Data Sheet
AROPAX™ Tablets
Paroxetine tablets
Presentation
AROPAX TABLETS: White, film coated, modified oval, biconvex tablets containing 22.8mg paroxetine hydrochloride equivalent to 20mg paroxetine free base.
The tablet has the product name and strength engraved on one side and a breakline on the reverse to enable the tablets to be broken in half if required.
Uses
Actions
Paroxetine is a potent and selective inhibitor of 5-hydroxytryptamine (5-HT, serotonin) uptake and its antidepressant action and effectiveness in the treatment of OCD and Panic Disorder is thought to be related to its specific inhibition of 5-HT uptake in brain neurones.
Paroxetine is chemically unrelated to the tricyclic, tetracyclic and other available antidepressants.
Paroxetine has low affinity for muscarinic cholinergic receptors and animal studies have indicated only weak anticholinergic properties.
In accordance with this selective action, in vitro studies have indicated that, in contrast to tricyclic antidepressants, paroxetine has little affinity for alpha1, alpha2 and beta-adrenoceptors, dopamine (D2), 5-HT1 like, 5-HT2 and histamine (H1) receptors. This lack of interaction with post-synaptic receptors in vitro is substantiated by in vivo studies, which demonstrate lack of CNS depressant and hypotensive properties.
Pharmacodynamic effects
Paroxetine does not impair psychomotor function and does not potentiate the depressant effects of ethanol.
As with other selective 5-HT uptake inhibitors, paroxetine causes symptoms of excessive 5-HT receptor stimulation when administered to animals previously given monoamine oxidase (MAO) inhibitors or tryptophan.
Behavioural and EEG studies indicate that paroxetine is weakly activating at doses generally above those required to inhibit 5-HT uptake. The activating properties are not ""amphetamine-like"" in nature.
Animal studies indicate that paroxetine is well tolerated by the cardiovascular system.
Paroxetine produces no clinically significant changes in blood pressure, heart rate and ECG after administration to healthy subjects.
Studies indicate that, in contrast to antidepressants, which inhibit the uptake of nor-adrenaline, paroxetine has a much reduced propensity to inhibit the antihypertensive effects of guanethidine.
Pharmacokinetics
Absorption
Paroxetine is well absorbed after oral dosing and undergoes first-pass metabolism.
Due to first-pass metabolism, the amount of paroxetine available to the systemic circulation is less than that absorbed from the gastrointestinal tract. Partial saturation of the first-pass effect and reduced plasma clearance occur as the body burden increases with higher single doses or on multiple dosing. This results in disproportionate increases in plasma concentrations of paroxetine and hence pharmacokinetic parameters are not constant, resulting in non-linear kinetics. However, the non-linearity is generally small and is confined to those subjects who achieve low plasma levels at low doses.
Steady state systemic levels are attained by 7-14 days after starting treatment and pharmacokinetics do not appear to change during long-term therapy.
Distribution
Paroxetine is extensively distributed into tissues and pharmacokinetic calculations indicate that only 1% of the paroxetine in the body resides in the plasma.
Approximately 95% of the paroxetine present in the plasma is protein bound at therapeutic concentrations.
No correlation has been found between paroxetine plasma concentrations and clinical effect (adverse experiences and efficacy).
Metabolism
The principal metabolites of paroxetine are polar and conjugated products of oxidation and methylation which are readily cleared. In view of their relative lack of pharmacological activity, it is most unlikely that they contribute to paroxetine''s therapeutic effects.
Metabolism does not compromise paroxetine''s selective action on neuronal 5-HT uptake.
Elimination
About 64% of the dose is excreted in the urine; urinary excretion of unchanged paroxetine is generally less than 2% of the dose. About 36% of the dose is excreted in the faeces, probably via the bile; faecal excretion of unchanged paroxetine represents less than 1% of the dose. Thus paroxetine is eliminated almost entirely by metabolism.
Metabolite excretion is biphasic, being initially a result of first-pass metabolism and subsequently controlled by systemic elimination of paroxetine.
The elimination half-life is variable but is generally about 1 day.
Special Patient Populations
Elderly and Renal/Hepatic Impairment
Increased plasma concentrations of paroxetine occur in elderly subjects and in those subjects with severe renal and hepatic impairment, but the range of plasma concentrations overlaps that of healthy adult subjects.
Indications
Adults
Depression:
Depression of all types, including reactive and severe depression and depression accompanied by anxiety.
AROPAX is indicated for the prevention of relapse and also recurrence of further depressive episodes.
In the treatment of depressive disorders, AROPAX exhibits comparable efficacy to standard antidepressants.
