1. Name Of The Medicinal Product
Topamax®
Topamax®
Topamax®
Topamax®
Topamax®
Topamax®
Topamax®
2. Qualitative And Quantitative Composition
Topamax film-coated tablets:
One tablet contains 25, 50, 100 or 200 mg of topiramate.
Excipients: also includes lactose monohydrate:
25 mg tablet contains 31 mg lactose monohydrate;
50 mg tablet contains 62 mg lactose monohydrate;
100 mg tablet contains 123 mg lactose monohydrate;
200 mg tablet contains 44 mg lactose monohydrate.
Topamax Sprinkle hard capsules:
One capsule contains 15, 25 or 50 mg of topiramate.
Excipients: also includes sugar spheres containing not less than 62.5% and not more than 91.5% of sucrose:
One 15 mg capsule contains between 28.1 and 41.2 mg sucrose
One 25 mg capsule contains between 46.8 and 68.6 mg sucrose
One 50 mg capsule contains between 93.7 and 137.2 mg sucrose
For a full list of excipients, see section 6.1.
3. Pharmaceutical Form
Topamax film-coated tablets:
Film-coated tablets.
Description of the product.
25 mg tablet: white round tablets, 6 mm in diameter, “TOP” on one side, “25” on the other.
50 mg tablet: light yellow round tablets, 7 mm in diameter, “TOP” on one side, “50” on the other.
100 mg tablet: yellow round tablets, 9 mm in diameter, “TOP” on one side, “100” on the other.
200 mg tablet: salmon round tablets, 10 mm in diameter, “TOP” on one side, “200” on the other.
Topamax Sprinkle hard capsules:
Hard capsules.
Description of the product.
15 mg capsules: small white to off-white spheres in Size 2 hard gelatin capsules with white opaque body marked '15 mg' and clear cap marked 'TOP'.
25 mg capsules: small white to off-white spheres in Size 1 hard gelatin capsules with white opaque body marked '25 mg' and clear cap marked 'TOP'.
50 mg capsules: small white to off-white spheres in Size 0 hard gelatin capsules with white opaque body marked '50 mg' and clear cap marked 'TOP'.
4. Clinical Particulars
4.1 Therapeutic Indications
Monotherapy in adults, adolescents and children over 6 years of age with partial seizures with or without secondary generalised seizures, and primary generalised tonic-clonic seizures.
Adjunctive therapy in children aged 2 years and above, adolescents and adults with partial onset seizures with or without secondary generalization or primary generalized tonic-clonic seizures and for the treatment of seizures associated with Lennox-Gastaut syndrome.
Topiramate is indicated in adults for the prophylaxis of migraine headache after careful evaluation of possible alternative treatment options. Topiramate is not intended for acute treatment.
4.2 Posology And Method Of Administration
General
It is recommended that therapy be initiated at a low dose followed by titration to an effective dose. Dose and titration rate should be guided by clinical response.
Topamax is available in film-coated tablets and a hard capsule formulation. It is recommended that film-coated tablets not be broken. The hard capsule formulation is provided for those patients who cannot swallow tablets, e.g., paediatric and the elderly.
Topamax hard capsules may be swallowed whole or may be administered by carefully opening the capsule and sprinkling the entire contents on a small amount (teaspoon) of soft food. This medicinal product/food mixture is to be swallowed immediately and not chewed. It must not be stored for future use.
It is not necessary to monitor topiramate plasma concentrations to optimize therapy with Topamax. On rare occasions, the addition of topiramate to phenytoin may require an adjustment of the dose of phenytoin to achieve optimal clinical outcome. Addition or withdrawal of phenytoin and carbamazepine to adjunctive therapy with Topamax may require adjustment of the dose of Topamax.
Topamax can be taken without regard to meals.
In patients with or without a history of seizures or epilepsy, antiepileptic drugs including topiramate should be gradually withdrawn to minimize the potential for seizures or increased seizure frequency. In clinical trials, daily dosages were decreased in weekly intervals by 50-100 mg in adults with epilepsy and by 25-50 mg in adults receiving topiramate at doses up to 100 mg/day for migraine prophylaxis. In paediatric clinical trials, topiramate was gradually withdrawn over a 2-8 week period.
