Palexia sr

Palexia sr Medicine

Overdose

Symptoms

Human experience with overdose of tapentadol is very limited. Preclinical data suggest that symptoms similar to those of other centrally acting analgesics with mu-opioid receptor agonist activity are to be expected upon intoxication with tapentadol. In principle, these symptoms include, referring to the clinical setting, in particular miosis, vomiting, cardiovascular collapse, consciousness disorders up to coma, convulsions and respiratory depression up to respiratory arrest.

Management

Management of overdose should be focused on treating symptoms of mu-opioid agonism. Primary attention should be given to re-establishment of a patent airway and institution of assisted or controlled ventilation when overdose of tapentadol is suspected.

Pure opioid receptor antagonists such as naloxone are specific antidotes to respiratory depression resulting from opioid overdose. Respiratory depression following an overdose may outlast the duration of action of the opioid receptor antagonist. Administration of an opioid receptor antagonist is not a substitute for continuous monitoring of airway, breathing, and circulation following an opioid overdose. If the response to opioid receptor antagonists is suboptimal or only brief in nature, an additional dose of antagonist (e.g. naloxone) should be administered as directed by the manufacturer of the product.

Gastrointestinal decontamination may be considered in order to eliminate unabsorbed active substance. Gastrointestinal decontamination with activated charcoal or by gastric lavage may be considered within 2 hours after intake. Before attempting gastrointestinal decontamination, care should be taken to secure the airway.

Shelf life

3 years

Contraindications

PALEXIA SR is contraindicated

- in patients with hypersensitivity to tapentadol or to any of the excipients listed in section 6.1.

- in situations where active substances with mu-opioid receptor agonist activity are contraindicated, i.e. patients with significant respiratory depression (in unmonitored settings or the absence of resuscitative equipment), and patients with acute or severe bronchial asthma or hypercapnia

- in any patient who has or is suspected of having paralytic ileus

- in patients with acute intoxication with alcohol, hypnotics, centrally acting analgesics, or psychotropic active substances

Incompatibilities

Not applicable

List of excipients

Tablet core (all doses):

Hypromellose

Microcrystalline cellulose

Colloidal anhydrous silica

Magnesium stearate

Tablet coat:

Hypromellose

Lactose monohydrate

Talc

Macrogol 6000

Propylene glycol

Titanium dioxide (E 171) - 50mg, 100mg, 150mg

Yellow iron oxide (E 172) - 100mg, 150mg

Red iron oxide (E 172) - 150mg, 200mg

Black iron oxide (E 172) - 250mg

Pharmaceutical form

Prolonged-release tablet

50 mg: White film-coated oblong shaped tablets (6.5 mm x 15 mm) marked with Grünenthal logo on one side and “H1” on the other side.

100 mg: Pale yellow film-coated oblong shaped tablets (6.5 mm x 15 mm) marked with Grünenthal logo on one side and “H2” on the other side.

150 mg: Pale pink film-coated oblong shaped tablets (6.5 mm x 15 mm) marked with Grünenthal logo on one side and “H3” on the other side.

200 mg: Pale orange film-coated oblong shaped tablets (7 mm x 17 mm) marked with Grünenthal logo on one side and “H4” on the other side.

250 mg: Brownish red film-coated oblong shaped tablets (7 mm x 17 mm) marked with Grünenthal logo on one side and “H5” on the other side.

Undesirable effects

The adverse drug reactions that were experienced by patients in the placebo controlled trials performed with PALEXIA SR were predominantly of mild and moderate severity. The most frequent adverse drug reactions were in the gastrointestinal and central nervous system (nausea, dizziness, constipation, headache and somnolence).

The table below lists adverse drug reactions that were identified from clinical trials performed with PALEXIA SR and from post-marketing environment. They are listed by class and frequency. Frequencies are defined as very common (>1/10); common (>1/100 to <1/10); uncommon (>1/1,000 to <1/100); rare (>1/10,000 to <1/1,000); very rare (<1/10,000), not known (cannot be estimated from the available data).

