INDICATIONS     CONTRA-INDICATIONS     DOSAGE     SIDE-EFFECTS     PREGNANCY     OVERDOSE     IDENTIFICATION     PATIENT INFORMATION
DUROGESIC®

SCHEDULING STATUS
Schedule 6.

PROPRIETARY NAME
(and dosage form)

DUROGESIC^®

DUROGESIC^®25 µg/h transdermal therapeutic system
DUROGESIC^®50 µg/h transdermal therapeutic system
DUROGESIC^®75 µg/h transdermal therapeutic system
DUROGESIC^®100 µg/h transdermal therapeutic system

COMPOSITION
Each 10 cm² transdermal therapeutic system contains 2,5 mg fentanyl, delivering 25 micrograms fentanyl/h.
Each 20 cm² transdermal therapeutic system contains 5 mg fentanyl, delivering 50 micrograms fentanyl/h.
Each 30 cm² transdermal therapeutic system contains 7,5 mg fentanyl, delivering 75 micrograms fentanyl/h.
Each 40 cm² transdermal therapeutic system contains 10 mg fentanyl, delivering 100 micrograms fentanyl/h.

PHARMACOLOGICAL CLASSIFICATION
A.2.9 Central Nervous System depressants. Other.

PHARMACOLOGICAL ACTION
Pharmacodynamics
Fentanyl is an opioid analgesic, interacting predominantly with the µ-opioid receptor. Its primary actions of therapeutic value are analgesia and sedation. Minimum effective analgesic serum concentrations of fentanyl in opioid naive patients range from 0,3 - 1,2 ng/mL; side-effects increase in frequency at serum levels above 2 ng/mL. Both the minimum concentration and the concentration at which opioid-related toxicity occurs, rise with increasing patient exposure to the drug. The rate of development of tolerance varies widely among individuals.
Pharmacokinetics
While there is variation in the dose delivered among patients, the normal flux of the individual system is sufficiently accurate to allow individual titration of dosage for a given patient. DUROGESIC provides nearly constant systemic delivery of fentanyl during the 72 hours application period. Fentanyl is released at a relatively constant rate, determined by the co-polymer release membrane and the diffusion of fentanyl through the skin. After initial DUROGESIC application, serum fentanyl concentrations increase gradually, generally levelling off between 12 and 24 hours and remaining relatively constant for the remainder of the 72 hours application period. Serum fentanyl concentrations attained are proportional to the DUROGESIC patch size. After repeated 72 hour applications, patients reach a steady state serum concentration that is maintained during subsequent applications of the patch of the same size.
After DUROGESIC removal, serum fentanyl concentrations decline gradually, falling about 50% in approximately 17 (range: 13-22) hours. Continued absorption of fentanyl from the skin accounts for a slower disappearance of the drug from the serum than is seen after an intravenous infusion.
Elderly, cachectic or debilitated patients may have reduced clearance of fentanyl and therefore the agent may have a greatly prolonged terminal half-life in such patients.
Fentanyl is metabolised primarily in the liver. Approximately 75% of fentanyl is excreted in urine mostly as metabolites with less than 10% representing unchanged drug. Approximately 9% of the dose is recovered in the faeces, primarily as metabolites. Mean value for unbound fraction of fentanyl in plasma is estimated to be between 13 and 21%.

INDICATIONS
DUROGESIC is indicated in the management of chronic intractable pain that requires opioid analgesia which cannot be managed by lesser means such as paracetamol-opioid combinations, non-steroidal analgesics or as required dosing with short acting opioids..

CONTRA-INDICATIONS
DUROGESIC is contra-indicated in pregnancy, lactation and children and patients with a known hypersensitivity to fentanyl or to the adhesives present in the transdermal therapeutic system.

WARNINGS
DUROGESIC SHOULD NOT BE USED IN THE MANAGEMENT OF ACUTE OR POSTOPERATIVE PAIN SINCE SERIOUS OR LIFE THREATENING HYPOVENTILATION COULD RESULT AND THERE IS NO OPPORTUNITY FOR DOSE TITRATION DURING SHORT TERM USE.
PATIENTS WHO HAVE EXPERIENCED OPIOID TOXICITY SHOULD BE MONITORED FOR AT LEAST 12 TO 24 HOURS AFTER DUROGESIC REMOVAL SINCE SERUM FENTANYL CONCENTRATIONS DECLINE GRADUALLY AND ARE REDUCED BY 50%, 17 (RANGE: 13-22) HOURS LATER.
DUROGESIC SHOULD BE PRESCRIBED ONLY BY PERSONS KNOWLEDGEABLE IN THE CONTINUOUS ADMINISTRATION OF POTENT OPIOIDS; IN THE MANAGEMENT OF PATIENTS RECEIVING POTENT OPIOIDS FOR TREATMENT OF PAIN AND IN THE DETECTION AND MANAGEMENT OF HYPOVENTILATION INCLUDING THE USE OF OPIOID ANTAGONISTS.

