MST Continus

Action

Interacts with opioid receptor sites, primarily in limbic system, thalamus, and spinal cord. This interaction alters neurotransmitter release, altering perception of and tolerance for pain.

Availability
morphine hydrochloride

Rectal suppositories: 20 mg, 30 mg

Syrup: 1 mg/ml, 5 mg/ml, 10 mg/ml, 20 mg/ml, 50 mg/ml

Tablets: 10 mg, 20 mg, 40 mg, 60 mg

morphine sulfate

Capsules: 15 mg, 30 mg

Capsules (extended-release): 10 mg, 20 mg, 30 mg, 50 mg, 60 mg, 80 mg, 90 mg, 100 mg, 120 mg, 200 mg

Capsules (sustained-release): 10 mg, 20 mg, 30 mg, 50 mg, 60 mg, 100 mg

Oral solution: 2 mg/ml, 4 mg/ml, 20 mg/ml (concentrate), 10 mg/5 ml, 20 mg/5 ml, 100 mg/5 ml

Rectal suppositories: 5 mg, 10 mg, 20 mg, 30 mg

Solution for epidural injection (extended-release, liposomal): 10 mg/ml, 15 mg/1.5 ml, 20 mg/2-ml vials

Solution for epidural or intrathecal use (preservative free, for continuous microinfusion device): 10 mg/ml and 25 mg/ml in 20-ml vials

Solution for epidural or I.V. injection (preservative-free): 0.5 mg/ml, 1 mg/ml

Solution for I.M., I.V., or subcutaneous injection: 1 mg/ml, 2 mg/ml, 4 mg/ml, 5 mg/ml, 8 mg/ml, 10 mg/ml, 15 mg/ml, 25 mg/ml, 50 mg/ml

Solution for I.V. injection (for patient-controlled analgesia [PCA] device): 1 mg/ml, 2 mg/ml, 3 mg/ml, 5 mg/ml

Tablets: 15 mg, 30 mg

Tablets (controlled-release, sustained-release): 15 mg, 30 mg, 60 mg, 100 mg, 200 mg

Tablets (soluble): 10 mg, 15 mg, 30 mg

Indications and dosages

➣ Severe to moderate pain

Oral use-

Adults: 5 to 30 mg P.O. (immediate-release) q 4 hours p.r.n. Or 20 mg P.O. (controlled-release, Kadian) once or twice daily p.r.n. Or 200 mg P.O. (MS Contin) in opioid-tolerant patients who require daily morphine-equivalent dosages above 400 mg.

I.M. or subcutaneous use-

Adults: 5 to 20 mg/70 kg I.M. or subcutaneously q 4 hours p.r.n.

I.V. use-

Adults: 2 to 10 mg/70 kg I.V. p.r.n. given slowly over 4 to 5 minutes. As a continuous I.V. infusion, 0.1 to 1 mg/ml in dextrose 5% in water delivered by controlled-infusion device.

Rectal use-

Adults: 10 to 30 mg P.R. q 4 hours p.r.n.

Epidural use-

Adults: Initially 5 mg (Astramorph PF, Duramorph) injected in lumbar region (may relieve pain up to 24 hours). If response isn't adequate within 1 hour, carefully give incremental doses of 1 to 2 mg p.r.n., up to 10 mg/24 hours. For continuous epidural infusion, 2 to 4 mg/24 hours. For epidural injection (DepoDur) before orthopedic leg surgery, recommended dosage is 15 mg; before lower abdominal or pelvic surgery, 10 to 15 mg. For cesarean section after umbilical cord clamping, recommended dosage is 10 mg.

Intrathecal use-

Adults: Usual intrathecal dosage is one-tenth of epidural dosage; 0.2 to 1 mg as a single injection in lumbar area may relieve pain up to 24 hours.

