OxyContin Dosage

2.1  Safe Administration Instructions

OxyContin tablets must be swallowed whole and must not be cut, broken, chewed, crushed or dissolved. Taking cut, broken, chewed, crushed or dissolved OxyContin tablets leads to rapid release and absorption of a potentially fatal dose of oxycodone.

​OxyContin tablets should be taken one tablet at a time. Take each tablet with enough water to ensure complete swallowing immediately after placing in the mouth [see Patient Counseling Information (17.1)].

Selection of patients for treatment with OxyContin should be governed by the same principles that apply to the use of similar opioid analgesics. Physicians should individualize treatment using a progressive plan of pain management such as outlined by the World Health Organization, Federation of State Medical Boards Model Policy, and the American Pain Society.  Healthcare professionals should follow appropriate pain management principles of careful assessment and ongoing monitoring.

2.2  Initiating Therapy with OxyContin

It is critical to initiate the dosing regimen for each patient individually.  Attention should be given to:

• risk factors for abuse or addiction; including whether the patient has a previous or current substance abuse problem, a family history of substance abuse, or a history of mental illness or depression;
• the age, general condition and medical status of the patient;
• the patient's opioid exposure and opioid tolerance (if any);
• the daily dose, potency, and kind of the analgesic(s) the patient has been taking;
• the reliability of the conversion estimate used to calculate the dose of oxycodone;
• the special instructions for OxyContin  60 mg and 80 mg tablets, a single dose greater than 40 mg, or total daily doses greater than 80 mg [see Dosage and Administration (2.7)]; and
• the balance between pain control and adverse reactions.

Use low initial doses of OxyContin in patients who are not already opioid-tolerant [see Dosage and Administration (2.7)], especially those who are receiving concurrent treatment with muscle relaxants, sedatives, or other CNS active medications [see Warnings and Precautions (5.1, 5.3) and Drug Interactions (7.1, 7.3)].

Experience indicates a reasonable starting dose of OxyContin for patients who are taking non-opioid analgesics and require continuous around-the-clock therapy for an extended period of time is 10 mg every 12 hours.  Individually titrate OxyContin to a dose that provides adequate analgesia and minimizes adverse reactions while maintaining an every-twelve-hour dosing regimen.

For initiation of OxyContin therapy for patients previously taking opioids, the conversion ratios found in Table 1 are a reasonable starting point, although not verified in well-controlled, multiple-dose trials. No fixed conversion ratio is likely to be satisfactory in all patients, especially patients receiving large opioid doses.  A reasonable approach for converting from existing opioid therapy to OxyContin is as follows:

• Discontinue all other around-the-clock opioid drugs when OxyContin therapy is initiated.
• Using standard conversion ratio estimates (see Table 1), multiply the mg/day of each of the current opioids to be converted by their appropriate multiplication factor to obtain the equivalent total daily dose of oral oxycodone.
• Divide the calculated 24-hour oxycodone dose in half to approximate the every 12-hour dose of OxyContin.
• Round down, if necessary, to the appropriate OxyContin tablet strengths available.
• Close observation and frequent titration are indicated until patients are stable on the new therapy.

2.3  Conversion from Transdermal Fentanyl to OxyContin

Eighteen hours following the removal of the transdermal fentanyl patch, OxyContin treatment can be initiated.  Although there has been no systematic assessment of such conversion, a conservative oxycodone dose, approximately 10 mg every 12 hours of OxyContin, should be initially substituted for each 25 mcg/hr fentanyl transdermal patch.  Follow the patient closely during conversion from transdermal fentanyl to OxyContin, as there is limited documented experience with this conversion.

2.4  Hepatic Impairment

For patients with hepatic impairment, start dosing patients at 1/3 to 1/2 the usual starting dose followed by careful dose titration [see Clinical Pharmacology (12.3)].

2.5  Managing Expected Opioid Adverse Reactions

Most patients receiving OxyContin, especially those who are opioid-naive, will experience adverse reactions. Patients do not usually become tolerant to the constipating effects of opioids, therefore, anticipate constipation  and treat aggressively and prophylactically with a stimulant laxative with or without a stool softener. If nausea persists and is unacceptable to the patient, consider treatment with antiemetics or other modalities to relieve these symptoms.

2.6  Individualization of Dosage

Once therapy is initiated, assess pain relief and other opioid effects frequently.  Titrate patients to adequate effect (generally mild or no pain with the regular use of no more than two doses of supplemental analgesia per 24 hours).  Patients who experience breakthrough pain may require dosage adjustment or rescue medication.  Because steady-state plasma concentrations are approximated within 24 to 36 hours, dosage adjustment may be carried out every 1 to 2 days. 

There are no well-controlled clinical studies evaluating the safety and efficacy with dosing more frequently than every 12 hours.  Increase the OxyContin dose by increasing the total daily dose, not by changing the 12-hour dosing interval. As a guideline, the total daily oxycodone dose usually can be increased by 25% to 50% of the current dose, each time an increase is clinically indicated.

If signs of excessive opioid-related adverse reactions are observed, the next dose may be reduced.  If this adjustment leads to inadequate analgesia, a supplemental dose of immediate-release oxycodone may be given.  Alternatively, non-opioid analgesic adjuvants may be employed.  Adjust the dose to obtain an appropriate balance between pain relief and opioid-related adverse reactions.

During periods of changing analgesic requirements, including initial titration, maintain frequent contact between physician, other members of the healthcare team, the patient and, with proper consent, the caregiver/family.

2.7  Special Instructions for Patients who are not Opioid Tolerant

Do not begin treatment with OxyContin 60 mg and 80 mg Tablets, a single dose greater than 40 mg, or a total daily dose greater than 80 mg in patients who are not already tolerant to the respiratory-depressant and sedating effects of opioids.  Use of these doses in patients who are not opioid tolerant may cause fatal respiratory depression.  These doses are only for use in opioid-tolerant patients. 

Patients considered opioid tolerant are those who are taking at least 60 mg oral morphine/day, 25 mcg transdermal fentanyl/hour, 30 mg oral oxycodone/day, 8 mg oral hydromorphone/day, 25 mg oral oxymorphone/day, or an equianalgesic dose of another opioid for one week or longer.

Instruct patients not to share or permit use by individuals other than the patient for whom OxyContin was prescribed, as such inappropriate use may have severe medical consequences, including death.

2.8  Continuation of Therapy

During chronic therapy, especially for non-cancer pain syndromes, reassess the continued need for around-the-clock opioid therapy regularly (e.g., every 6 to 12 months) as appropriate.

2.9  Cessation of Therapy

When the patient no longer requires therapy with OxyContin, taper the dose gradually to prevent signs and symptoms of withdrawal in the physically-dependent patient.

2.10  Conversion from OxyContin to Parenteral Opioids

To avoid overdose, follow conservative dose conversion ratios. When converting from OxyContin to parenteral opioids, it is advisable to calculate an equivalent parenteral dose and then initiate treatment at half of this calculated value.