Monotherapy epilepsy
General
When concomitant antiepileptic drugs (AEDs) are withdrawn to achieve monotherapy with topiramate, consideration should be given to the effects this may have on seizure control. Unless safety concerns require an abrupt withdrawal of the concomitant AED, a gradual discontinuation at the rate of approximately one-third of the concomitant AED dose every 2 weeks is recommended.
When enzyme inducing medicinal products are withdrawn, topiramate levels will increase. A decrease in Topamax (topiramate) dosage may be required if clinically indicated.
Adults
Dose and titration should be guided by clinical response. Titration should begin at 25 mg nightly for 1 week. The dosage should then be increased at 1- or 2-week intervals by increments of 25 or 50 mg/day, administered in two divided doses. If the patient is unable to tolerate the titration regimen, smaller increments or longer intervals between increments can be used.
The recommended initial target dose for topiramate monotherapy in adults is 100 mg/day to 200 mg/day in 2 divided doses. The maximum recommended daily dose is 500 mg/day in 2 divided doses. Some patients with refractory forms of epilepsy have tolerated topiramate monotherapy at doses of 1,000 mg/day. These dosing recommendations apply to all adults including the elderly in the absence of underlying renal disease.
Paediatric population (children over 6 years of age)
Dose and titration rate in children should be guided by clinical outcome. Treatment of children over 6 years of age should begin at 0.5 to 1 mg/kg nightly for the first week. The dosage should then be increased at 1 or 2 week intervals by increments of 0.5 to 1 mg/kg/day, administered in two divided doses. If the child is unable to tolerate the titration regimen, smaller increments or longer intervals between dose increments can be used.
The recommended initial target dose range for topiramate monotherapy in children over 6 years of age is 100 mg/day depending on clinical response (this is about 2.0mg/kg/day in children 6-16 years).
Adjunctive therapy epilepsy (partial onset seizures with or without secondary generalization, primary generalized tonic-clonic seizures, or seizures associated with Lennox-Gastaut syndrome)
Adults
Therapy should begin at 25-50 mg nightly for one week. Use of lower initial doses has been reported, but has not been studied systematically. Subsequently, at weekly or bi-weekly intervals, the dose should be increased by 25-50 mg/day and taken in two divided doses. Some patients may achieve efficacy with once-a-day dosing.
In clinical trials as adjunctive therapy, 200 mg was the lowest effective dose. The usual daily dose is 200-400 mg in two divided doses.
These dosing recommendations apply to all adults, including the elderly, in the absence of underlying renal disease (see section 4.4).
Paediatric population (children aged 2 years and above)
The recommended total daily dose of Topamax (topiramate) as adjunctive therapy is approximately 5 to 9 mg/kg/day in two divided doses. Titration should begin at 25 mg (or less, based on a range of 1 to 3 mg/kg/day) nightly for the first week. The dosage should then be increased at 1- or 2-week intervals by increments of 1 to 3 mg/kg/day (administered in two divided doses) to achieve optimal clinical response.
Daily doses up to 30 mg/kg/day have been studied and were generally well tolerated.
Migraine
Adults
The recommended total daily dose of topiramate for prophylaxis of migraine headache is 100 mg/day administered in two divided doses. Titration should begin at 25 mg nightly for 1 week. The dosage should then be increased in increments of 25 mg/day administered at 1-week intervals. If the patient is unable to tolerate the titration regimen, longer intervals between dose adjustments can be used.
Some patients may experience a benefit at a total daily dose of 50 mg/day. Patients have received a total daily dose up to 200 mg/day. This dose may be benefit in some patients, nevertheless, caution is advised due to an increase incidence of side effects.
Paediatric population
Topamax (topiramate) is not recommended for treatment or prevention of migraine in children due to insufficient data on safety and efficacy.