ADVERSE DRUG REACTIONS

System Organ Class

Frequency

Very common

Common

Uncommon

Rare

Immune system disorders

Drug hypersensitivity*

Metabolism and nutrition disorders

Decreased appetite

Weight decreased

Psychiatric disorders

Anxiety, Depressed mood, Sleep disorder, Nervousness, Restlessness

Disorientation, Confusional state, Agitation, Perception disturbances, Abnormal dreams, Euphoric mood

Drug dependence, Thinking abnormal

Nervous system disorders

Dizziness, Somnolence, Headache

Disturbance in attention, Tremor, Muscle contractions involuntary

Depressed level of consciousness, Memory impairment, Mental impairment, Syncope, Sedation, Balance disorder, Dysarthria, Hypoaesthesia, Paraesthesia

Convulsion, Presyncope, Coordination abnormal

Eye disorders

Visual disturbance

Cardiac disorders

Heart rate increased, Heart rate decreased, Palpitations

Vascular disorders

Flushing

Blood pressure decreased

Respiratory, thoracic and mediastinal disorders

Dyspnoea

Respiratory depression

Gastrointestinal disorders

Nausea, Constipation

Vomiting, Diarrhoea, Dyspepsia

Abdominal discomfort

Impaired gastric emptying

Skin and subcutaneous tissue disorders

Pruritus, Hyperhidrosis, Rash

Urticaria

Renal and urinary disorders

Urinary hesitation, Pollakiuria

Reproductive system and breast disorders

Sexual dysfunction

General disorders and administration site conditions

Asthenia, Fatigue, Feeling of body temperature change, Mucosal dryness, Oedema

Drug withdrawal syndrome, Feeling abnormal, Irritability

Feeling drunk, Feeling of relaxation

* Post-marketing rare events of angioedema, anaphylaxis and anaphylactic shock have been reported.

Clinical trials performed with PALEXIA SR with patient exposure up to 1 year have shown little evidence of withdrawal symptoms upon abrupt discontinuations and these were generally classified as mild, when they occurred. Nevertheless, physicians should be vigilant for symptoms of withdrawal and treat patients accordingly should they occur.

The risk of suicidal ideation and suicides committed is known to be higher in patients suffering from chronic pain. In addition, substances with a pronounced influence on the monoaminergic system have been associated with an increased risk of suicidality in patients suffering from depression, especially at the beginning of treatment. For tapentadol data from clinical trials and post-marketing reports do not provide evidence for an increased risk.

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme at: www.mhra.gov.uk/yellowcard.

Preclinical safety data

Tapentadol was not genotoxic in bacteria in the Ames test. Equivocal findings were observed in an in vitro chromosomal aberration test, but when the test was repeated the results were clearly negative. Tapentadol was not genotoxic in vivo, using the two endpoints of chromosomal aberration and unscheduled DNA synthesis, when tested up to the maximum tolerated dose. Long-term animal studies did not identify a potential carcinogenic risk relevant to humans.

Tapentadol had no influence on male or female fertility in rats but there was reduced in utero survival at the high dose. It is not known whether this was mediated via the male or the female. Tapentadol showed no teratogenic effects in rats and rabbits following intravenous and subcutaneous exposure. However, delayed development and embryotoxicity were observed after administration of doses resulting in exaggerated pharmacology (mu-opioid related CNS effects related to dosing above the therapeutic range). After intravenous dosing in rats reduced in utero survival was seen. In rats tapentadol caused increased mortality of the F1 pups that were directly exposed via milk between days 1 and 4 postpartum already at dosages that did not provoke maternal toxicities. There were no effects on neurobehavioral parameters.

Excretion into breast milk was investigated in rat pups suckled by dams dosed with tapentadol. Pups were dose-dependently exposed to tapentadol and tapentadol O-glucuronide. It was concluded that tapentadol is excreted in milk.

