Opana ER Dosage

2.1   Safe Administration Instructions

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

Patients must not consume alcoholic beverages, or prescription or non-prescription medications containing alcohol, while on OPANA ER therapy.  The co-ingestion of alcohol with OPANA ER may result in increased plasma levels and a potentially fatal overdose of oxymorphone.

OPANA ER tablets must be taken whole, one tablet at a time, with enough water to ensure complete swallowing immediately after placing in the mouth [see Patient Counseling Information (17)].

OPANA ER must be taken on an empty stomach, at least one hour prior to or two hours after eating [see Clinical Pharmacology (12.3)].

While symmetric (same dose AM and PM), around-the-clock, every 12 hours dosing is appropriate for the majority of patients, some patients may benefit from asymmetric (different dose given in AM than in PM) dosing, tailored to their pain pattern.  It is usually appropriate to treat a patient with only one extended-release opioid for around-the-clock therapy.

Selection of patients for treatment with OPANA ER should be governed by the same principles that apply to the use of other extended-release opioid analgesics [see Indications and Usage (1)].  Physicians should individualize treatment in every case, using non-opioid analgesics, opioids on an as needed basis, combination products, and chronic opioid therapy in a progressiveplan of pain management such as outlined by the World Health Organization, the American Pain Society and the Federation of State Medical Boards Model Guidelines.  Healthcare professionals should follow appropriate pain management principles of careful assessment and ongoing monitoring [see Boxed Warning].

2.2  Initiating Therapy with OPANA ER

It is necessary to adjust the dosing regimen for each patient individually, taking into account the patient’s prior analgesic treatment experience. In the selection of the initial dose of OPANA ER, attention should be given to the following:

• total daily dose, potency and specific characteristics of the opioid the patient has been taking previously;
• relative potency estimate used to calculate the equivalent oxymorphone dose needed;
• patient’s degree of opioid tolerance;
• age, general condition, and medical status of the patient;
• concurrent non-opioid analgesics and other medications;
• type and severity of the patient’s pain;
• balance between pain control and adverse experiences;
• risk factors for abuse or addiction, including a prior history of abuse or addiction.

Once therapy is initiated, frequently assess pain relief and other opioid effects. Base the titration of the total daily OPANA ER dose upon the amount of supplemental opioid utilization, severity of the patient’s pain, and the patient’s ability to tolerate the opioid.  Titrate dose to generally mild or no pain with the regular use of no more than two doses of supplemental analgesia, i.e. “rescue,” per 24 hours, and tolerable side effects. Patients who experience breakthrough pain may require dosage adjustment.

If signs of excessive opioid-related adverse experiences are observed, the next dose may be reduced.  If this adjustment leads to inadequate analgesia, a supplemental dose of immediate-release opioid,  or a non-opioid analgesic may be administered. Adjust dosing to obtain an appropriate balance between pain relief and opioid-related adverse experiences.  If significant adverse events occur before the therapeutic goal of mild or no pain is achieved, the events should be treated aggressively.  If adverse events are adequately managed, continue upward titration to an acceptable level of pain control.

During periods of changing analgesic requirements, including initial titration, frequent contact is recommended between physician, other members of the healthcare team, the patient and the caregiver/family. Advise patients and caregivers/family members of the potential adverse reactions.

The dosing recommendations below, therefore, can only be considered as suggested approaches to what is actually a series of clinical decisions over time in the management of the pain of each individual patient.

Titrate dose to adequate pain relief (generally mild or no pain).

Opioid-Naïve Patients
The initial dose for patients who are not opioid-experienced and who are being initiated on chronic around-the-clock opioid therapy with OPANA ER is 5 mg every 12 hours.  Thereafter, titrate the dose individually at increments of 5-10 mg every 12 hours every 3-7 days, to a level that provides adequate analgesia and tolerable side effects under the close supervision of the prescribing physician.

Opioid-Experienced Patients
Conversion from OPANA to OPANA ER
Patients receiving OPANA may be converted to OPANA ER by administering half the patient's total daily oral OPANA dose as OPANA ER, every 12 hours. 

Conversion from Parenteral Oxymorphone to OPANA ER
Given OPANA ER’s absolute oral bioavailability of approximately 10%, patients receiving parenteral oxymorphone may be converted to OPANA ER by administering 10 times the patient's total daily parenteral oxymorphone dose as OPANA ER in two equally divided doses (e.g., [IV dose x 10] divided by 2). Due to patient variability with regards to opioid analgesic response, upon conversion monitor patients closely to evaluate for adequate analgesia and side effects.