General dosing recommendations for Topamax in special patient populations
Renal impairment
In patients with impaired renal function (CLCR
In patients with end-stage renal failure, since topiramate is removed from plasma by haemodialysis, a supplemental dose of Topamax equal to approximately one-half the daily dose should be administered on haemodialysis days. The supplemental dose should be administered in divided doses at the beginning and completion of the haemodialysis procedure. The supplemental dose may differ based on the characteristics of the dialysis equipment being used (see section 5.2)..
Hepatic impairment
In patients with moderate to severe hepatic impairment topiramate should be administered with caution as the clearance of topiramate is decreased.
Elderly
No dose adjustment is required in the elderly population providing renal function is intact.
4.3 Contraindications
Hypersensitivity to the active substance or to any of the excipients.
Migraine prophylaxis in pregnancy and in women of childbearing potential if not using effective methods of contraception.
4.4 Special Warnings And Precautions For Use
In situations where rapid withdrawal of topiramate is medically required, appropriate monitoring is recommended (see section 4.2 for further details).
As with other antiepileptic drugs, some patients may experience an increase in seizure frequency or the onset of new types of seizures with topiramate. These phenomena may be the consequence of an overdose, a decrease in plasma concentrations of concomitantly used antiepileptics, progress of the disease or a paradoxical effect.
Adequate hydration while using topiramate is very important. Hydration can reduce the risk of nephrolithiasis (see below). Proper hydration prior to and during activities such as exercise or exposure to warm temperatures may reduce the risk of heat-related adverse reactions (see section 4.8).
Mood disturbances/depression
An increased incidence of mood disturbances and depression has been observed during topiramate treatment.
Suicide/suicide ideation
Suicidal ideation and behaviour have been reported in patients treated with antiepileptic agents in several indications. A meta-analysis of randomised placebo-controlled trials of antiepileptic drugs has shown a small increased risk of suicidal ideation and behaviour. The mechanism of this risk is not known and the available data do not exclude the possibility of an increased risk for topiramate.
In double blind clinical trials, suicide related events (SREs) (suicidal ideation, suicide attempts and suicide) occurred at a frequency of 0.5% in topiramate treated patients (46 out of 8,652 patients treated) and at a nearly 3-fold higher incidence than those treated with placebo (0.2%; 8 out of 4,045 patients treated).
Patients therefore should be monitored for signs of suicidal ideation and behaviour and appropriate treatment should be considered. Patients (and caregivers of patients) should be advised to seek medical advice should signs of suicidal ideation or behaviour emerge.
Nephrolithiasis
Some patients, especially those with a predisposition to nephrolithiasis, may be at increased risk for renal stone formation and associated signs and symptoms such as renal colic, renal pain or flank pain.
Risk factors for nephrolithiasis include prior stone formation, a family history of nephrolithiasis and hypercalciuria. None of these risk factors can reliably predict stone formation during topiramate treatment. In addition, patients taking other medicinal products associated with nephrolithiasis may be at increased risk.
Decreased hepatic function
In hepatically-impaired patients, topiramate should be administered with caution as the clearance of topiramate may be decreased.
Acute myopia and secondary angle closure glaucoma
A syndrome consisting of acute myopia associated with secondary angle closure glaucoma has been reported in patients receiving topiramate. Symptoms include acute onset of decreased visual acuity and/or ocular pain. Ophthalmologic findings can include myopia, anterior chamber shallowing, ocular hyperaemia (redness) and increased intraocular pressure. Mydriasis may or may not be present. This syndrome may be associated with supraciliary effusion resulting in anterior displacement of the lens and iris, with secondary angle closure glaucoma. Symptoms typically occur within 1 month of initiating topiramate therapy. In contrast to primary narrow angle glaucoma, which is rare under 40 years of age, secondary angle closure glaucoma associated with topiramate has been reported in paediatric patients as well as adults. Treatment includes discontinuation of topiramate, as rapidly as possible in the judgment of the treating physician, and appropriate measures to reduce intraocular pressure. These measures generally result in a decrease in intraocular pressure.
Elevated intraocular pressure of any aetiology, if left untreated, can lead to serious sequelae including permanent vision loss.
