OxyContin

Action

Unknown. Thought to interact with opioid receptor sites primarily in limbic system, thalamus, and spinal cord, blocking transmission of pain impulses.

Availability

Capsules (immediate-release): 5 mg

Solution (oral): 5 mg/5 ml

Tablets: 5 mg, 7.5 mg, 10 mg, 15 mg, 20 mg, 30 mg

Tablets (controlled-release): 10 mg, 15 mg, 20 mg, 30 mg, 40 mg, 60 mg, 80 mg

Indications and dosages

➣ Moderate to severe pain

Adults: 5 mg P.O. q 6 hours p.r.n., increased gradually to 10 to 30 mg q 6 hours p.r.n.

➣ Moderate or severe pain when continuous around-the-clock analgesia is needed

Adults: 10 mg P.O. (controlled-release) q 12 hours. For patients already taking opioids, use total oral oxycodone daily equianalgesic dosage and then round down to closest tablet strength. For breakthrough pain, give supplemental immediate-release doses.

Dosage adjustment

• Hepatic disease

• Renal impairment

• Debilitated or opioid-naive patients

Off-label uses

• Postherpetic neuralgia (controlled release form)

Contraindications

• Hypersensitivity to drug

• Paralytic ileus

• When opioids are contraindicated (as in respiratory depression, severe bronchial asthma, hypercarbia)

Precautions

Use cautiously in:

• head trauma; increased intracranial pressure (ICP); severe renal, hepatic, or pulmonary disease; hypothyroidism; adrenal insufficiency; urethral stricture; undiagnosed abdominal pain or prostatic hyperplasia; extensive burns; alcoholism

• history of substance abuse

• prolonged or high-dose therapy

• elderly or debilitated patients

• labor and delivery

• pregnant or breastfeeding patients

• children younger than age 18.

Administration

• Be aware that drug has high abuse potential.

• Know that controlled-release Oxy-Contin isn't indicated for p.r.n. pain control but is reserved for patients who need continuous, around-the-clock analgesia.

• Be aware that 80-mg controlled-release tablets are for opioid-tolerant patients only.

☞ Never break, crush, or let patient chew controlled-release forms. Otherwise, rapid release and absorption of potentially fatal dose may occur.

• Give Oxecta tablets whole. Don't crush or dissolve tablets or administer by nasogastric, gastric, or other feeding tubes, because this may cause obstruction of feeding tubes.

• When discontinuing, taper dosage gradually to prevent withdrawal symptoms.

Adverse reactions

CNS: dizziness, asthenia, drowsiness, euphoria, light-headedness, insomnia, confusion, anxiety, twitching, abnormal dreams and thoughts

CV: orthostatic hypotension, circulatory depression, bradycardia, shock

GI: nausea, vomiting, constipation, diarrhea, ileus, abdominal pain, dyspepsia, gastritis, anorexia

GU: urinary retention

Respiratory: apnea, respiratory depression, respiratory arrest

Skin: pruritus, sweating

Other: chills, fever, hiccups, physical and psychological drug dependence

Interactions

Drug-drug. Antihistamines, sedative-hypnotics: additive CNS depression

Barbiturates, protease inhibitors: increased respiratory and CNS depression

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

Drug-diagnostic tests. Amylase, lipase: increased levels

Drug-behaviors. Alcohol use: additive CNS depression

Patient monitoring

☞ Monitor vital signs and respiratory status. Withhold drug in significant respiratory or CNS depression.

• Assess patient's pain level frequently.

• Monitor bowel and bladder function.

• Assess patient for anxiety, twitching, and other CNS symptoms.

• Closely monitor head-trauma patient. Drug may increase ICP while masking signs and symptoms.

• Carefully assess patient with acute abdominal pain. Drug may obscure diagnosis.

• Stay alert for drug hoarding, tolerance, and dependence.

Patient teaching

☞ Caution patient not to break, crush, chew, or dissolve controlled-release tablets. Warn him that doing so may cause rapid drug release and absorption (possibly fatal).

• Tell patient taking controlled-release form not to drive for 3 to 4 days after dosage increase, after consuming even a single alcoholic beverage, or if also taking antihistamines or other drugs that cause drowsiness.

• Tell patient to take Oxecta tablets whole.

☞ Instruct patient to promptly report adverse reactions, especially difficulty breathing or slow pulse.

• Advise patient not to drink alcohol.

• Tell patient not to be alarmed if controlled-release tablets appear in stools; drug has already been absorbed.

• Advise ambulatory patient to change position slowly, to avoid dizziness from orthostatic hypotension.

• Instruct patient to consult prescriber before taking other drugs.

• Caution patient to avoid driving and other hazardous activities, because drug may cause drowsiness or dizziness.

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