Conversion from Other Oral Opioids to OPANA ER
For conversion from other opioids to OPANA ER, physicians and other healthcare professionals are advised to refer to published relative potency information, keeping in mind that conversion ratios are only approximate. 

The following table provides approximate equivalent doses, which may be used as a guideline for conversion.  The conversion ratios and approximate equivalent doses in this conversion table are only to be used for the conversion from current opioid therapy to OPANA ER.  

• In general, it is safest to start the OPANA ER therapy by administering 50% of the calculated total daily dose, calculated below, of OPANA ER (see conversion ratio table below) in 2 divided doses, every 12 hours. Gradually adjust the initial dose of OPANA ER until adequate pain relief and acceptable side effects have been achieved.

        Calculating the total daily dose of OPANA ER:

        Step 1    Calculate the total daily dose of the opioid.

        Step 2    Multiply the total daily dose for the opioid by the conversation ratio in Table 1 to calculate the total daily oxymorphone dose. 

Table 1:  Oral Opioid Conversion Ratios to OPANA ER

Step 3    Adjust the total daily dose of oxymorphone for the individual patient.

Step 4    Divide the total daily oxymorphone dose in half to determine the OPANA ER dose to be administered every 12 hours.

• For patients on a regimen of mixed opioids, calculate the approximate oral oxymorphone dose for each opioid, sum the totals, and divide in half to estimate the total daily oxymorphone dose.
• The dose of OPANA ER can be gradually adjusted, preferably at increments of 10 mg every 12 hours every 3-7 days, until adequate pain relief and acceptable side effects have been achieved [see Dosage and Administration (2.1)].

aIt is extremely important to monitor all patients closely when converting from methadone to other opioid agonists including OPANA ER. The ratio between methadone and other opioid agonists may vary widely as a function of previous dose exposure. Methadone has a long half-life and accumulates in the plasma.

No dose adjustment for CYP 3A4 or 2C9 mediated drug-drug interactions is required [see Clinical Pharmacology (12.3)].

2.3   Patients with Hepatic Impairment

Start patients with mild hepatic impairment with the lowest dose and titrated slowly while carefully monitoring side effects. OPANA ER is contraindicated in patients with moderate or severe hepatic impairment [see Warnings and Precautions (5.7) and Clinical Pharmacology (12.3)].

2.4   Patients with Renal Impairment

There are 57% and 65% increases in oxymorphone bioavailability in patients with moderate and severe renal impairment, respectively [see Clinical Pharmacology (12.3)].  Accordingly, in patients with creatinine clearance rates less than 50 mL/min, start OPANA ER with the lowest dose and titrate slowly while carefully monitoring side effects.

2.5   Use with Central Nervous System Depressants

In patients who are concurrently receiving other central nervous system (CNS) depressants including sedatives or hypnotics, general anesthetics, phenothiazines, tranquilizers, and alcohol, start OPANA ER at 1/3 to 1/2 of the usual dose because respiratory depression, hypotension, and profound sedation, coma or death may result [see Warnings and Precautions (5.4) and Drug Interactions (7.2)]. 

Although no specific interaction between oxymorphone and monoamine oxidase inhibitors has been observed, OPANA ER is not recommended for use in patients who have received MAO inhibitors within 14 days [see Drug Interactions (7.6)].

2.6   Geriatric Patients

The steady-state plasma concentrations of oxymorphone are approximately 40% higher in elderly subjects than in young subjects.  Exercise caution in the selection of the starting dose of OPANA ER for an elderly patient by starting at the low end of the dosing range and slowly titrating to adequate analgesia [see Clinical Pharmacology (12.3) and Use in Specific Populations (8.5)].

2.7   Maintenance of Therapy

During chronic therapy with OPANA ER, periodically reassess the continued need for around-the-clock opioid therapy.  Continue to assess patients for their clinical risks for opioid abuse, addiction, or diversion particularly with high-dose formulations.  If patients need to titrate while on maintenance therapy, follow the same method outlined in Initiating Therapy with OPANA ER .

2.8  Cessation of Therapy

When the patient no longer requires therapy with OPANA ER tablets, gradually taper doses to prevent signs and symptoms of withdrawal in the physically dependent patient.