pms-Topiramate

Monotherapy for the management of newly diagnosed epilepsy in adults & childn ≥6 yr. Adjunctive therapy for the management of epilepsy in adults & childn ≥2 yr who are not satisfactorily controlled w/ conventional therapy. Prophylaxis of migraine headache in adults.

Monotherapy for epilepsy Adult & childn ≥6 yr Initial target dose: 100 mg/day in 2 divided doses, may be increased at wkly intervals in increments of 50 mg/day. Max dose: 400 mg/day. Titration rate to 100 mg/day: 25 mg evening dose on wk 1; 25 mg morning dose & 25 mg evening dose on wk 2-3; 50 mg morning dose & 50 mg evening dose on wk 3-4. Adjunctive therapy for epilepsy Adult ≥17 yr Initiate at 50 mg/day in 2 divided doses, may be increased by 50 mg/day at wkly intervals. Maintenance dose: 200-400 mg/day in 2 divided doses. Max dose: 800 mg/day. Childn 2-16 yr Initiate at 25 mg (or less, based on a range of 1-3 mg/kg/day) nightly for the 1st wk, then increase at 1- or 2-wk intervals by increments of 1-3 mg/kg/day in 2 divided doses. Maintenance dose: Approx 5-9 mg/kg/day in 2 divided doses. Migraine prophylaxis Adult 100 mg/day in 2 divided doses. Titration rate to 100 mg/day: 25 mg evening dose on wk 1; 25 mg morning dose & 25 mg evening dose on wk 2; 25 mg morning dose & 50 mg evening dose on wk 3; 50 mg morning dose & 50 mg evening dose on wk 4.

May be taken with or without food: Do not break.

Hypersensitivity. Migraine prophylaxis: Women of childbearing potential not using effective contraception. Pregnancy.

Should not be used in the acute treatment of migraine attacks. Safety & efficacy have not been established in the management or prevention of cluster headache, hemiplegic, basilar, ophthalmoplegic, or transformed migraine headaches. Should be w/drawn gradually to minimize potential for seizures or increased seizure frequency. Risk of oligohidrosis, anhidrosis & hyperthermia; hyperchloremic, non-anion gap, metabolic acidosis; CNS-related adverse events eg, psychomotor slowing, difficulty w/ concentration & speech or language problems (particularly word-finding difficulties), somnolence or fatigue, & mood disturbances (including irritability & depression); paresthesia; acute myopia associated w/ secondary angle closure glaucoma; visual field defects; kidney stones. Measure baseline & periodic serum bicarbonate during treatment. Monitor for signs of suicidal ideation & behaviour. Topiramate alone or in concomitant treatment w/ valproic acid or other antiepileptic medications can cause hyperammonemia w/ or w/o encephalopathy. Hypothermia w/ concomitant valproic acid use. Caution when prescribed w/ other drugs that predispose patients to heat-related disorders eg, other carbonic anhydrase inhibitors & drugs w/ anticholinergic activity. Decreases in serum K w/ concomitant hydrochlorothiazide. Dietary supplement or increased food intake may be considered if patient is losing wt while on medication. Concomitant use w/ other carbonic anhydrase inhibitors may create a physiological environment that increases risk of kidney stone formation, & should therefore be avoided. Patients should not drive or operate machinery in case of somnolence, dizziness, confusion, difficulty concentrating, or visual effects. Caution in patients w/ hepatic impairment; patients w/ renal impairment or w/ ESRD receiving hemodialysis. Can cause fetal harm when administered to a pregnant woman. Discontinue breastfeeding or discontinue topiramate. Not indicated for any use in patients <2 yr. Not indicated for migraine prophylaxis in patients <18 yr. Limited information in patients >65 yr. Epilepsy: Should be used during pregnancy only if potential benefit outweighs potential risk. Newborns of mothers treated w/ topiramate should be monitored for metabolic acidosis. Consider benefits & risks of treatment when prescribing to women of childbearing potential.

Adult: Coordination problems, difficulty concentrating, slow thinking, confusion & forgetfulness, dizziness, tiredness, tingling, headache, URTI, drowsiness. Childn: Difficulty concentrating, forgetfulness, tiredness, drowsiness, nervousness, decreased appetite, wt loss, URTI, headache, fever, tingling, aggressive behaviour.

Decreased plasma conc w/ phenytoin, carbamazepine, valproic acid, lamotrigine. Decreased plasma conc of valproic acid. Risk of encephalopathy (w/ or w/o hyperammonemia) & hypothermia (w/ or w/o hyperammonemia) w/ valproic acid. May increase plasma conc of phenytoin. Decreased serum AUC of digoxin. Should not be used concomitantly w/ alcohol or other CNS depressants. Possibility of decreased contraceptive efficacy & increased breakthrough bleeding. Increased C_max & AUC w/ hydrochlorothiazide. Decreases in serum K w/ hydrochlorothiazide. Increased C_max & AUC of metformin. Reduced oral plasma clearance w/ metformin. Reduced systemic exposure of glyburide, lithium, risperidone, diltiazem. Decreased AUC of pioglitazone. Increased or decreased conc of amitriptyline. Decreased prothrombin time/INR responses following concomitant administration w/ vit K antagonist anticoagulants. May increase risk of nephrolithiasis when used concomitantly w/ other agents predisposing to nephrolithiasis eg, carbonic anhydrase inhibitors (eg, acetazolamide).

Anticonvulsants / Antimigraine Preparations

N03AX11 - topiramate ; Belongs to the class of other antiepileptics.

P₁S₁S₃