overdose and death.

Assess each patient’s risk before prescribing, and monitor regularly for these behaviors and conditions.Opioid Analgesic Risk Evaluation and Mitigation Strategy (REMS)To ensure that the benefits of opioid analgesics outweigh the risks of addiction, abuse, and misuse, the Food and Drug Administration (FDA) has required a Risk Evaluation and Mitigation Strategy (REMS) for these products.Life-Threatening Respiratory Depression. Serious, life-threatening or fatal respiratory depression may occur.

Monitor closely, especially upon initiation or following a dose increase.

Instruct patients to swallow morphine sulfate whole to avoid exposure to a potentially fatal dose of morphine.Accidental Ingestion. Accidental ingestion of morphine sulfate, especially in children, can result in fatal overdose of morphine.Neonatal Opioid Withdrawal Syndrome. Prolonged use of morphine sulfate during pregnancy can result in neonatal opioid withdrawal syndrome, which may be life-threatening if not recognized and treated.

If prolonged opioid use is required in a pregnant woman, advise the patient of the risk of neonatal opioid withdrawal syndrome and ensure that appropriate treatment will be available.Risks From Concomitant Use With Benzodiazepines or Other CNS Depressants. Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death.

Reserve concomitant prescribing for use in patients for whom alternative treatment options are inadequate; limit dosages and durations to the minimum required; and follow patients for signs and symptoms of respiratory depression and sedation.

Common side effects of M O S

Some side effects of morphine may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

• cramps
• difficulty having a bowel movement
• drowsiness
• false or unusual sense of well-being
• relaxed and calm feeling
• sleepiness or unusual drowsiness
• weight loss

Less common

• absent, missed, or irregular menstrual periods
• bad, unusual, or unpleasant (after) taste
• change in vision
• dry mouth
• floating feeling
• halos around lights
• heartburn or indigestion
• loss in sexual ability, desire, drive, or performance
• muscle stiffness or tightness
• night blindness
• overbright appearance of lights
• problems with muscle control
• stomach discomfort or upset
• trouble sleeping
• uncontrolled eye movements

Incidence not known

• abnormal dreams
• change in walking and balance
• change or problem with discharge of semen
• clumsiness or unsteadiness
• confusion as to time, place, or person
• false beliefs that cannot be changed by facts
• feeling of constant movement of self or surroundings
• general feeling of discomfort or illness
• holding false beliefs that cannot be changed by fact
• poor insight and judgment
• problems with memory or speech
• seeing, hearing, or feeling things that are not there
• sensation of spinning
• trouble recognizing objects
• trouble thinking and planning
• trouble walking
• unusual excitement, nervousness, or restlessness

Serious side effects of M O S

Along with its needed effects, morphine (the active ingredient contained in M O S) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking morphine:

Less common

• blurred vision
• bulging soft spot on the head of an infant
• burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
• change in the ability to see colors, especially blue or yellow
• chest pain or discomfort
• chills
• confusion
• cough
• decreased urination
• dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
• fainting
• fast, pounding, or irregular heartbeat or pulse
• headache
• hives, itching, or skin rash
• increased sweating
• loss of appetite
• nausea
• nervousness
• pounding in the ears
• puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
• severe constipation
• severe vomiting
• shakiness in the legs, arms, hands, or feet
• slow heartbeat
• stomach pain
• sweating
• vomiting

Incidence not known

• agitation
• black, tarry stools
• cold, clammy skin
• darkening of the skin
• diarrhea
• difficulty swallowing
• feeling of warmth or heat
• fever
• flushing or redness of the skin, especially on the face and neck
• irregular, fast or slow, or shallow breathing
• lightheadedness
• loss of consciousness
• low blood pressure or pulse
• mental depression
• overactive reflexes
• painful urination
• pale or blue lips, fingernails, or skin
• pale skin
• pinpoint red spots on the skin
• poor coordination
• pounding in the ears
• puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
• restlessness
• shakiness and unsteady walk
• shivering
• talking or acting with excitement you cannot control
• tightness in the chest
• twitching
• unsteadiness, trembling, or other problems with muscle control or coordination
• unusual bleeding or bruising
• unusual tiredness or weakness
• very slow heartbeat

Get emergency help immediately if any of the following symptoms of overdose occur while taking morphine:

Symptoms of overdose

• constricted, pinpoint, or small pupils (black part of the eye)
• decreased awareness or responsiveness
• extreme drowsiness
• fever
• increased blood pressure
• increased thirst
• lower back or side pain
• muscle cramps, spasms, pain, or stiffness
• no muscle tone or movement
• severe sleepiness
• swelling of the face, fingers, or lower legs
• weight gain

For healthcare professionals

Applies to morphine: compounding powder, injectable solution, injectable tablet soluble, intramuscular solution, intravenous solution, oral capsule, oral capsule extended release, oral concentrate, oral liquid, oral solution, oral tablet, oral tablet extended release, rectal suppository, spinal solution.