In general, improvement in patients starts after one week but does not become superior to placebo until the second week of therapy.
AROPAX, in addition to its significant antidepressant effects, also improves associated symptoms of anxiety.
There is also some evidence that AROPAX may be of therapeutic value in patients who have failed to respond to standard therapy.
Morning dosing with AROPAX does not have any detrimental effect on either the quality or duration of sleep. Moreover, patients are likely to experience improved sleep as they respond to AROPAX therapy.
Where it is clinical practice to co-prescribe short-acting hypnotics with antidepressants, no additional adverse events have been recorded.
AROPAX is effective in improving depression and suicidal ideation concurrently during the first few weeks of therapy.
Long term treatment with AROPAX has shown that efficacy is maintained for periods of at least one year.
Obsessive Compulsive Disorder:
AROPAX is indicated for the treatment of Obsessive Compulsive Disorder (OCD).
In a placebo-controlled trial, the efficacy of AROPAX in the treatment of OCD has been maintained for at least 1 year.
Panic Disorder:
AROPAX is indicated for the treatment of Panic Disorder with and without agoraphobia.
The combination of AROPAX and cognitive-behavioural therapy has been shown to be significantly more effective than cognitive-behavioural therapy alone in the treatment of Panic Disorder.
In a placebo-controlled trial, the efficacy of AROPAX in the treatment of Panic Disorder has been maintained for up to 1 year.
Social Anxiety Disorder/Social Phobia:
AROPAX has been shown to be effective in the treatment of Social Anxiety Disorder/Social Phobia.
Generalised Anxiety Disorder:
AROPAX has been shown to be effective in the treatment of Generalised Anxiety Disorder.
In a placebo-controlled trial, the efficacy of AROPAX in the treatment of Generalised Anxiety Disorder has been maintained for up to 32 weeks.
Posttraumatic Stress Disorder:
AROPAX has been shown to be effective in the treatment of Post-traumatic Stress Disorder.
ALL INDICATIONS
Children and adolescents (<18 years)
AROPAX is not indicated for use in children or adolescents aged <18 years (see Warnings and Precautions).
Controlled clinical studies in children and adolescents with major depressive disorder failed to demonstrate efficacy, and do not support the use of AROPAX in the treatment of depression in this population (see Warnings and Precautions).
The safety and efficacy of AROPAX in children aged <7 years has not been studied.
Dosage and Administration
Adults
It is recommended that paroxetine is administered once daily in the morning with food. The tablet should be swallowed rather than chewed.
Depression:
The recommended dose is 20mg daily. Some patients not responding to a 20mg dose may benefit from dose increases, in 10mg/day increments, up to a maximum of 50mg/day. It is recommended that AROPAX is administered once daily with food. Based on observed beneficial effects on sleep it is recommended that the dose be taken in the morning. If, however, a patient experiences unacceptable daytime somnolence with AROPAX, consideration should be given to dosing at bedtime. The tablet should be swallowed rather than chewed.
As with all antidepressant drugs, dosage should be reviewed and adjusted if necessary within 2 to 3 weeks of initiation of therapy and thereafter as judged clinically appropriate. Dose changes should occur at intervals of at least one week.
Patients with depression should be treated for a sufficient period to ensure that they are free from symptoms. This period may be several months.
Obsessive Compulsive Disorder:
The recommended dose is 40mg (2 tablets) daily. Patients should start on 20mg and the dose can be increased weekly in 10mg increments. Some patients will benefit from having their dose increased up to a maximum of 60mg/day.
It is recommended that AROPAX is administered once daily with food. The tablet should be swallowed rather than chewed.
Patients with OCD should be treated for a sufficient period to ensure that they are free from symptoms. This period may be several months or even longer.
Panic Disorder:
The recommended dose is 40mg daily. Patients should be started on 10mg/day and the dose increased weekly in 10mg increments according to patient's response. Some patients may benefit from having their dose increased up to a maximum of 60mg/day.
A low initial starting dose is recommended to minimise the potential worsening of panic symptomatology, which is generally recognised to occur early in the treatment of this disorder.
Patients with panic disorder should be treated for a sufficient period to ensure that they are free from symptoms. This period may be several months or even longer.
Social Anxiety Disorder/Social Phobia:
The recommended dose is 20mg daily. Some patients not responding to a 20mg dose may benefit from having dose increases in 10mg increments as required, up to a maximum of 50mg/day according to the patient's response.
Generalised Anxiety Disorder:
The recommended dose is 20mg daily. Some patients not responding to a 20mg dose may benefit from having dose increases in 10mg increments as required, up to a maximum of 50mg/day according to the patient''s response.