A determination should be made whether patients with history of eye disorders should be treated with topiramate.
Metabolic acidosis
Hyperchloremic, non-anion gap, metabolic acidosis (i.e. decreased serum bicarbonate below the normal reference range in the absence of respiratory alkalosis) is associated with topiramate treatment. This decrease in serum bicarbonate is due to the inhibitory effect of topiramate on renal carbonic anhydrase. Generally, the decrease in bicarbonate occurs early in treatment although it can occur at any time during treatment. These decreases are usually mild to moderate (average decrease of 4 mmol/l at doses of 100 mg/day or above in adults and at approximately 6 mg/kg/day in paediatric patients). Rarely, patients have experienced decreases to values below 10 mmol/l. Conditions or therapies that predispose to acidosis (such as renal disease, severe respiratory disorders, status epilepticus, diarrhoea, surgery, ketogenic diet or certain medicinal products) may be additive to the bicarbonate lowering effects of topiramate.
Chronic metabolic acidosis increases the risk of renal stone formation and may potentially lead to osteopenia.
Chronic metabolic acidosis in paediatric patients can reduce growth rates. The effect of topiramate on bone-related sequelae has not been systematically investigated in paediatric or adult populations.
Depending on underlying conditions, appropriate evaluation including serum bicarbonate levels is recommended with topiramate therapy. If metabolic acidosis develops and persists, consideration should be given to reducing the dose or discontinuing topiramate (using dose tapering).
Topiramate should be used with caution in patients with conditions or treatments that represent a risk factor for the appearance of metabolic acidosis.
Nutritional supplementation
Some patients may experience weight loss whilst on treatment with topiramate. It is recommended that patients on topiramate treatment should be monitored for weight loss. A dietary supplement or increased food intake may be considered if the patient is losing weight while on topiramate.
Lactose intolerance
Topamax tablets contain lactose. Patients with rare hereditary problems of galactose intolerance, Lapp lactase deficiency or glucose-galactose malabsorption should not take this medication.
Sucrose intolerance
Topamax capsules contain sucrose. Patients with rare hereditary problems of fructose intolerance, glucose-galactose malabsorption or sucrase-isomaltase insufficiency should not take this medicine.
4.5 Interaction With Other Medicinal Products And Other Forms Of Interaction
Effects of Topamax on other antiepileptic medicinal products
The addition of Topamax to other antiepileptic drugs (phenytoin, carbamazepine, valproic acid, phenobarbital, primidone) has no effect on their steady-state plasma concentrations, except in the occasional patient, where the addition of Topamax to phenytoin may result in an increase of plasma concentrations of phenytoin. This is possibly due to inhibition of a specific enzyme polymorphic isoform (CYP2C19). Consequently, any patient on phenytoin showing clinical signs or symptoms of toxicity should have phenytoin levels monitored.
A pharmacokinetic interaction study of patients with epilepsy indicated the addition of topiramate to lamotrigine had no effect on steady state plasma concentration of lamotrigine at topiramate doses of 100 to 400 mg/day. In addition, there was no change in steady state plasma concentration of topiramate during or after removal of lamotrigine treatment (mean dose of 327 mg/day).
Topiramate inhibits the enzyme CYP 2C19 and may interfere with other substances metabolized via this enzyme (e.g., diazepam, imipramin, moclobemide, proguanil, omeprazol).
Effects of other antiepileptic medicinal products on Topamax
Phenytoin and carbamazepine decrease the plasma concentration of topimarate. The addition or withdrawal of phenytoin or carbamazepine to Topamax therapy may require an adjustment in dosage of the latter. This should be done by titrating to clinical effect. The addition or withdrawal of valproic acid does not produce clinically significant changes in plasma concentrations of Topamax and, therefore, does not warrant dosage adjustment of Topamax. The results of these interactions are summarized below:
AED Coadministered
|
AED Concentration
|
Topamax Concentration
|
Phenytoin
|
↔**
|
|
Carbamazepine (CBZ)
|
↔
|
|
Valproic acid
|
↔
|
↔
|
Lamotrigine
|
↔
|
↔
|
Phenobarbital
|
↔
|
NS
|
Primidone
|
↔
|
NS
|
↔ = No effect on plasma concentration (
** = Plasma concentrations increase in individual patients
NS = Not studied
AED = antiepileptic drug
|
|
|
Other medicinal product interactions
Digoxin
In a single-dose study, serum digoxin area under plasma concentration curve (AUC) decreased 12% due to concomitant administration of Topamax. The clinical relevance of this observation has not been established. When Topamax is added or withdrawn in patients on digoxin therapy, careful attention should be given to the routine monitoring of serum digoxin.