Therapeutic indications

PALEXIA SR is indicated for the management of severe chronic pain in adults, which can be adequately managed only with opioid analgesics.

Pharmacotherapeutic group

Analgesics; opioids; other opioids

Pharmacodynamic properties

Pharmacotherapeutic group: Analgesics; opioids; other opioids

ATC code: N02AX06

Tapentadol is a strong analgesic with µ-agonistic opioid and additional noradrenaline reuptake inhibition properties. Tapentadol exerts its analgesic effects directly without a pharmacologically active metabolite.

Tapentadol demonstrated efficacy in preclinical models of nociceptive, neuropathic, visceral and inflammatory pain; efficacy has been verified in clinical trials with tapentadol prolonged-release tablets in non-malignant nociceptive and neuropathic chronic pain conditions as well as chronic tumour-related pain. The trials in pain due to osteoarthritis and chronic low back pain showed similar analgesic efficacy of tapentadol to a strong opioid used as a comparator. In the trial in painful diabetic peripheral neuropathy tapentadol separated from placebo which was used as comparator.

Effects on the cardiovascular system: In a thorough human QT trial, no effect of multiple therapeutic and supratherapeutic doses of tapentadol on the QT interval was shown. Similarly, tapentadol had no relevant effect on other ECG parameters (heart rate, PR interval, QRS duration, T-wave or U-wave morphology).

Paediatric population

).

Post-marketing data

Two post-marketing studies were performed to address the practical use of tapentadol.

The efficacy of tapentadol prolonged-release tablets has been verified in a multicenter, randomized, double blind parallel-group trial with patients suffering from low back pain with a neuropathic component (KF5503/58). Reductions in average pain intensity were similar in the tapentadol treatment group and the comparator treatment group i.e. receiving a combination of tapentadol prolonged-release tablets and pregabalin immediate release tablets.

In an open-label, multicenter, randomized trial with patients having severe chronic low back pain with a neuropathic component (KF5503/60), tapentadol prolonged-release tablets were associated with significant reductions in average pain intensity.

Pharmacokinetic properties

Absorption

Mean absolute bioavailability after single-dose administration (fasting) of Palexia SR is approximately 32% due to extensive first-pass metabolism. Maximum serum concentrations of tapentadol are observed at between 3 and 6 hours after administration of prolonged-release tablets.

Dose proportional increases for AUC have been observed after administration of the prolonged-release tablets over the therapeutic dose range.

A multiple dose trial with twice daily dosing using 86 mg and 172 mg tapentadol administered as prolonged-release tablets showed an accumulation ratio of about 1.5 for the parent active substance which is primarily determined by the dosing interval and apparent half-life of tapentadol. Steady state serum concentrations of tapentadol are reached on the second day of the treatment regimen.

Food Effect

The AUC and Cmax increased by 8% and 18%, respectively, when prolonged-release tablets were administered after a high-fat, high-calorie breakfast. This was judged to be without clinical relevance as it falls into the normal inter-subject variability of tapentadol PK parameters. PALEXIA SR may be given with or without food.

Distribution

Tapentadol is widely distributed throughout the body. Following intravenous administration, the volume of distribution (Vz) for tapentadol is 540 +/- 98 l. The serum protein binding is low and amounts to approximately 20%.

Metabolism

In humans, the metabolism of tapentadol is extensive. About 97% of the parent compound is metabolised. The major pathway of tapentadol metabolism is conjugation with glucuronic acid to produce glucuronides. After oral administration approximately 70% of the dose is excreted in urine as conjugated forms (55% glucuronide and 15% sulfate of tapentadol). Uridine diphosphate glucuronyl transferase (UGT) is the primary enzyme involved in the glucuronidation (mainly UGT1A6, UGT1A9 and UGT2B7 isoforms). A total of 3% of active substance is excreted in urine as unchanged active substance. Tapentadol is additionally metabolised to N-desmethyl tapentadol (13%) by CYP2C9 and CYP2C19 and to hydroxy tapentadol (2%) by CYP2D6, which are further metabolised by conjugation. Therefore, active substance metabolism mediated by cytochrome P450 system is of less importance than glucuronidation.

