Skip to Content

Infumorph Side Effects

Generic Name: morphine

Note: This document contains side effect information about morphine. Some of the dosage forms listed on this page may not apply to the brand name Infumorph.

For the Consumer

Applies to morphine: oral capsule, oral capsule delayed release, oral capsule extended release, oral capsule extended release 24 hr, oral powder for suspension extended release, oral solution, oral syrup, oral tablet, oral tablet extended release

Along with its needed effects, morphine (the active ingredient contained in Infumorph) 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
  • Abdominal or stomach pain
  • 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
  • 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 or vomiting
  • 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
  • sweating or chills
Incidence not known
  • Black, tarry stools
  • cold, clammy skin
  • feeling of warmth or heat
  • 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
  • painful urination
  • pale or blue lips, fingernails, or skin
  • pale skin
  • pinpoint red spots on the skin
  • pounding in the ears
  • shakiness and unsteady walk
  • unsteadiness, trembling, or other problems with muscle control or coordination
  • unusual bleeding or bruising
  • 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 or spasms
  • muscle pain or stiffness
  • no muscle tone or movement
  • severe sleepiness
  • swelling of the face, fingers, or lower legs
  • weight gain

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 (stool)
  • 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
  • agitation
  • bad, unusual, or unpleasant (after) taste
  • change in vision
  • depression
  • dry mouth
  • face is warm or hot to touch
  • 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
  • redness of the skin
  • skin rash
  • 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
  • delusions
  • dementia
  • feeling of constant movement of self or surroundings
  • general feeling of discomfort or illness
  • holding false beliefs that cannot be changed by fact
  • problems with memory
  • seeing, hearing, or feeling things that are not there
  • sensation of spinning
  • unusual excitement, nervousness, or restlessness

For Healthcare Professionals

Applies to morphine: compounding powder, injectable solution, injectable tablet soluble, 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

Central nervous system side effects may be either depressant or excitatory. Excitatory symptoms are sometimes ignored as possible side effects of morphine (the active ingredient contained in Infumorph) 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]

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]


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]


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 (the active ingredient contained in Infumorph) may cause intense but uncoordinated duodenal contraction and decreased gastric emptying.[Ref]

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]


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


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]


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]


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


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


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]


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


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


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


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


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


1. Morley JS, Watt JWG, Wells JC, Miles JB, Finnegan MJ, Leng G "Methadone in pain uncontrolled by morphine." Lancet 342 (1993): 1243

2. Littrell RA, Kennedy LD, Birmingham WE, Leak WD "Muscle spasms associated with intrathecal morphine therapy: treatment with midazolam." Clin Pharm 11 (1992): 57-9

3. Covington EC, Gonsalves-Ebrahim L, Currie KO, et al "Severe respiratory depression from patient-controlled analgesia in renal failure." Psychosomatics 30 (1989): 226-8

4. Bellville JW, Forrest WH, Elashoff J, Laska E "Evaluating side effects of analgesics in a cooperative clinical study." Clin Pharmacol Ther 9 (1968): 303-13

5. Westerling D, Frigren L, Hoglund P "Morphine pharmacokinetics and effects on salivation and continuous reaction times in healthy volunteers." Ther Drug Monit 15 (1993): 364-74

6. Sjogren P, Dragsted L, Christensen CB "Myoclonic spasms during treatment with high doses of intravenous morphine in renal failure." Acta Anaesthesiol Scand 37 (1993): 780-2

7. Sylvester RK, Levitt R, Steen PD "Opioid-induced muscle activity: implications for managing chronic pain." Ann Pharmacother 29 (1995): 1118-21

8. Sjogren P, Jonsson T, Jensen NH, Drenck NE, Jensen TS "Hyperalgesia and myoclonus in terminal cancer patients treated with continuous intravenous morphine." Pain 55 (1993): 93-7

9. Etches RC "Respiratory depression associated with patient-controlled analgesia - a review of eight cases." Can J Anaesth 41 (1994): 125-32

10. Bigler D, Eriksen J, Christensen CB "Prolonged respiratory depression caused by slow release morphine." Lancet 06/30/84 (1984): 1477