CNS depressants
Concomitant administration of Topamax and alcohol or other CNS depressant medicinal products has not been evaluated in clinical studies. It is recommended that Topamax not be used concomitantly with alcohol or other CNS depressant medicinal products.
St John's Wort (Hypericum perforatum)
A risk of decreased plasma concentrations resulting in a loss of efficacy could be observed with co-administration of topiramate and St John's Wort. There have been no clinical studies evaluating this potential interaction.
Oral contraceptives
In a pharmacokinetic interaction study in healthy volunteers with a concomitantly administered combination oral contraceptive product containing 1 mg norethindrone (NET) plus 35 µg ethinyl estradiol (EE), Topamax given in the absence of other medications at doses of 50 to 200 mg/day was not associated with statistically significant changes in mean exposure (AUC) to either component of the oral contraceptive. In another study, exposure to EE was statistically significantly decreased at doses of 200, 400, and 800 mg/day (18%, 21%, and 30%, respectively) when given as adjunctive therapy in epilepsy patients taking valproic acid. In both studies, Topamax (50-200 mg/day in healthy volunteers and 200-800 mg/day in epilepsy patients) did not significantly affect exposure to NET. Although there was a dose dependent decrease in EE exposure for doses between 200-800 mg/day (in epilepsy patients), there was no significant dose dependent change in EE exposure for doses of 50-200 mg/day (in healthy volunteers). The clinical significance of the changes observed is not known. The possibility of decreased contraceptive efficacy and increased breakthrough bleeding should be considered in patients taking combination oral contraceptive products with Topamax. Patients taking estrogen containing contraceptives should be asked to report any change in their bleeding patterns. Contraceptive efficacy can be decreased even in the absence of breakthrough bleeding.
Lithium
In healthy volunteers, there was an observed reduction (18% for AUC) in systemic exposure for lithium during concomitant administration with topiramate 200 mg/day. In patients with bipolar disorder, the pharmacokinetics of lithium were unaffected during treatment with topiramate at doses of 200 mg/day; however, there was an observed increase in systemic exposure (26% for AUC) following topiramate doses of up to 600 mg/day. Lithium levels should be monitored when co-administered with topiramate.
Risperidone
Drug-drug interaction studies conducted under single dose conditions in healthy volunteers and multiple dose conditions in patients with bipolar disorder, yielded similar results. When administered concomitantly with topiramate at escalating doses of 100, 250 and 400 mg/day there was a reduction in risperidone (administered at doses ranging from 1 to 6 mg/day) systemic exposure (16% and 33% for steady-state AUC at the 250 and 400 mg/day doses, respectively). However, differences in AUC for the total active moiety between treatment with risperidone alone and combination treatment with topiramate were not statistically significant. Minimal alterations in the pharmacokinetics of the total active moiety (risperidone plus 9-hydroxyrisperidone) and no alterations for 9-hydroxyrisperidone were observed. There were no significant changes in the systemic exposure of the risperidone total active moiety or of topiramate. When topiramate was added to existing risperidone (1-6 mg/day) treatment, adverse events were reported more frequently than prior to topiramate (250-400 mg/day) introduction (90% and 54 % respectively). The most frequently reported AE's when topiramate was added to risperidone treatment were: somnolence (27% and 12%), paraesthesia (22% and 0%) and nausea (18% and 9% respectively).