DOSAGE AND DIRECTIONS FOR USE
DUROGESIC doses should be individualised based upon the physical and opioid tolerance status of the patients and should be assessed at regular intervals after application.
DUROGESIC should be applied to non-irritated and non-irradiated skin on a flat surface of the torso or upper arms. Hair at the application site (a non-hairy area is preferable) should be clipped (not shaved) prior to application. If the site of DUROGESIC application must be cleansed prior to application of the system, this should be done with clear water. Soap, oils lotions or any other agent that might irritate the skin or alter its characteristics should not be used. The skin should be completely dry before the system is applied. DUROGESIC should be applied immediately upon removal from the sealed package. The transdermal therapeutic system should be pressed firmly in place with the palm of the hand for 30 seconds, making sure the contact is complete, especially around the edges.
DUROGESIC may be worn continuously for 72 hours. A new system should be applied on a different skin site after removal of the previous transdermal system. Several days should elapse before a new patch is applied to the same area of the skin.
Initial dose selection
There has been no systematic evaluation of DUROGESIC as an initial opioid analgesic in the management of chronic pain, since most patients in the clinical trials were converted to DUROGESIC from other narcotics.
Therefore, in opioid-naïve patients, the lowest DUROGESIC dose, 25 micrograms/h, should be used as the initial dose.
In opioid-tolerant patients, to convert from oral to parental opioids to DUROGESIC, the following procedure should be followed:

1	Calculate the previous 24 hour analgesic requirements.
2	Convert this amount to the equianalgesic oral morphine dose using Table 1. All intramuscular and oral doses in this chart are considered equivalent to 10 mg of intramuscular morphine in analgesic effect.
3	Table 2 displays the range of 24 hour oral morphine doses that are recommended for conversion to each DUROGESIC dose. Use this table to derive from the calculated 24 hour morphine dose the corresponding DUROGESIC dose.

TABLE 1: Equianalgesic potency conversion

DRUG NAME	EQUIANALGESIC DOSE (mg)
	Intramuscular*	Orally
Morphine	10	60 (30)**
Methadone	10	20
Pethidine	75	-
Codeine	130	200
Buprenorphine	0,4	0,8 (sublingual)

       

*	Based on single-dose studies in which an intramuscular dose of each drug listed was compared with morphine to establish the relative potency. Oral doses are those recommended when changing from parental to an oral route.
**	The oral/intramuscular potency ratio of 1: 3 for morphine is based on clinical experience in patients with chronic pain.

TABLE 2: Recommended DUROGESIC dose based upon daily oral morphine dose*

Oral 24 hour morphine (mg/day)	DUROGESIC dose (micrograms/h)
< 135	25
135-224	50
225-314	75
315-404	100
405-494	125
495-584	150
585-674	175
675-764	200
765-854	225
855-944	250
945-1034	275
1035-1124	300

*	In clinical trials these ranges of daily oral morphine doses were used as a basis for conversion to DUROGESIC.

Both in opioid-naive and opioid-tolerant patients, the initial evaluation of the maximum analgesic effect of DUROGESIC, cannot be made before the system is worn for 24 hours. This delay is due to the gradual increase in serum fentanyl concentration in the 24 hours following initial system application. Previous analgesic therapy should be gradually phased out after the initial dose application until analgesic efficacy with DUROGESIC is attained.
Dose titration and maintenance therapy
The conversion ratio from oral morphine to DUROGESIC is conservative and 50% of patients are likely to require a dose increase after the initial application.
The DUROGESIC patch should be replaced every 72 hours. The dose should be titrated individually until analgesic efficacy is attained. If analgesia is insufficient after the initial application, the dose may be increased after 3 days, based on the daily dose of supplementary analgesics required by the patient in the second or third day of initial application. Thereafter, dose adjustment can take place every 3 days.
Physicians are advised that it may take up to 6 days after increasing the dose of DUROGESIC for the patient to reach equilibrium on the new dose. Therefore patients should wear a higher dose through two applications before any further increase in dosage is made, on the basis of the average daily use of a supplemental analgesic.
Dosage titration should normally be performed in 25 micrograms/h increments, although the supplementary analgesic requirements (oral morphine 90 mg/day ~ 25 micrograms/h) and pain status of the patient should be taken into account. More than one DUROGESIC system may be used for doses greater than 100 micrograms/h. Patients may require periodic supplementary doses of a short acting analgesic for "breakthrough" pain. Some patients may require additional or alternative methods of opioid administration when the DUROGESIC dose exceed 300 micrograms/h.
Discontinuation of DUROGESIC
If discontinuation of DUROGESIC is necessary, replacement with other opioids should be gradual, starting at low dose and increasing slowly. This is because fentanyl levels fall gradually after DUROGESIC is removed. It takes 17 hours or more for the fentanyl serum concentrations to decrease 50%. In general, the discontinuation of opioids analgesia should be gradual in order to prevent withdrawal symptoms.
Disposal of the patch
Used systems should be folded so that the adhesive side of the system adheres to itself, and flushed down the toilet immediately upon removal. Patients should be advised to safely dispose of any system remaining from a prescription as soon as they are no longer needed. Unused systems should be removed from their pouch and flushed down the toilet.