None of the metabolites contributes to the analgesic activity.

Elimination

Tapentadol and its metabolites are excreted almost exclusively (99%) via the kidneys. The total clearance after intravenous administration is 1530 +/- 177 ml/min. Terminal half-life is on average 5-6 hours after oral administration.

Special populations

Elderly patients

The mean exposure (AUC) to tapentadol was similar in a trial with elderly subjects (65-78 years of age) compared to young adults (19-43 years of age), with a 16% lower mean Cmax observed in the elderly subject group compared to young adult subjects.

Renal Impairment

AUC and Cmax of tapentadol were comparable in subjects with varying degrees of renal function (from normal to severely impaired). In contrast, increasing exposure (AUC) to tapentadol-O-glucuronide was observed with increasing degree of renal impairment. In subjects with mild, moderate, and severe renal impairment, the AUC of tapentadol-O-glucuronide are 1.5-, 2.5-, and 5.5-fold higher compared with normal renal function, respectively.

Hepatic Impairment

Administration of tapentadol resulted in higher exposures and serum levels to tapentadol in subjects with impaired hepatic function compared to subjects with normal hepatic function. The ratio of tapentadol pharmacokinetic parameters for the mild and moderate hepatic impairment groups in comparison to the normal hepatic function group were 1.7 and 4.2, respectively, for AUC; 1.4 and 2.5, respectively, for Cmax; and 1.2 and 1.4, respectively, for t1/2. The rate of formation of tapentadol-O-glucuronide was lower in subjects with increased liver impairment.

Pharmacokinetic Interactions

Tapentadol is mainly metabolised by glucuronidation, and only a small amount is metabolised by oxidative pathways.

As glucuronidation is a high capacity/low affinity system, which is not easily saturated even in disease, and as therapeutic concentrations of active substances are generally well below the concentrations needed for potential inhibition of glucuronidation, any clinically relevant interactions caused by glucoronidation are unlikely to occur. In a set of drug-drug interaction trials using paracetamol, naproxen, acetylsalicylic acid and probenecid, a possible influence of these active substances on the glucuronidation of tapentadol was investigated. The trials with probe active substances naproxen (500 mg twice daily for 2 days) and probenecid (500 mg twice daily for 2 days) showed increases in AUC of tapentadol by 17% and 57%, respectively. Overall, no clinically relevant effects on the serum concentrations of tapentadol were observed in these trials.

Furthermore, interaction trials of tapentadol with metoclopramide and omeprazole were conducted to investigate a possible influence of these active substances on the absorption of tapentadol. These trials also showed no clinically relevant effects on tapentadol serum concentrations.

In vitro studies did not reveal any potential of tapentadol to either inhibit or induce cytochrome P450 enzymes. Thus, clinically relevant interactions mediated by the cytochrome P450 system are unlikely to occur.

Plasma protein binding of tapentadol is low (approximately 20%). Therefore, the likelihood of pharmacokinetic drug-drug interactions by displacement from the protein binding site is low.

Date of revision of the text

06 December 2017

Name of the medicinal product

PALEXIA® SR 50 mg prolonged-release tablets

PALEXIA® SR 100 mg prolonged-release tablets

PALEXIA® SR 150 mg prolonged-release tablets

PALEXIA® SR 200 mg prolonged-release tablets

PALEXIA® SR 250 mg prolonged-release tablets

Marketing authorisation holder

Grünenthal Ltd

Regus Lakeside House

1 Furzeground Way

Stockley Park East

Uxbridge

Middlesex UB11 1BD

United Kingdom

Special precautions for storage

This medicinal product does not require any special storage conditions.