Hydrochlorothiazide (HCTZ)
A drug-drug interaction study conducted in healthy volunteers evaluated the steady-state pharmacokinetics of HCTZ (25 mg q24h) and topiramate (96 mg q12h) when administered alone and concomitantly. The results of this study indicate that topiramate Cmax increased by 27% and AUC increased by 29% when HCTZ was added to topiramate. The clinical significance of this change is unknown. The addition of HCTZ to topiramate therapy may require an adjustment of the topiramate dose. The steady-state pharmacokinetics of HCTZ were not significantly influenced by the concomitant administration of topiramate. Clinical laboratory results indicated decreases in serum potassium after topiramate or HCTZ administration, which were greater when HCTZ and topiramate were administered in combination.
Metformin
A drug-drug interaction study conducted in healthy volunteers evaluated the steady-state pharmacokinetics of metformin and topiramate in plasma when metformin was given alone and when metformin and topiramate were given simultaneously. The results of this study indicated that metformin mean Cmax and mean AUC0-12h increased by 18% and 25%, respectively, while mean CL/F decreased 20% when metformin was co-administered with topiramate. Topiramate did not affect metformin tmax. The clinical significance of the effect of topiramate on metformin pharmacokinetics is unclear. Oral plasma clearance of topiramate appears to be reduced when administered with metformin. The extent of change in the clearance is unknown. The clinical significance of the effect of metformin on topiramate pharmacokinetics is unclear.
When Topamax is added or withdrawn in patients on metformin therapy, careful attention should be given to the routine monitoring for adequate control of their diabetic disease state.
Pioglitazone
A drug-drug interaction study conducted in healthy volunteers evaluated the steady-state pharmacokinetics of topiramate and pioglitazone when administered alone and concomitantly. A 15% decrease in the AUC,ss of pioglitazone with no alteration in Cmax,ss was observed. This finding was not statistically significant. In addition, a 13% and 16% decrease in Cmax,ss and AUC,ss respectively, of the active hydroxy-metabolite was noted as well as a 60% decrease in Cmax,ss and AUC,ss of the active keto-metabolite. The clinical significance of these findings is not known. When Topamax is added to pioglitazone therapy or pioglitazone is added to Topamax therapy, careful attention should be given to the routine monitoring of patients for adequate control of their diabetic disease state.
Glyburide
A drug-drug interaction study conducted in patients with type 2 diabetes evaluated the steady-state pharmacokinetics of glyburide (5 mg/day) alone and concomitantly with topiramate (150 mg/day). There was a 25% reduction in glyburide AUC24 during topiramate administration. Systemic exposure of the active metabolites, 4-trans-hydroxy-glyburide (M1) and 3-cis-hydroxyglyburide (M2), were also reduced by 13% and 15%, respectively. The steady-state pharmacokinetics of topiramate were unaffected by concomitant administration of glyburide.
When topiramate is added to glyburide therapy or glyburide is added to topiramate therapy, careful attention should be given to the routine monitoring of patients for adequate control of their diabetic disease state.
Other forms of interactions
Agents predisposing to nephrolithiasis
Topamax, when used concomitantly with other agents predisposing to nephrolithiasis, may increase the risk of nephrolithiasis. While using Topamax, agents like these should be avoided since they may create a physiological environment that increases the risk of renal stone formation.
Valproic acid
Concomitant administration of topiramate and valproic acid has been associated with hyperammonemia with or without encephalopathy in patients who have tolerated either medicinal product alone. In most cases, symptoms and signs abated with discontinuation of either medicinal product. This adverse reaction is not due to a pharmacokinetic interaction. An association of hyperammonemia with topiramate monotherapy or concomitant treatment with other antiepileptics has not been established.
Additional pharmacokinetic drug interaction studies
Clinical studies have been conducted to assess the potential pharmacokinetic drug interaction between topiramate and other agents. The changes in Cmax or AUC as a result of the interactions are summarized below. The second column (concomitant drug concentration) describes what happens to the concentration of the concomitant drug listed in the first column when topiramate is added. The third column (topiramate concentration) describes how the coadministration of a drug listed in the first column modifies the concentration of topiramate.
