Oral Partial seizures with or without secondary generalised tonic-clonic seizures, Primary generalised tonic-clonic seizures
Adult: As monotherapy: Initially, 25 mg at night for 1 week, then increased in increments of 25 mg or 50 mg at 1- to 2-week intervals until an effective dose is reached. Doses and titration rates must be guided by clinical response. Usual dose: 100-200 mg daily. Max: 500 mg daily; doses of 1,000 mg daily have been used in refractory cases. As adjunctive therapy: Initially, 25-50 mg at night for 1 week, then increased in increments of 25 mg or 50 mg at 1- to 2-week intervals until an effective dose is reached. Usual dose: 200-400 mg daily. Usual daily doses may be taken as a single dose or in 2 divided doses depending on the formulation. Dosage recommendations may vary among individual products and between countries (refer to specific product guidelines). Child: ≥6 years As monotherapy: Initially, 0.5-1 mg/kg at night for 1 week, then increased in increments of 0.5-1 mg/kg daily at 1- to 2-week intervals until an effective dose is reached. Initial target dose: 100 mg (approx 2 mg/kg) daily in 2 divided doses. ≥2 years As adjunctive therapy: Initially, 25 mg (or less, based on a range of 1-3 mg/kg daily) at night for 1 week, then increased in increments of 1-3 mg/kg daily at 1- to 2-week intervals until an effective dose is reached. Usual dose: Approx 5-9 mg/kg daily, may be increased up to 30 mg/kg daily. Doses and titration rates must be guided by clinical response. Treatment and dosage recommendations may vary among individual products and between countries (refer to specific product guidelines).
Oral Prophylaxis of migraine
Adult: Initially, 25 mg at night for 1 week, then increased in increments of 25 mg daily at weekly intervals until an effective dose is reached. Dose and titration rate must be guided by clinical response. Usual dose: 100 mg daily, may be increased to 200 mg daily if necessary. Usual daily doses may be taken as a single dose or in 2 divided doses depending on the formulation (refer to specific product guidelines).
Oral Adjunct for seizures associated with Lennox-Gastaut syndrome
Adult: Initially, 25-50 mg at night for 1 week, then increased in increments of 25 mg or 50 mg at 1- to 2-week intervals until an effective dose is reached. Dose and titration rate must be guided by clinical response. Usual dose: 200-400 mg daily. Usual daily doses may be taken as a single dose or in 2 divided doses depending on the formulation (refer to specific product guidelines). Child: ≥2 years Initially, 25 mg (or less, based on a range of 1-3 mg/kg daily) at night for 1 week, then increased in increments of 1-3 mg/kg daily at 1- to 2-week intervals until an effective dose is reached. Dose and titration rate must be guided by clinical response. Usual dose: Approx 5-9 mg/kg daily, may be increased up to 30 mg/kg daily. Usual daily doses may be taken as a single dose or in 2 divided doses depending on the formulation (refer to specific product guidelines).
Suy thận
Patient undergoing haemodialysis: Supplemental dose equal to 50% of the daily dose, given in divided doses (at the start and upon completion of haemodialysis). Dose may differ based on the dialysis equipment being used.
CrCl (mL/min)
Dosage
≤70
Reduce to 50% of the usual starting and maintenance dose; titrate more slowly.
Cách dùng
May be taken with or without food.
Chống chỉ định
Migraine prophylaxis: Pregnancy and in women of childbearing potential who are not using effective contraception.
Thận trọng
Patient with predisposition to nephrolithiasis (e.g. prior stone formation, family history of nephrolithiasis, hypercalciuria), history of eye disorders, predisposition to acidosis (e.g. severe respiratory disorders, diarrhoea, status epilepticus, surgery, ketogenic diet, use of certain medicinal products). Avoid abrupt withdrawal. Renal and hepatic impairment. Children. Pregnancy (for epilepsy) and lactation.
Tác dụng không mong muốn
Significant: Increased seizure frequency or onset of new types of seizures; oligohidrosis, hyperthermia (particularly in young children exposed to high temperature); cognitive-related dysfunction (e.g. confusion, psychomotor slowing, difficulty with concentration or attention, speech or language problems, difficulty with memory), mood disturbances, depression, suicidal ideation and behaviour; serious skin reactions (e.g. Stevens-Johnson syndrome, toxic epidermal necrolysis), nephrolithiasis, acute myopia associated with secondary angle-closure glaucoma, visual field defects; hyperchloraemic metabolic acidosis (non-anion gap), hyperammonaemia with or without encephalopathy, weight loss. Blood and lymphatic system disorders: Anaemia. Ear and labyrinth disorders: Ear pain, vertigo, tinnitus. Eye disorders: Blurred vision, nystagmus, diplopia. Gastrointestinal disorders: Nausea, diarrhoea, constipation, vomiting, upper abdominal pain, dysgeusia, dry mouth, stomach or abdominal discomfort, gastritis, oral paraesthesia. General disorders and administration site conditions: Fatigue, malaise, asthenia, pyrexia, gait disturbance, feeling abnormal. Immune system disorders: Hypersensitivity. Investigations: Increased weight; decreased BMD (in children). Metabolism and nutrition disorders: Anorexia, decreased appetite. Musculoskeletal and connective tissue disorders: Arthralgia, myalgia, muscle spasms or twitching, muscular weakness, musculoskeletal chest pain. Nervous system disorders: Dizziness, somnolence, paraesthesia, amnesia, abnormal coordination, tremor or intention tremor, lethargy, hypoaesthesia, balance disorder, dysarthria, sedation. Psychiatric disorders: Insomnia, bradyphrenia, anxiety, disorientation, aggression, anger, abnormal behaviour, irritability. Renal and urinary disorders: Dysuria, nephrocalcinosis, pollakiuria. Respiratory, thoracic and mediastinal disorders: Nasopharyngitis, dyspnoea, nasal congestion, cough, epistaxis, rhinorrhoea. Skin and subcutaneous tissue disorders: Rash, pruritus, alopecia.