Nature and contents of container

PVC/PVDC-aluminium/paper/PET blisters

Packs with 7, 10, 14, 20, 24, 28, 30, 40, 50, 54, 56, 60, 90, 100 prolonged-release tablets.

PVC/PVDC aluminium/paper/PET perforated unit-dose blisters

Packs with 10, 14, 20, 28, 30, 50, 56, 60, 90, 100 prolonged-release tablets.

Not all pack sizes may be marketed.

Marketing authorisation number(s)

PALEXIA® SR 50 mg prolonged-release tablets: PL 21727/0041

PALEXIA® SR 100 mg prolonged-release tablets: PL 21727/0042

PALEXIA® SR 150 mg prolonged-release tablets: PL 21727/0043

PALEXIA® SR 200 mg prolonged-release tablets: PL 21727/0044

PALEXIA® SR 250 mg prolonged-release tablets: PL 21727/0045

Fertility, pregnancy and lactation

Pregnancy

There is very limited amount of data from the use in pregnant women.

Studies in animals have not shown teratogenic effects. However, delayed development and embryotoxicity were observed at doses resulting in exaggerated pharmacology (mu-opioid-related CNS effects related to dosing above the therapeutic range). Effects on the postnatal development were already observed at the maternal NOAEL.

PALEXIA SR should be used during pregnancy only if the potential benefit justifies the potential risk to the foetus.

Labour and Delivery

The effect of tapentadol on labour and delivery in humans is unknown. PALEXIA SR is not recommended for use in women during and immediately before labour and delivery. Due to the mu-opioid receptor agonist activity of tapentadol, new-born infants whose mothers have been taking tapentadol should be monitored for respiratory depression.

Lactation

There is no information on the excretion of tapentadol in human milk. From a study in rat pups suckled by dams dosed with tapentadol it was concluded that tapentadol is excreted via milk. Therefore, a risk to the suckling child cannot be excluded. PALEXIA SR should not be used during breast feeding.

Qualitative and quantitative composition

Each prolonged-release tablet contains 50 mg tapentadol (as hydrochloride).

Each prolonged-release tablet contains 100 mg tapentadol (as hydrochloride).

Each prolonged-release tablet contains 150 mg tapentadol (as hydrochloride).

Each prolonged-release tablet contains 200 mg tapentadol (as hydrochloride).

Each prolonged-release tablet contains 250 mg tapentadol (as hydrochloride).

Excipient(s) with known effect:

PALEXIA SR 50 mg contains 3.026 mg lactose.

PALEXIA SR 100 mg contains 3.026 mg lactose.

PALEXIA SR 150 mg contains 3.026 mg lactose.

PALEXIA SR 200 mg contains 3.026 mg lactose.

PALEXIA SR 250 mg contains 3.026 mg lactose.

Special warnings and precautions for use

Potential for Abuse and Addiction/ Dependence Syndrome

PALEXIA SR has a potential for abuse and addiction. This should be considered when prescribing or dispensing PALEXIA SR in situations where there is concern about an increased risk of misuse, abuse, addiction, or diversion.

All patients treated with active substances that have mu-opioid receptor agonist activity should be carefully monitored for signs of abuse and addiction.

Respiratory Depression

At high doses or in mu-opioid receptor agonist sensitive patients, PALEXIA SR may produce dose-related respiratory depression. Therefore, PALEXIA SR should be administered with caution to patients with impaired respiratory functions. Alternative non-mu-opioid receptor agonist analgesics should be considered and PALEXIA SR should be employed only under careful medical supervision at the lowest effective dose in such patients. If respiratory depression occurs, it should be treated as any mu-opioid receptor agonist-induced respiratory depression.