Summary of Results from Additional Clinical Pharmacokinetic Drug Interaction Studies
|
|
|
Concomitant Drug
|
Concomitant Drug Concentrationa
|
Topiramate Concentrationa
|
Amitriptyline
|
↔ 20% increase in Cmax and AUC of nortriptyline metabolite
|
NS
|
Dihydroergotamine (Oral and Subcutaneous)
|
↔
|
↔
|
Haloperidol
|
↔ 31% increase in AUC of the reduced metabolite
|
NS
|
Propranolol
|
↔ 17% increase in Cmax for 4-OH propranolol (TPM 50 mg q12h)
|
9% and 16% increase in Cmax,
9% and17% increase in AUC (40 and 80 mg propranolol q12h respectively)
|
Sumatriptan (Oral and Subcutaneous)
|
↔
|
NS
|
Pizotifen
|
↔
|
↔
|
Diltiazem
|
25% decrease in AUC of diltiazem and 18% decrease in DEA, and ↔ for DEM*
|
20% increase in AUC
|
Venlafaxine
|
↔
|
↔
|
Flunarizine
|
16% increase in AUC
(TPM 50 mg q12h)b
|
↔
|
a % values are the changes in treatment mean Cmax or AUC with respect to monotherapy
↔ = No effect on Cmax and AUC (
NS = Not studied
* DEA = des acetyl diltiazem, DEM = N-demethyl diltiazem
b Flunarizine AUC increased 14% in subjects taking flunarizine alone. Increase in exposure may be attributed to accumulation during achievement of steady state.
|
|
|
4.6 Pregnancy And Lactation
Topiramate was teratogenic in mice, rats and rabbits. In rats, topiramate crosses the placental barrier.
Data from the U.K. pregnancy register and the North American Antiepileptic Drug (NAAED) pregnancy registry indicate that infants exposed to topiramate monotherapy in the first trimester have an increased risk of congenital malformations (e.g., craniofacial defects, such as cleft lip/palate, hypospadias, and anomalies involving various body systems).
The NAAED pregnancy registry data for topiramate monotherapy showed an approximate 3-fold higher incidence of major congenital malformations, compared with a reference group not taking antiepileptic drugs. Furthermore, there was , a higher prevalence of low birth weight (<2500 grams) following topiramate treatment than in the reference group..
In addition, data from these registries and other studies indicate that, compared with monotherapy, there is an increased risk of teratogenic effects associated with the use of antiepileptic drugs in combination therapy.
It is recommended that women of child bearing potential use adequate contraception and consider alternative therapeutic options.
Animal studies have shown excretion of topiramate in milk. The excretion of topiramate in human milk has not been evaluated in controlled studies. Limited observations in patients suggest an extensive excretion of topiramate into breast milk. Since many medicinal products are excreted into human milk, a decision must be made whether to suspend breast-feeding or to discontinue/ abstain from topiramate therapy taking into account the importance of the medicinal product to the mother (section 4.4).
Indication Epilepsy
During pregnancy, topiramate should be prescribed after fully informing the woman of the known risks of uncontrolled epilepsy to the pregnancy and the potential risks of the medicinal product to the foetus.
Indication Migraine Prophylaxis
Topiramate is contraindicated in pregnancy, and in women of childbearing potential if an effective method of contraception is not used (see sections 4.3 and 4.5).
4.7 Effects On Ability To Drive And Use Machines
Topamax has minor or moderate influence on the ability to drive and use machines. Topiramate acts on the central nervous system and may produce drowsiness, dizziness or other related symptoms. It may also cause visual disturbances and/or blurred vision. These adverse reactions could potentially be dangerous in patients driving a vehicle or operating machinery, particularly until such time as the individual patient's experience with the medicinal products established.
No studies on the effects on the ability to drive and use machines have been performed.