11. Kwan A "Morphine overdose from patient-controlled analgesia pumps." Anaesth Intensive Care 24 (1996): 254-6

12. Chambers FA, Mccarroll M, Macsullivan R "Polyarthralgia and amenorrhoea as a complication of intrathecally infused morphine and dilaudid in the treatment of chronic benign back pain." Br J Anaesth 72 (1994): 734

13. Ogawa K, Iranami H, Yoshiyama T, Maeda H, Hatano Y "Severe respiratory depression after epidural morphine in a patient with myotonic dystrophy." Can J Anaesth 40 (1993): 968-70

14. Houghton IT, Aun CST, Wong YC, Chan K, Lau JTF, Oh TE "The respiratory depressant effect of morphine - a comparative study in three ethnic groups." Anaesthesia 49 (1994): 197-201

15. Patt RB, Wu C, Bressi J, Catania JA "Accidental intraspinal overdose revisited." Anesth Analg 76 (1993): 202

16. Morley AD "Profound respiratory depression with morphine patient-controlled analgesia in an elderly patient." Anaesth Intensive Care 24 (1996): 287

17. "Product Information. Roxanol (morphine)." Roxane Laboratories Inc, Columbus, OH.

18. Thorn SE, Wattwil M, Kallander A "Effects of epidural morphine and epidural bupivacaine on gastroduodenal motility during the fasted state and after food intake." Acta Anaesthesiol Scand 38 (1994): 57-62

19. Zsigmond EK, Vieira ZEG, Duarte B, Renigers SA, Hirota K "Double-blind placebo-controlled ultrasonographic confirmation of constriction of the common bile duct by morphine." Int J Clin Pharmacol Ther Toxicol 31 (1993): 506-9

20. Lang DW, Pilon RN "Naloxone reversal of morphine-induced biliary colic." Anesth Analg 59 (1980): 619-20

21. White MJ, Berghausen EJ, Dumont SW, et al "Side effects during continuous epidural infusion of morphine and fentanyl." Can J Anaesth 39 (1992): 576-82

22. Semenkovich CF, Jaffe AS "Adverse effects due to morphine sulfate: challenge to previous clinical doctrine." Am J Med 79 (1985): 325-30

23. D'Souza M "Unusual reaction to morphine." Lancet 07/11/87 (1987): 98

24. Christie JM, Meade WR, Markowsky S "Paranoid psychosis after intrathecal morphine." Anesth Analg 77 (1993): 1298-9

25. Petersen TK, Husted SE, Rybro L, et al "Urinary retention during I.M. and extradural morphine analgesia." Br J Anaesth 54 (1982): 1175-8

26. Petros JG, Mallen JK, Howe K, Rimm EB, Robillard RJ "Patient-controlled analgesia and postoperative urinary retention after open appendectomy." Surg Gynecol Obstet 177 (1993): 172-5

27. Cimo PL, Hammond JJ, Moake JL "Morphine-induced immune thrombocytopenia." Arch Intern Med 142 (1982): 832-4

28. Paice JA, Penn RD "Amenorrhea associated with intraspinal morphine." J Pain Symptom Manage 10 (1995): 582-3

29. Kardaun SH, de Monchy JG "Acute generalized exanthematous pustulosis caused by morphine, confirmed by positive patch test and lymphocyte transformation test." J Am Acad Dermatol 55(2 Suppl) (2006): S21-3

30. Galea M "Morphine-induced pruritus after spinal anaesthesia." Br J Anaesth 97 (2006): 426

31. Goldstein JH "Effects of drugs on cornea, conjunctiva, and lids." Int Ophthalmol Clin 11 (1971): 13-34

32. Knaggs RD, Crighton IM, Cobby TF, Fletcher AJ, Hobbs GJ "The pupillary effects of intravenous morphine, codeine, and tramadol in volunteers." Anesth Analg 99 (2004): 108-12

33. Olsen GD, Bennett WM, Porter GA "Morphine and phenytoin binding to plasma proteins in renal and hepatic failure." Clin Pharmacol Ther 17 (1975): 677-84

34. Hasselstrom J, Eriksson S, Persson A, Rane A, Svensson JO, Sawe J "The metabolism and bioavailability of morphine in patients with severe liver cirrhosis." Br J Clin Pharmacol 29 (1990): 289-97

Some side effects of Infumorph may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.