Head Injury and Increased Intracranial Pressure

PALEXIA SR should not be used in patients who may be particularly susceptible to the intracranial effects of carbon dioxide retention such as those with evidence of increased intracranial pressure, impaired consciousness, or coma. Analgesics with mu-opioid receptor agonist activity may obscure the clinical course of patients with head injury. PALEXIA SR should be used with caution in patients with head injury and brain tumors.

Seizures

PALEXIA SR has not been systematically evaluated in patients with a seizure disorder, and such patients were excluded from clinical trials. However, like other analgesics with mu-opioid agonist activity PALEXIA SR is not recommended in patients with a history of a seizure disorder or any condition that would put the patient at risk of seizures.

Renal Impairment

PALEXIA SR has not been studied in controlled efficacy trials in patients with severe renal impairment, therefore the use in this population is not recommended.

Hepatic Impairment

Subjects with mild and moderate hepatic impairment showed a 2-fold and 4.5-fold increase in systemic exposure, respectively, compared with subjects with normal hepatic function. PALEXIA SR should be used with caution in patients with moderate hepatic impairment , especially upon initiation of treatment.

PALEXIA SR has not been studied in patients with severe hepatic impairment and therefore, use in this population is not recommended.

Use in Pancreatic/Biliary Tract Disease

Active substances with mu-opioid receptor agonist activity may cause spasm of the sphincter of Oddi. PALEXIA SR should be used with caution in patients with biliary tract disease, including acute pancreatitis.

Mixed opioid agonists/antagonists

Care should be taken when combining PALEXIA SR with mixed mu-opioid agonist/antagonists (like pentazocine, nalbuphine) or partial mu-opioid agonists (like buprenorphine). In patients maintained on buprenorphine for the treatment of opioid dependence, alternative treatment options (like e.g. temporary buprenorphine discontinuation) should be considered, if administration of full mu-agonists (like tapentadol) becomes necessary in acute pain situations. On combined use with buprenorphine, higher dose requirements for full mu-receptor agonists have been reported and close monitoring of adverse events such as respiratory depression is required in such circumstances.

PALEXIA SR prolonged-release tablets contain lactose. Patients with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption, should not take this medicinal product.

Effects on ability to drive and use machines

PALEXIA SR may have major influence on the ability to drive and use machines, because it may adversely affect central nervous system functions. This has to be expected especially at the beginning of treatment, when any change of dosage occur as well as in connection with the use of alcohol or tranquilisers. Patients should be cautioned as to whether driving or use of machines is permitted.

Dosage (Posology) and method of administration

Posology

The dosing regimen should be individualised according to the severity of pain being treated, the previous treatment experience and the ability to monitor the patient.

PALEXIA SR should be taken twice daily, approximately every 12 hours.

Initiation of therapy

Initiation of therapy in patients currently not taking opioid analgesics

Patients should start treatment with single doses of 50 mg tapentadol as prolonged-release tablet administered twice daily.

Initiation of therapy in patients currently taking opioid analgesics

When switching from opioids to PALEXIA SR and choosing the initial dose, the nature of the previous medicinal product, administration and the mean daily dose should be taken into account. This may require higher initial doses of PALEXIA SR for patients currently taking opioids compared to those not having taken opioids before initiating therapy with PALEXIA SR.

Titration and maintenance

After initiation of therapy the dose should be titrated individually to a level that provides adequate analgesia and minimises undesirable effects under the close supervision of the prescribing physician.

Experience from clinical trials has shown that a titration regimen in increments of 50 mg tapentadol as prolonged-release tablet twice daily every 3 days was appropriate to achieve

adequate pain control in most of the patients.

Total daily doses of PALEXIA SR greater than 500 mg tapentadol have not yet been studied and are therefore not recommended.

Discontinuation of treatment

Withdrawal symptoms could occur after abrupt discontinuation of treatment with tapentadol . When a patient no longer requires therapy with tapentadol, it is advisable to taper the dose gradually to prevent symptoms of withdrawal.

Renal Impairment

In patients with mild or moderate renal impairment a dosage adjustment is not required.