4.8 Undesirable Effects
The safety of topiramate was evaluated from a clinical trial database consisting of 4,111 patients (3,182 on topiramate and 929 on placebo) who participated in 20 double-blind trials and 2,847 patients who participated in 34 open-label trials, respectively, for topiramate as adjunctive treatment of primary generalized tonic-clonic seizures, partial onset seizures, seizures associated with Lennox-Gastaut syndrome, monotherapy for newly or recently diagnosed epilepsy or migraine prophylaxis. The majority of ADRs were mild to moderate in severity. ADRs identified in clinical trials, and during post-marketing experience (as indicated by “*”) are listed by their incidence in clinical trials in Table 1. Assigned frequencies are as follows:
Very common
|
|
Common
|
|
Uncommon
|
|
Rare
|
|
Not known
|
cannot be estimated from the available data
|
The most common ADRs (those with an incidence of >5% and greater than that observed in placebo in at least 1 indication in double-blind controlled studies with topiramate) include: anorexia, decreased appetite, bradyphrenia, depression, expressive language disorder, insomnia, coordination abnormal, disturbance in attention, dizziness, dysarthria, dysgeusia, hypoesthesia, lethargy, memory impairment, nystagmus, paresthesia, somnolence, tremor, diplopia, vision blurred, diarrhoea, nausea, fatigue, irritability, and weight decreased.
Paediatric population
ADRs reported more frequently (
ADRs that were reported in children but not in adults in double-blind controlled studies include: eosinophilia, psychomotor hyperactivity, vertigo, vomiting, hyperthermia, pyrexia and learning disability.
Table 1: Topiramate Adverse Drug Reactions
|
|
|
|
|
|
System Organ Class
|
Very common
|
Common
|
Uncommon
|
Rare
|
Not known
|
Infections and infestations
|
Nasopharyngitis*
|
|
|
|
|
Blood and lymphatic system disorders
|
|
Anaemia
|
Leucopenia, thrombocytopenia lymphadenopathy, eosinophilia
|
Neutropenia*
|
|
Immune system disorders
|
|
Hypersensitivity
|
|
|
Allergic oedema*, conjunctival oedema*
|
Metabolism and nutrition disorders
|
|
Anorexia, decreased appetite
|
Metabolic acidosis, Hypokalaemia, increased appetite, polydipsia
|
Acidosis hyperchloraemic
|
|
Psychiatric disorders
|
Depression
|
Bradyphrenia, insomnia, expressive language disorder, anxiety, confusional state, disorientation, aggression, mood altered, agitation, mood swings, depressed mood, anger, abnormal behaviour
|
Suicidal ideation, suicide attempt, hallucination, psychotic disorder, hallucination auditory, hallucination visual, apathy, lack of spontaneous speech, sleep disorder, affect lability, libido decreased, restlessness, crying, dysphemia, euphoric mood, paranoia, perseveration, panic attack, tearfulness, reading disorder, initial insomnia, flat affect, thinking abnormal, loss of libido, listless, middle insomnia, distractibility, early morning awakening, panic reaction, elevated mood
|
Mania, panic disorder, feeling of despair*, hypomania
|
|
Nervous system disorders
|
Paraesthesia, somnolence Dizziness
|
Disturbance in attention, memory impairment, amnesia, cognitive disorder, mental impairment, psychomotor skills impaired, convulsion, coordination abnormal, tremor, lethargy, hypoaesthesia, nystagmus, dysgeusia, balance disorder, dysarthria, intention tremor, sedation ,
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Depressed level of consciousness, grand mal convulsion, visual field defect, complex partial seizures, speech disorder, psychomotor hyperactivity, syncope, sensory disturbance, drooling, hypersomnia, aphasia, repetitive speech, hypokinesia, dyskinesia, dizziness postural, poor quality sleep, burning sensation, sensory loss, parosmia, cerebellar syndrome, dysaesthesia, hypogeusia, stupor, clumsiness, aura, ageusia, dysgraphia, dysphasia, neuropathy peripheral, presyncope, dystonia, formication
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Apraxia, circadian rhythm sleep disorder, hyperaesthesia, hyposmia, anosmia, essential tremor, akinesia, unresponsive to stimuli
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Eye disorders
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Vision blurred, diplopia, visual disturbance
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