Posttraumatic Stress Disorder:
For the majority of patients, the recommended starting and maintenance dose is 20mg daily. However, some patients not responding to a 20mg dose may benefit from having dose increases in 10mg increments as required, up to a maximum of 50mg/day according to the patient''s response.
The use of AROPAX beyond 12 weeks has not been investigated in clinical trials.
Populations
Elderly: Increased plasma concentrations of AROPAX occur in elderly subjects, but the range of concentrations overlaps with that observed in younger subjects.
Children and adolescents (<18 years)
AROPAX is not indicated for use in children or adolescents aged <18 years (see Indications and Warnings and Precautions).
Renal/Hepatic Impairment: Increased plasma concentrations of AROPAX occur in patients with severe renal impairment (creatinine clearance <30mL/min) or hepatic impairment. Therefore, dosage should be restricted to the lower end of the dosage range.
Discontinuation of AROPAX
As with other psychoactive medications, abrupt discontinuation should generally be avoided (see Warnings and Precautions & Adverse Effects sections). The taper phase regimen used in recent clinical trials involved a decrease in the daily dose by 10 mg/day at weekly intervals. When a daily dose of 20 mg/day was reached, patients were continued on this dose for one week before treatment was stopped. If intolerable symptoms occur following a decrease in the dose or upon discontinuation of treatment, then resuming the previously prescribed dose may be considered. Subsequently, the physician may continue decreasing the dose, but at a more gradual rate.
Contraindications
Known hypersensitivity to paroxetine and excipients.
Paroxetine should not be used in combination with monoamine oxidase (MAO) inhibitors (including linezolid, an antibiotic which is a reversible non-selective MAO inhibitor) or within 2 weeks of terminating treatment with MAO inhibitors. Likewise, MAO inhibitors should not be introduced within 2 weeks of cessation of therapy with paroxetine (see Interactions).
Paroxetine should not be used in combination with monoamine oxidase (MAO) inhibitors or within 2 weeks of terminating treatment with MAO inhibitors. Likewise, MAO inhibitors should not be introduced within 2 weeks of cessation of therapy with paroxetine (see Interactions)
Paroxetine should not be used in combination with thioridazine, because, as with other drugs, which inhibit the hepatic enzyme CYP450 2D6, paroxetine can elevate plasma levels of thioridazine (see Interactions). Administration of thioridazine alone can lead to QTc interval prolongation with associated serious ventricular arrhythmia such as torsades de pointes, and sudden death.
Paroxetine should not be used in combination with pimozide (see Interactions).
Warnings and Precautions
Children and Adolescents (<18 years): Treatment with antidepressants is associated with an increased risk of suicidal thinking and behaviour in children and adolescents with major depressive disorder and other psychiatric disorders. In clinical trials of AROPAX in children and adolescents, adverse events related to suicidality (suicide attempts and suicidal thoughts) and hostility (predominantly aggression, oppositional behaviour and anger) were more frequently observed in patients treated with AROPAX compared to those treated with placebo (see Adverse Reactions). Long-term safety data in children and adolescents concerning growth, maturation and cognitive and behavioural development are lacking.
Clinical worsening and suicide risk in adults:
Young adults, especially those with MDD, may be at increased risk for suicidal behaviour during treatment with paroxetine. An analysis of placebo controlled trials of adults with psychiatric disorders showed a higher frequency of suicidal behaviour in young adults (prospectively defined as aged 18-24 years) treated with paroxetine compared with placebo (17/776 [2.19%] versus 5/542 [0.92%]), although this difference was not statistically significant. In the older age groups (aged 25-64 years and ≥65 years), no such increase was observed. In adults with MDD (all ages), there was a statistically significant increase in the frequency of suicidal behaviour in patients treated with paroxetine compared with placebo (11/3455 [0.32%] versus 1/1978 [0.05%]; all of the events were suicide attempts). However, the majority of these attempts for paroxetine (8 of 11) were in younger adults aged 18-30 years. These MDD data suggest that the higher frequency observed in the younger adult population across psychiatric disorders may extend beyond the age of 24.
The possibility of a suicide attempt is an inherent component of major depressive disorder and may persist until significant remission occurs. Patients with depression may experience worsening of their depressive symptoms and/or the emergence of suicidal ideation and behaviours (suicidality) whether or not they are taking antidepressant medications. This risk persists until significant remission occurs. It is general clinical experience with all antidepressant therapies that the risk of suicide may increase in the early stages of recovery.