Dosage adjustment

• Adults weighing less than 50 kg (110 lb)

• Elderly patients

• Children

Contraindications

• Hypersensitivity to drug, tartrazine, bisulfites, or alcohol

• Acute bronchial asthma

• Upper airway obstruction

• Respiratory depression

• GI obstruction, paralytic ileus

Precautions

Use cautiously in:

• head trauma; increased intracranial pressure; severe renal, hepatic, or pulmonary disease; hypothyroidism; adrenal insufficiency; prostatic hypertrophy

• elderly or debilitated patients

• pregnant or breastfeeding patients.

Administration

• For best response, give at pain onset.

• Give oral form with food or milk to minimize GI upset.

• If desired, crush immediate-release form and mix with food or fluids.

• Don't crush or break extended-release form; remind patient to swallow it whole.

• If desired, open sustained-release capsules (Kadian) and sprinkle entire contents onto small amount of food (such as applesauce). Have patient consume mixture immediately without chewing, crushing, or dissolving pellets.

• When giving by direct I.V., dilute in at least 5 ml of sterile water for injection or normal saline solution. Give 2.5 to 10 mg over 4 to 5 minutes.

• For continuous I.V. infusion, use infusion pump or PCA pump. Titrate dosage to provide adequate pain relief.

• Don't use parenteral form if it's cloudy or contains visible particulates.

Adverse reactions

CNS: confusion, sedation, dizziness, dysphoria, euphoria, floating feeling, hallucinations, headache, nightmares

CV: hypotension, bradycardia

EENT: blurred vision, diplopia, miosis

GI: nausea, vomiting, constipation, dry mouth

GU: urinary retention

Respiratory: apnea, respiratory depression, respiratory arrest

Skin: flushing, itching, sweating

Other: physical or psychological drug dependence, drug tolerance

Interactions

Drug-drug. Antihistamines, barbiturates, clomipramine, sedative-hypnotics, tricyclic antidepressants: additive CNS depression

Buprenorphine, butorphanol, dezocine, nalbuphine, pentazocine: decreased analgesia

Cimetidine: decreased morphine metabolism and increased effects

MAO inhibitors: severe, unpredictable reactions

Mixed opioid agonist-antagonists: precipitation of withdrawal symptoms in physically dependent patients

Warfarin: increased anticoagulant effect

Drug-diagnostic tests. Amylase, lipase: increased levels

Drug-herbs. Chamomile, hops, kava, skullcap, valerian: increased CNS depression

Drug-behaviors. Alcohol use: increased CNS depression

Patient monitoring

• Monitor vital signs. Contact prescriber if respiratory rate is 10 breaths/minute or less.

• Assess pain character, location, and intensity.

• Monitor fluid intake and output. Stay alert for urinary retention.

• Monitor bowel elimination pattern. If constipation occurs, intervene as appropriate.

• Assess neurologic status. Implement safety measures as needed to prevent injury.

• Evaluate patient for signs and symptoms of physical or psychological dependence. Be watchful for drug hoarding.

Patient teaching

• Tell patient he may crush immediate-release form and mix with food or fluids.

• Advise patient not to crush or break extended-release form. Instruct him to swallow it whole.

• Tell patient he may open sustained-release capsule (Kadian), sprinkle entire contents of capsule onto a small amount of food (such as applesauce), and consume immediately. Stress importance of not chewing, crushing, or dissolving pellets.

• Advise patient to take drug at the first sign of pain, because continuous dosing is more effective than p.r.n. dosing.

See Tell patient and caregiver that drug may cause respiratory depression. Instruct them to immediately report respiratory rate of 10 breaths/minute or less.

• Inform patient that drug may cause constipation or urinary retention. Encourage high-fiber diet and high fluid intake.

• Stress importance of taking drug only as prescribed. Point out that drug may cause psychological or physical dependence.

• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration, vision, and alertness.

• Teach patient and caregiver about appropriate safety measures to prevent injury.

• Caution patient to avoid alcohol and other CNS depressants during and for 24 hours after therapy.

• Advise patient to avoid herbs, which may worsen adverse CNS effects.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, herbs, and behaviors mentioned above.