PO: Z (Congenital malformations and neurodevelopmental adverse effects have been reported. Consult prescribing or clinical guidelines for specific recommendations according to indications.)
Thông tin tư vấn bệnh nhân
This drug may cause drowsiness, dizziness or blurred vision, if affected, do not drive or operate machinery. Women of childbearing potential (who are being treated for epilepsy) must use highly effective birth control methods during treatment. Ensure proper hydration while on therapy, and prior to or during activities such as exercise or exposure to warm weather.
Chỉ số theo dõi
Perform pregnancy tests on women of childbearing potential before initiating treatment. Obtain electrolytes (including serum bicarbonate levels at baseline and during treatment), serum creatinine, and ammonia levels (if with altered mental status). Assess therapeutic efficacy (seizure activity, type, duration) at the start and throughout therapy. Monitor for weight loss, visual changes or disturbances, growth (height and weight) of children, signs and symptoms of oligohidrosis and hyperthermia (particularly in hot weather). Observe for the emergence or worsening of depression, suicidal ideation or behaviour, and/or any unusual changes in mood or behaviour. Evaluate eating and weight behaviours in patients with eating disorder symptoms or predisposition.
Quá liều
Symptoms: Convulsions, drowsiness, blurred vision, diplopia, dizziness, abdominal pain, speech disturbances, impaired mentation, lethargy, abnormal coordination, stupor, hypotension, agitation, depression, and severe metabolic acidosis. Management: Supportive treatment. Ensure patient is well hydrated. Consider performing haemodialysis.
Tương tác
Decreased plasma concentration with phenytoin and carbamazepine. May increase the plasma concentrations of lithium, metformin, amitriptyline, and phenytoin. Reduces the plasma concentration of digoxin, pioglitazone, and glibenclamide. May reduce the efficacy of combined oral contraceptives, increasing the risk of breakthrough bleeding. Increased plasma concentration with hydrochlorothiazide. Concomitant use with valproic acid may lead to hypothermia and hyperammonaemia with or without encephalopathy. Decreased prothrombin time/INR with warfarin. May increase the risk of oligohidrosis and hyperthermia with other carbonic anhydrase inhibitors and anticholinergic agents. Concomitant use with other carbonic anhydrase inhibitors (e.g. zonisamide, acetazolamide) may also increase the severity of metabolic acidosis and the risk of nephrolithiasis. May enhance the adverse or toxic effects of other CNS depressants.
Tương tác với thức ăn
May enhance the CNS depressant effect with alcohol.
Tác dụng
Description: Mechanism of Action: Topiramate is a sulfamate-substituted monosaccharide. The exact mechanism of action is unknown but may be due to blockade of neuronal voltage-dependent Na channels, augmentation of GABA activity at some subtypes of GABAA receptor, antagonism of α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA)/kainate subtype of glutamate receptor, and weak inhibition of carbonic anhydrase (particularly isozymes II and IV). Pharmacokinetics: Absorption: Rapidly and well absorbed. Bioavailability: Approx 80% (conventional form). Time to peak plasma concentration: 0.5 hours (oral solution); 2-3 hours (tab/conventional sprinkle cap). Distribution: Crosses the placenta and enters breast milk. Volume of distribution: 0.6-0.8 L/kg. Plasma protein binding: 15-41%. Metabolism: Not extensively metabolised; minor amounts are metabolised in the liver via hydroxylation, hydrolysis, and glucuronidation to form metabolites. Excretion: Via urine (approx 70% as unchanged drug). Elimination half-life: 21 hours.
Đặc tính
Topiramate Source: National Center for Biotechnology Information. PubChem Compound Summary for CID 5284627, Topiramate. https://pubchem.ncbi.nlm.nih.gov/compound/5284627. Accessed Aug. 25, 2022.
Bảo quản
Store between 15-30°C. Protect from moisture. Storage recommendations may vary between products. Refer to specific product guidelines.
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