Other psychiatric conditions for which paroxetine is prescribed can be associated with an increased risk of suicidal behaviour, and these conditions may be co-morbid with MDD.
Additionally patients with a history of suicidal behaviour or thoughts, young adults, and those patients exhibiting a significant degree of suicidal ideation prior to commencement of treatment, are at a greater risk of suicidal thoughts or suicide attempts. All patients should be monitored for clinical worsening (including development of new symptoms) and suicidality throughout treatment, and especially at the beginning of a course of treatment, or at the time of dose changes, either increases or decreases.
Patients, (and caregivers of patients) should be alerted about the need to monitor for any worsening of their condition (including development of new symptoms) and/or the emergence of suicidal ideation/behaviour or thoughts of harming themselves and to seek medical advice immediately if these symptoms present. It should be recognised that the onset of some symptoms, such as agitation, akathisia or mania, could be related either to the underlying disease state or the drug therapy (see Akathisia and Mania and Bipolar Disorder below; Adverse Reactions).
Consideration should be given to changing the therapeutic regimen, including possibly discontinuing the medication, in patients who experience clinical worsening (including development of new symptoms) and/or the emergence of suicidal ideation/behaviour, especially if these symptoms are severe, abrupt in onset, or were not part of the patient's presenting symptoms.
Akathisia: Rarely, the use of paroxetine or other SSRIs has been associated with the development of akathisia, which is characterised by an inner sense of restlessness and psychomotor agitation such as an inability to sit or stand still usually associated with subjective distress. This is most likely to occur within the first few weeks of treatment.
Serotonin Syndrome/Neuroleptic Malignant Syndrome: On rare occasions development of a serotonin syndrome or neuroleptic malignant syndrome-like events may occur in association with treatment of paroxetine, particularly when given in combination with other serotonergic and/or neuroleptic drugs. As these syndromes may result in potentially life-threatening conditions, treatment with paroxetine should be discontinued if such events (characterised by clusters of symptoms such as hyperthermia, rigidity, myoclonus, autonomic instability with possible rapid fluctuations of vital signs, mental status changes including confusion, irritability, extreme agitation progressing to delirium and coma) occur and supportive symptomatic treatment should be initiated. Paroxetine should not be used in combination with serotonin-precursors (such as L-tryptophan, oxitriptan) due to the risk of serotonergic syndrome (see Contraindications and Interactions).
Mania and Bipolar disorder: A major depressive episode may be the initial presentation of bipolar disorder. It is generally believed (though not established in controlled trials) that treating such an episode with an antidepressant alone can increase the likelihood of precipitation of a mixed/manic episode in patients at risk for bipolar disorder. Prior to initiating treatment with an antidepressant, patients should be adequately screened to determine if they are at risk for bipolar disorder; such screening should include a detailed psychiatric history, including a family history of suicide, bipolar disorder, and depression. It should be noted that paroxetine is not approved for use in treating bipolar depression. As with all antidepressants, paroxetine should be used with caution in patients with a history of mania.
Bone Fracture: Epidemiological studies on bone fracture risk following exposure to some antidepressants, including SSRIs, have reported an association with fractures. The risk occurs during treatment and is greatest in the early stages of therapy. The possibility of fracture should be considered in the care of patients treated with paroxetine.
MAO Inhibitors: Treatment with paroxetine should be initiated cautiously at least 2 weeks after terminating treatment with MAO inhibitors and dosage of paroxetine should be increased gradually until optimal response is reached (see Contraindications and Interactions).
Cardiac Conditions: The usual precautions should be observed in patients with cardiac conditions.
Epilepsy: As with other antidepressants, paroxetine should be used with caution in patients with epilepsy.
Seizures: Overall the incidence of seizures is less than 0.1% in patients treated with paroxetine.
Paroxetine should be discontinued in any patient who develops seizures.
ECT: There is little clinical experience of the concurrent administration of paroxetine with ECT.
Glaucoma: As with other SSRIs, paroxetine can cause mydriasis and should be used with caution in patients with narrow angle glaucoma.
Renal/hepatic impairment: Caution is recommended in patients with severe renal impairment or in those with hepatic impairment. (See Dosage and Administration).
Hyponatraemia: Hyponatraemia has been reported rarely, predominantly in the elderly. The hyponatraemia generally reverses on discontinuation of paroxetine.
Haemorrhage: Bleeding abnormalities of the skin and mucous membranes have been reported with the use of SSRIs (including purpura, haematoma, epistaxis, vaginal bleeding and gastrointestinal bleeding). This risk may be potentiated by concurrent use of non-steroidal anti-inflammatory drugs (NSAIDs), aspirin or other medicines that affect coagulation. Aropax should therefore be used with caution in patients concomitantly treated with medicines that increase the risk of bleeding or in patients with a past history of abnormal bleeding or those with predisposing conditions. Pharmacological gastroprotection should be considered for high risk patients.