Nervous system

• Very common (10% or more): Drowsiness (28%)
• Common (1% to 10%): Dizziness, sedation, fever, anxiety, confusion, tremor, diaphoresis, lethargy, feeling of warmth
• Uncommon (0.1% to 1%): Withdrawal symptoms after either abrupt cessation or fast tapering of the drug, headache, chills, flu syndrome, malaise, withdrawal syndrome, pallor, facial flushing, syncope, loss of concentration, insomnia, amnesia, paresthesia, agitation, vertigo, foot drop, ataxia, hypesthesia, slurred speech, hallucinations, euphoria, apathy, seizures, myoclonus
• Frequency not reported: Inflammatory masses including granulomas (some of which have resulted in serous neurologic impairment including paralysis) in patients receiving continuous infusion of opioids via indwelling intrathecal catheter^[Ref]

Central nervous system side effects may be either depressant or excitatory. Excitatory symptoms are sometimes ignored as possible side effects of morphine. Severe adverse effects such as respiratory depression can be treated with the opioid antagonist naloxone.

Patients receiving continuous infusion of morphine sulfate via indwelling intrathecal catheter should be monitored for new neurologic signs or symptoms. Further assessment or intervention should be based on the clinical condition of the individual patient.

Myoclonic spasms may occur in patients receiving high dose morphine, particularly in the setting of renal dysfunction. Hyperalgesia has also been reported with high doses.^[Ref]

Respiratory

• Common (1% to 10%): Respiratory depression
• Uncommon (0.1% to 1%): Hiccup, rhinitis, atelectasis, asthma, hypoxia, voice alteration, depressed cough reflex, noncardiogenic pulmonary edema, bronchospasm^[Ref]

Gastrointestinal

• Common (1% to 10%): Dry mouth, constipation, nausea, diarrhea, anorexia, abdominal pain, vomiting
• Uncommon (0.1% to 1%): Dysphagia, dyspepsia, stomach atony disorder, gastroesophageal reflux, delayed gastric emptying, biliary colic, increased gastroesophageal reflux, intestinal obstruction^[Ref]

Morphine may cause constriction of the common bile duct and spasm of the sphincter of Oddi, thereby increasing intrabiliary pressure and worsening, rather than relieving, biliary colic.

In addition, morphine may cause intense but uncoordinated duodenal contraction and decreased gastric emptying.^[Ref]

Cardiovascular

• Common (1% to 10%): Chest pain
• Uncommon (0.1% to 1%): Tachycardia, atrial fibrillation, hypertension, hypotension, palpitations, bradycardia, vasodilation^[Ref]

Psychiatric

• Uncommon (0.1% to 1%): Abnormal thinking, abnormal dreams, depression, fearfulness, agitation, paranoia, psychosis, hypervigilance, hallucinations, delirium
• Frequency not reported: Withdrawal symptoms after abrupt cessation of therapy^[Ref]

Genitourinary

• Uncommon (0.1% to 1%): Urinary abnormality, urinary retention, urinary hesitancy^[Ref]

The risk of acute urinary retention is very high when morphine is administered by epidural or intrathecal injection. Clinicians should be attentive to the increased risk of urosepsis in this setting, particularly if instrumentation of the urinary tract is necessary.^[Ref]

Hematologic

• Common (1% to 10%): Anemia, leukopenia
• Uncommon (0.1% to 1%): Thrombocytopenia^[Ref]

Endocrine

• Uncommon (0.1% to 1%): Hyponatremia due to inappropriate ADH secretion, gynecomastia, amenorrhea, reduced libido, reduced potency, prolonged labor^[Ref]

Musculoskeletal

• Common (1% to 10%): Asthenia, accidental injury
• Uncommon (0.1% to 1%): Back pain, bone pain, arthralgia
• Frequency not reported: Opioid-induced involuntary muscle hyperactivity with chronic high doses^[Ref]

Dermatologic

• Common (1% to 10%): Rash
• Uncommon (0.1% to 1%): Decubitus ulcer, pruritus, skin flush^[Ref]

Ocular

• Uncommon (0.1% to 1%): Amblyopia, conjunctivitis, miosis, blurred vision, nystagmus, diplopia^[Ref]

Hypersensitivity

• Very rare (less than 0.01%): Hypersensitivity reactions, anaphylaxis^[Ref]

Hepatic

• Uncommon (0.1% to 1%): Increases in hepatic enzymes^[Ref]

Metabolic

• Common (1% to 10%): Peripheral edema
• Uncommon (0.1% to 1%): Hyponatremia

Frequently asked questions

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Further information

M O S side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.

Medical Disclaimer