PALEXIA SR has not been studied in controlled efficacy trials in patients with severe renal impairment, therefore the use in this population is not recommended.

Hepatic Impairment

In patients with mild hepatic impairment a dosage adjustment is not required.

PALEXIA SR should be used with caution in patients with moderate hepatic impairment. Treatment in these patients should be initiated at the lowest available dose strength, i.e. 50 mg tapentadol as prolonged-release tablet, and not be administered more frequently than once every 24 hours. At initiation of therapy a daily dose greater than 50 mg tapentadol as prolonged-release tablet is not recommended. Further treatment should reflect maintenance of analgesia with acceptable tolerability.

PALEXIA SR has not been studied in patients with severe hepatic impairment and therefore, use in this population is not recommended.

Elderly patients (persons aged 65 years and over)

In general, a dose adaptation in elderly patients is not required. However, as elderly patients are more likely to have decreased renal and hepatic function, care should be taken in dose selection as recommended.

Paediatric Patients

The safety and efficacy of PALEXIA SR in children and adolescents below 18 years of age has not yet been established. Therefore PALEXIA SR is not recommended for use in this population.

Method of administration

PALEXIA SR has to be taken whole, not divided or chewed, to ensure that the prolonged-release mechanism is maintained. PALEXIA SR should be taken with sufficient liquid. PALEXIA SR can be taken with or without food.

The shell (matrix) of the tapentadol tablet may not be digested completely and therefore it can be eliminated and seen in the patient's stool. However, this finding has no clinical relevance, since the active substance of the tablet will have already been absorbed.

Special precautions for disposal and other handling

No special requirements.

Date of first authorisation/renewal of the authorisation

04 February 2011

Interaction with other medicinal products and other forms of interaction

Medicinal products like benzodiazepines, barbiturates and opioids (analgesics, antitussives or substitution treatments) may enhance the risk of respiratory depression if taken in combination with PALEXIA SR. CNS depressants (e.g. benzodiazepines, antipsychotics, H1-antihistamines, opioids, alcohol) can enhance the sedative effect of tapentadol and impair vigilance. Therefore, when a combined therapy of PALEXIA SR with a respiratory or CNS depressant is contemplated, the reduction of dose of one or both agents should be considered.

Mixed opioid agonists/antagonists

Care should be taken when combining PALEXIA SR with mixed mu-opioid agonist/antagonists (like pentazocine, nalbuphine) or partial mu-opioid agonists (like buprenorphine) (see also section 4.4).

In isolated cases there have been reports of serotonin syndrome in a temporal connection with the therapeutic use of tapentadol in combination with serotoninergic medicinal products such as selective serotonin re-uptake inhibitors (SSRIs). Signs of serotonin syndrome may be for example confusion, agitation, fever, sweating, ataxia, hyperreflexia, myoclonus and diarrhoea. Withdrawal of the serotoninergic medicinal products usually brings about a rapid improvement. Treatment depends on the nature and severity of the symptoms.

The major elimination pathway for tapentadol is conjugation with glucuronic acid mediated via uridine diphosphate transferase (UGT) mainly UGT1A6, UGT1A9 and UGT2B7 isoforms. Thus, concomitant administration with strong inhibitors of these isoenzymes (e.g. ketoconazole, fluconazole, meclofenamic acid) may lead to increased systemic exposure of tapentadol.

For patients on tapentadol treatment, caution should be exercised if concomitant drug administration of strong enzyme inducing drugs (e.g. rifampicin, phenobarbital, St John's Wort (hypericum perforatum)) starts or stops, since this may lead to decreased efficacy or risk for adverse effects, respectively

Treatment with PALEXIA SR should be avoided in patients who are receiving monoamine oxidase (MAO) inhibitors or who have taken them within the last 14 days due to potential additive effects on synaptic noradrenaline concentrations which may result in adverse cardiovascular events, such as hypertensive crisis.