Symptoms seen on discontinuation of paroxetine treatment in adults: In clinicals trials in adults, adverse events seen on treatment discontinuation occurred in 30% of patients treated with paroxetine compared to 20% of patients treated with placebo. The occurrence of discontinuation symptoms is not the same as the drug being addictive or dependence producing as with a substance of abuse.
Dizziness, sensory disturbances (including paraesthesia and electric shock sensations), sleep disturbances (including intense dreams), agitation or anxiety, nausea, tremor, confusion, sweating, headache, diarrhoea have been reported. Generally these symptoms are mild to moderate, however, in some patients they may be severe in intensity. They usually occur within the first few days of discontinuing treatment, but there have been very rare reports of such symptoms in patients who have inadvertently missed a dose. Generally these symptoms are self-limiting and usually resolve within 2 weeks, though in some individuals they may be prolonged (2-3 months or more). It is therefore advised that paroxetine should be gradually tapered when discontinuing treatment over a period of several weeks or months, according to the patient''s needs (see ""Discontinuation of Paroxetine"", Dosage and Administration).
Symptoms seen on discontinuation of paroxetine treatment in children and adolescents: In clinical trials in children and adolescents, adverse events seen on treatment discontinuation occurred in 32% of patients treated with paroxetine compared to 24% of patients treated with placebo. Events reported upon discontinuation of paroxetine at a frequency of at least 2% of patients and which occurred at a rate at least twice that of placebo were: emotional lability (including suicidal ideation, suicide attempt, mood changes and tearfulness), nervousness, dizziness, nausea and abdominal pain (see Adverse Effects).
Fertility
Some clinical studies have shown that SSRIs (including paroxetine) may affect sperm quality. This effect appears to be reversible following discontinuation of treatment. Changes in sperm quality may affect fertility in some men.
Pregnancy and Lactation
Paroxetine should not be used during pregnancy, unless the potential benefit outweighs the possible risk. The prescribing physician will need to weigh the option of alternative treatments in women who are pregnant or are planning to become pregnant.
If a decision is taken to discontinue paroxetine treatment in a pregnant woman, the prescriber should consult Dosage and Administration - Discontinuation of Paroxetine and Warnings and Precautions - Symptoms seen on discontinuation of paroxetine treatment in adults.
Epidemiological studies have shown infants born to women who had first trimester paroxetine exposure had an increased risk of cardiovascular malformations.
A recent retrospective US epidemiological study of 5,956 infants born to women exposed to paroxetine or other antidepressants during the first trimester of pregnancy showed an increased risk of major congenital malformations overall for paroxetine compared to other antidepressants (odds ratio1.8; 95% confidence interval1.2 - 2.8). There was also an increased risk of cardiovascular malformations for paroxetine compared to other antidepressants (odds ratio1.5; 95% confidence interval 0.8 - 2.9). These figures excluded women exposed to both antidepressants and teratogenic drugs. The majority of cardiovascular malformations were ventricular septal defects.
The prevalence of congenital malformations as a whole and cardiovascular malformation alone in these infants was 4% and 1.5% for paroxetine versus. 2% and 1% for other antidepressants respectively. These rates compare with those in the general population of 3% for all congenital malformation and 1% for cardiovascular malformation. [Centers for Disease Control and Prevention, USA and Metropolitan Atlanta Birth Congenital Defects Program Data (MACDP)].
A study based on the Swedish Medical Birth Register evaluated infants of 6,896 women exposed to antidepressants in early pregnancy (5,123 women exposed to SSRI's including 815 for paroxetine). Infants exposed to paroxetine in early pregnancy had an increased risk of cardiovascular malformations compared to the entire registry population (odds ratio 1.8; 95% confidence interval 1.1 - 2.8). The rate of cardiovascular malformations following early pregnancy paroxetine exposure was approximately 2% versus 1% in the entire registry population. No increase in the overall risk for congenital malformations was observed in these infants exposed to paroxetine.
Neonates should be observed if maternal use of paroxetine continues into the later stages of pregnancy, because there have been reports of complications in neonates exposed to paroxetine or other SSRIs late in the third trimester of pregnancy. However, a causal association with drug therapy has not been confirmed. Reported clinical findings have included: respiratory distress, cyanosis, apnoea, seizures, temperature instability, feeding difficulty, vomiting, hypoglycemia, hypertonia, hypotonia, hyperreflexia, tremor, jitteriness, irritability, lethargy, constant crying and somnolence. In some instances the reported symptoms were described as neonatal withdrawal symptoms. In a majority of instances the complications were reported to have arisen either immediately or soon (<24 hours) after delivery.