SIDE-EFFECTS AND SPECIAL PRECAUTIONS
The most serious side-effect, which can occur throughout the therapeutic range of fentanyl serum concentration is hypoventilation. Other opioid related side-effects reported include: nausea, vomiting, dry mouth, constipation, hypotension and hypertension, bradycardia, somnolence, confusion, hallucinations, euphoria, pruritus, sweating and urinary retention.
Skin reactions such as rash, erythema, oedema, papules and itching have occasionally been reported. These reactions resolve after removal of the patch.
The following adverse reaction were reported: abdominal pain, abdominal distention, headache, arrhythmia, chest pain, anorexia, diarrhoea, dyspepsia, flatulence, aphasia, asthenia, dizziness, nervousness, anxiety, depression, tremor, abnormal co-ordination, abnormal thinking, abnormal gait, abnormal dreams, agitation, paraesthesia, amnesia, syncope, paranoid reaction, dyspnoea, apnoea, haemoptysis, pharyngitis, hiccups, sweating, hypertonia, vertigo, stupor, hypotonia, depersonalisation, hostility, stertorous breathing, asthma, respiratory disorder, exfoliative dermatitis, pustules, amblyopia, bladder pain, oliguria, urinary frequency.
Opioid withdrawal symptoms (such as nausea, vomiting, diarrhoea, anxiety and shivering) are possible in some patients after conversion from their previous opioid analgesic to DUROGESIC.
Precautions
DUROGESIC should be kept out of reach of children before and after use.
DUROGESIC patches should not be divided, cut or damaged in any other way since this leads to uncontrolled release of fentanyl.
Some patients may experience significant respiratory depression with DUROGESIC; patients must be observed for these effects. Respiratory depression may persist beyond the removal of the DUROGESIC system. The incidence of respiratory depression increases as the DUROGESIC dose is increased. Central nervous system active agents may increase the respiratory depression.
DUROGESIC may have more severe adverse effects in patients with chronic obstructive pulmonary disease, or other pulmonary disease. In such patients, opioids may decrease respiratory drive and increase airway resistance.
Tolerance and physical and psychological dependence may develop upon repeated administration of opioids.
DUROGESIC should not be used in patients who may be particularly susceptible to the intracranial effects of CO² retention such as those with evidence of increased intracranial pressure, impaired consciousness, or coma. DUROGESIC should be used with caution in patients with brain tumours. Opioids may obscure the clinical course of patients with head injury.
DUROGESIC may produce bradycardia and should therefore be administered with caution to patients with bradyarrhythmias.
Presently insufficient information exists to make recommendations regarding the use of DUROGESIC in patients with impaired renal or hepatic functions. If the drug is used in these patients, it should be used with caution because of the hepatic metabolism and limited renal excretion of fentanyl.
A pharmacokinetic model suggests that serum fentanyl concentrations may increase by about one third if the skin temperature increases to 40°C. Therefore, patients with fever should be monitored for opioid side-effects and the DUROGESIC dose should be adjusted if necessary.
All patients should be advised to avoid exposing the DUROGESIC application site to direct external heat sources such as heating pads, electric blankets, heated water beds, heat lamps, intensive sunbathing, hot water bottles, saunas and hot whirlpool spa baths.
Data from intravenous studies with fentanyl suggest that elderly patients may have reduced clearance, a prolonged half-life and they may be more sensitive to the drug than younger patients. In studies of DUROGESIC, elderly patients had fentanyl pharmacokinetics which did not differ significantly from young patients although serum concentrations tended to be higher. Elderly patients should be observed carefully for signs of fentanyl toxicity and the dose reduced if necessary.
The safe use of fentanyl has not been established with respect to possible adverse effects upon foetal development. Therefore, DUROGESIC should not be used in women of childbearing potential unless, in the judgement of the physician, the potential benefits outweighs the possible hazards. Fentanyl is excreted in human milk, therefore DUROGESIC is not recommended for use in nursing women.
Interactions
The concomitant use of other central nervous system depressants, including other opioids, sedatives, hypnotics, general anaesthetics, phenothiazines, tranquillizers, skeletal muscle relaxants, sedating antihistamines and alcoholic beverages may produce significant additive depressant effects; hypoventilation, hypotension and profound sedation or coma may occur. Therefore, the use of any of these drugs concomitantly with DUROGESIC requires special patient care and observation. The initial dose of other central nervous system depressants should be reduced by 50%.
Fentanyl, a high clearance drug, is rapidly and extensively metabolised mainly by CYP3A4. Itraconazole (a potent CYP3A4 inhibitor) at 200 mg/day given orally for 4 days had no significant effect on the pharmacokinetics of IV fentanyl. Oral ritonavir (one of the most potent CYP3A4 inhibitors) reduced the clearance of IV fentanyl by two-thirds.
Although clinical data are lacking, in-vitro data suggest that other potent cytochrome P450 3A4 enzyme inhibitors (e.g. fluconazole, ketoconazole, erythromycin, diltiazem and cimetidine) may inhibit the metabolism of fentanyl.
The concomitant use of potent CYP3A4 inhibitors such as ritonavir with transdermal fentanyl may result in an increase in fentanyl plasma concentrations, which could increase or prolong both the therapeutic and adverse effects, and may cause serious respiratory depression. In this situation, special patient care and observation are appropriate. The concomitant use of ritonavir and transdermal fentanyl is not recommended, unless the patient is closely monitored.
DUROGESIC should be used with caution in patients who have a history of drug or alcohol abuse, especially if they are outside a medically controlled environment.
DUROGESIC may impair the mental and/or physical ability required for the performance of potentially hazardous tasks such as driving a car or operating machinery.