Epidemiological studies have shown that the use of SSRIs (including paroxetine) in pregnancy, particularly use in late pregnancy, was associated with an increased risk of persistent pulmonary hypertension of the newborn (PPHN). The increased risk among infants born to women who used SSRIs late in pregnancy was reported to be 4 to 5 times higher than observed in the general population (rate of 1 to 2 per 1000 pregnancies).
Animal studies have not shown any teratogenic or selective embryotoxic effects, and data on a limited number of exposed pregnancies in humans provide no indication of an increased risk of congenital malformations in the newborn. There have been reports of premature birth in pregnant women exposed to paroxetine or others SSRIs, although a causal relationship with drug therapy has not been established. Paroxetine should not be used during pregnancy unless the potential benefit outweighs the possible risk.
Small amounts of paroxetine are excreted into breast milk. In published studies, serum concentrations in breast-fed infants were undetectable (<2 ng/ml) or very low (<4 ng/ml). No signs of drug effects were observed in these infants. Nevertheless, paroxetine should not be used during lactation unless the expected benefits to the mother justify the potential risks for the infant.
Effects on Ability to Drive and Use Machines
Clinical experience has shown that therapy with paroxetine is not associated with impairment of cognitive or psychomotor function. However, as with all psychoactive drugs, patients should be cautioned about their ability to drive a car and operate machinery.
Although paroxetine does not increase the mental and motor skill impairments caused by alcohol, the concomitant use of paroxetine and alcohol is not advised.
Other: Preclinical Safety Data
Toxicology studies have been conducted in rhesus monkeys and albino rats; in both, the metabolic pathway is similar to that described for humans. As expected with lipophilic amines, including tricyclic antidepressants, phospholipidosis was detected in rats. Phospholipidosis was not observed in primate studies of up to one year duration at doses that were 6 times higher than the recommended range of clinical doses.
Carcinogenesis: In two-year studies conducted in mice and rats, paroxetine had no tumorigenic effect.
Genotoxicity: Genotoxicity was not observed in a battery of in vitro and in vivo tests.
The patient has the right to treatment meeting appropriate ethical and professional standards, and the patient needs to be fully informed with frank discussion of risk/benefit issues relating to this medicine's efficacy and safety when used in the treatment regimen proposed.
Adverse Effects
Some of the adverse experiences listed below may decrease in intensity and frequency with continued treatment and do not generally lead to cessation of therapy. Adverse drug reactions are listed below by system organ class and frequency. Frequencies are defined as: very common (≥ 1/10), common (≥ 1/100, <1/10), uncommon (≥ 1/1,000, <1/100), rare (≥ 1/10,000, <1/1,000), very rare (<1/10,000), including isolated reports. The frequencies of common and uncommon events were generally determined from pooled safety data from a clinical trial population of >8000 paroxetine-treated patients and are quoted as excess incidence over placebo. Rare and very rare events were generally determined from post-marketing data and refer to reporting rate rather than true frequency.
Blood & lymphatic system disorders
Uncommon: abnormal bleeding, predominantly of the skin and mucous membranes
(including ecchymosis, purpura, haematomas, and very rarely epistaxis, vaginal
bleeding and gastrointestinal bleeding).
Very rare: thrombocytopenia.
Immune system disorders
Very rare: allergic reactions (including urticaria and angioedema).
Endocrine disorders
Very rare: syndrome of inappropriate anti-diuretic hormone secretion (SIADH).
Metabolism & nutrition disorders
Common: decreased appetite.
Rare: hyponatraemia.
Hyponatraemia has been reported predominantly in elderly patients and is sometimes due to syndrome of inappropriate anti-diuretic hormone secretion (SIADH).
Psychiatric disorders
Common: somnolence, insomnia, agitation, abnormal dreams (including
nightmares).
Uncommon: confusion, hallucinations.
Rare: manic reactions.
These symptoms may be due to the underlying disease.
Nervous system disorders
Common: dizziness, tremor, headache.
Uncommon: extrapyramidal disorders.
Rare: convulsions, akathisia, restless legs syndrome (RLS).
Very rare: serotonin syndrome (symptoms may include agitation, confusion,
diaphoresis, hallucinations, hyperreflexia, myoclonus, shivering tachycardia
and tremor).
Reports of extrapyramidal disorders including oro-facial dystonia have been received in patients sometimes with underlying movement disorders or who were using neuroleptic medication.
Eye disorders
Common: blurred vision.
Uncommon: mydriasis (see Warnings and Precautions).
Very rare: acute glaucoma.
Cardiac disorders
Uncommon: sinus tachycardia
Vascular disorders
Uncommon: postural hypotension.
Respiratory, thoracic and mediastinal disorders
Common: yawning.
Gastrointestinal disorders
Very common: nausea.
Common: constipation, diarrhoea, vomiting, dry mouth.
Very rare: gastrointestinal bleeding.
Hepato-biliary disorders
Rare: elevation of hepatic enzymes.
Very rare: hepatic events (such as hepatitis, sometimes associated with
jaundice and/or liver failure).
Elevation of hepatic enzymes has been reported. Post-marketing reports of hepatic events (such as hepatitis, sometimes associated with jaundice, and/or liver failure) have also been received very rarely. Discontinuation of paroxetine should be considered if there is prolonged elevation of liver function test results.
Skin & subcutaneous tissue disorders
Common: sweating.
Uncommon: skin rashes.
Very rare: photosensitivity reactions.
Renal & urinary disorders
Uncommon: urinary retention, urinary incontinence.
Reproductive system & breast disorders
Very common: sexual dysfunction.
Rare: hyperprolactinaemia / galactorrhoea.
General disorders & administration site conditions
Common: asthenia.
Very rare: peripheral oedema.
Symptoms seen on discontinuation of paroxetine treatment
Common: Dizziness, sensory disturbances, sleep disturbances, anxiety,
headache.
Uncommon: Agitation, nausea, tremor, confusion, sweating, diarrhoea.
As with many psychoactive medicines, discontinuation of paroxetine (particularly when abrupt) may lead to symptoms such as dizziness, sensory disturbances (including paraesthesia, electric shock sensations and tinnitus), sleep disturbances (including intense dreams), agitation or anxiety, nausea, headache, tremor, confusion, diarrhoea and sweating. In the majority of patients, these events are mild to moderate and are self-limiting. No particular patient group appears to be at higher risk of these symptoms; it is therefore advised that when paroxetine treatment is no longer required, gradual discontinuation by dose tapering be carried out (see Dosage and Administration & Warnings and Precautions).
Adverse Events from Paediatric Clinical Trials
In paediatric clinical trials the following adverse events were reported at a frequency of at least 2% of patients and occurred at a rate at least twice that of placebo: emotional lability (including self-harm, suicidal thoughts, attempted suicide crying and mood fluctuations), hostility, decreased appetite, tremor, sweating, hyperkinesia and agitation. Suicidal thoughts and suicide attempts were mainly observed in clinical trials of adolescents with Major Depressive Disorder. Hostility occurred particularly in children with obsessive compulsive disorder and especially in younger children (less than 12 years of age).
In studies that used a tapering regimen (daily dose decreased by 10 mg/day at weekly intervals to a dose of 10 mg/day for one week), symptoms reported during the taper phase or upon discontinuation of paroxetine at a frequency of at least 2% of patients and occurred at a rate at least twice that of placebo were: emotional lability, nervousness, dizziness, nausea, and abdominal pain (see Warnings and Precautions).
Interactions
Interactive Effects on Paroxetine
Clinical studies have shown the absorption and pharmacokinetics of paroxetine to be unaffected or only marginally affected (i.e. at a level which warrants no change in dosing regimen) by:
- food
- antacids
- digoxin
- propranolol
- alcohol: paroxetine does not increase the impairment of mental and motor skills caused by alcohol, however, the concomitant use of paroxetine and alcohol is not advised.
Serotonergic drugs
As with other SSRIs, co-administration with serotonergic drugs may lead to an
incidence of 5-HT associated effects (serotonin syndrome: see and Warnings and
Precautions). Caution should be advised and a closer clinical monitoring is
required when serotonergic drugs (such as L-tryptophan, triptans, tramadol,
SSRIs, lithium, fentanyl and St. John''s Wort - Hypericum perforatum -
preparations) are combined with paroxetine. Concomitant use of paroxetine and
MAO inhibitors (including linezolid, an antibiotic which is a reversible
non-selective MAO inhibitor) is contraindicated (see Contraindications).
Pimozide
Increased pimozide levels have been demonstrated in a study of a single low
dose pimozide (2 mg) when co-administered with paroxetine. This is explained
by the known CYP2D6 inhibitory properties of paroxetine. Due to the narrow
therapeutic index of pimozide and its known ability to prolong QT interval,
concomitant use of pimozide and paroxetine is contraindicated (see
Contraindications).