KNOWN SYMPTOMS OF OVERDOSAGE AND PARTICULARS OF ITS TREATMENT
Symptoms
The manifestations of fentanyl overdosage are an extension of its pharmacological action, the most serious effect being respiratory depression.
Treatment
For the management of respiratory depression, immediate countermeasures include removing the DUROGESIC patch and physically or verbally stimulating the patients. These actions can be followed by administration of the specific narcotic antagonist, naloxone. Respiratory depression following an overdose may outlast the duration of action of the opioid antagonist. The interval between intravenous antagonist doses should be carefully chosen because of the possibility of re-narcotization after system removal; repeated administration of naloxone may be necessary. Reversal of the narcotic effect may result in acute onset of pain and release of catecholamines.
If the clinical situation warrants, a patent airway should be established and maintained, possibly with an oropharyngeal airway or endotracheal tube and oxygen should be administered and respiration assisted or controlled, as appropriate. Adequate body temperature and fluid intake should be maintained. If severe or persistent hypotension occurs, the possibility of hypovolemia should be considered and the condition should be managed with appropriate parenteral fluid therapy.

IDENTIFICATION
DUROGESIC patches are rectangular with round corners, translucent units comprising a protective liner and four functional layers.
DUROGESIC patches are available in 4 strengths:
-        DUROGESIC 100 micrograms/h: grey coloured printing
-        DUROGESIC 75 micrograms/h: blue coloured printing
-        DUROGESIC 50 micrograms/h: green coloured printing
-        DUROGESIC 25 micrograms/h: pink coloured printing

PRESENTATION
DUROGESIC is packed in cartons containing 5 individually packaged systems.

STORAGE DIRECTIONS
Store below 25°C.
KEEP OUT OF REACH OF CHILDREN BEFORE AND AFTER USE.

REGISTRATION NUMBERS

25 micrograms/h - 28/2.9/0288	50 micrograms/h - 28/2.9/0289
75 micrograms/h - 28/2.9/0290	100 micrograms/h - 28/2.9/0291

NAME AND BUSINESS ADDRESS OF THE APPLICANT
JANSSEN - CILAG logo
JANSSEN PHARMACEUTICA (PTY) LTD
(Reg. No. 1980/011122/07)
15th Road
HALFWAY HOUSE, 1685
www.janssencilag.co.za

DATE OF PUBLICATION OF THIS PACKAGE INSERT
19 May 1999

        Code No: 024398
        2003H
        Britepak

Updated on this site: May 2004
Source: Pharmaceutical Industry
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