Drug metabolising enzymes
The metabolism and pharmacokinetics of paroxetine may be affected by the
induction or inhibition of drug metabolising enzymes.
When paroxetine is to be co-administered with a known drug metabolising enzyme inhibitor, consideration should be given to using doses at the lower end of the range.
No initial dosage adjustment is considered necessary when the drug is to be co-administered with known drug metabolising enzyme inducers (e.g. carbamazepine, rifampicin, phenobarbital, phenytoin). Any subsequent dosage adjustment should be guided by clinical effect (tolerability and efficacy).
Fosamprenavir/ritonavir: Co-administration of fosamprenavir/ritonavir with paroxetine significantly decreased plasma levels of paroxetine. Any dose adjustment should be guided by clinical effect (tolerability and efficacy).
Procyclidine: Daily administration of paroxetine increases significantly the plasma levels of procyclidine. If anti-cholinergic effects are seen, the dose of procyclidine should be reduced.
Anticonvulsants: carbamazepine, phenytoin, sodium valproate. Concomitant administration does not seem to show any effect on pharmacokinetic/dynamic profile in epileptic patients.
CYP2D6 inhibitory potency of paroxetine: As with other antidepressants, including other SSRIs, paroxetine inhibits the hepatic cytochrome P450 enzyme CYP2D6. Inhibition of CYP2D6 may lead to increased plasma concentrations of co-administered drugs metabolised by this enzyme. These include certain tricyclic antidepressants (e.g. amitriptyline, nortriptyline, imipramine and desipramine), phenothiazine neuroleptics (e.g. perphenazine and thioridazine, see Contraindications), risperidone, atomoxetine, certain Type 1c antiarrhythmics (e.g. propafenone and flecainide) and metoprolol.
Tamoxifen is a pro-drug requiring metabolic activation by CYP2D6. Inhibition of CYP2D6 by paroxetine may lead to reduced plasma concentrations of an active metabolite and hence reduced efficacy of tamoxifen.
CYP3A4: An in vivo interaction study involving the co-administration under steady state conditions of paroxetine and terfenadine, a substrate for cytochrome CYP3A4, revealed no effect of paroxetine on terfenadine pharmacokinetics. A similar in vivo interaction study revealed no effect of paroxetine on alprazolam pharmacokinetics and vice-versa. Concurrent administration of paroxetine with terfenadine, alprazolam and other drugs that are CYP3A4 substrates would not be expected to cause a hazard.
Medicines that interfere with haemostasis (NSAIDs, aspirin, warfarin etc.): Serotonin release by platelets plays an important role in haemostasis. There is an association between use of psychotropic drugs that interfere with serotonin reuptake and the occurrence of abnormal bleeding. Concurrent use of an NSAID, aspirin or warfarin potentiates this risk. Thus, patients should be cautioned about using such medicines concurrently with Aropax.
Overdosage
Symptoms and Signs
A wide margin of safety is evident from available overdose information on paroxetine.
Experience of paroxetine in overdose has indicated that, in addition to those symptoms mentioned under "Adverse effects", fever, blood pressure changes, involuntary muscle contractions, anxiety and tachycardia have been reported.
Patients have generally recovered without serious sequelae even when doses of up to 2000mg have been taken alone. Events such as coma or ECG changes have occasionally been reported and, very rarely a fatal outcome, but generally when paroxetine was taken in conjunction with other psychotropic drugs, with or without alcohol.
Treatment
No specific antidote is known.
The treatment should consist of those general measures employed in the management of overdose with any antidepressant. Supportive care with frequent monitoring of vital signs and careful observation is indicated. Patient management should be as clinically indicated, or as recommended by the national poisons centre, where available.
Pharmaceutical Precautions
Incompatibilities
There are no known incompatibilities with paroxetine tablets. The tablet should be swallowed whole, not chewed.
Shelf Life
2 years when stored below 30°C.
Special Precautions for Storage
Tablets: Store in a dry place at a temperature not exceeding 30°C.
Medicines Classification
Prescription Only Medicine
Package Quantities
AROPAX, 20mg: 30 tablet packs (blisters in strips containing 10 tablets).
Name and Address
GlaxoSmithKline NZ Limited
AMP Centre
Cnr Albert & Customs Streets
Private Bag 106600
Downtown Auckland
NEW ZEALAND
Phone: (09) 367 2900
Facsimile: (09) 367 2506
Date of Preparation
Version 2.0
Issue date: 9 September 2009
AROPAX™ is a trademark of the GlaxoSmithKline group of companies.