Topiramate

A to Z Drug Facts

Topiramate

	Actions
	Indications
	Contraindications
	Route/Dosage
	Interactions
	Lab Test Interferences
	Adverse Reactions
	Precautions
Patient Care Considerations
	Administration/Storage
	Assessment/Interventions
	Patient/Family Education

(Toe-PEER-ah-mate)

Topamax

Tablets: 25 mg, 100 mg, 200 mg

Capsules, sprinkle: 15 mg, 25 mg

Class: Anticonvulsant

Actions Precise mechanism is unknown but topiramate may: block repetitively elicited action potentials; affect ability of chloride ion to move into neurosis; and antagonize an excitatory amino acid receptor.

Indications Adjunctive therapy for partial onset seizures; primary generalized tonic-clonic seizures; seizures associated with Lennox-Gastaut syndrome.

Contraindications Standard considerations.

Route/Dosage

ADULTS (³ 17 yr): PO 400 mg daily in 2 divided doses. Initiate therapy at 25 to 50 mg/day and titrate to an effective dose in increments of 25 to 50 mg/wk. Doses > 400 mg have not been shown to improve response.

CHILDREN (2 to 16 yr): PO 5 to 9 mg/kg/day in 2 divided doses. Initiate therapy at £ 25 mg (based on range of 1 to 3 mg/kg/day) nightly for first week and titrate to an effective dose at 1- to 2-wk intervals by increments of 1 to 3 mg/kg/day in 2 divided doses.

Interactions

Alcohol, CNS depressants: CNS depression and side effects may be increased. Carbamazepine: Effects of topiramate may be decreased. Carbonic anhydrase inhibitors (eg, acetazolamide): Increased risk of renal stone formation. Oral contraceptives: Efficacy of oral contraceptives may be decreased. Phenytoin: Effects of phenytoin may be increased while those of topiramate may decrease.

Lab Test Interferences None well documented.

Adverse Reactions

CARDIOVASCULAR: Palpitations. CNS: Memory, concentration, and attention difficulty; fatigue; confusion; somnolence; depression; ataxia; dizziness; psychomotor slowing; nervousness; speech disorder/problems; language problems; mood problems; aggressive behavior; apathy; emotional lability; paresthesia; tremor; depersonalization; malaise; hypokinesia; vertigo; stupor; grand mal convulsions; hyperkinesia; hypothesia; hypertonia; insomnia; hallucinations; euphoria; psychosis; decreased libido; suicide attempt; incoordination. DERMATOLOGIC: Rash; pruritis; acne; alopecia. EENT: Nystagmus; diplopia; abnormal vision; eye pain; decreased hearing; tinnitus; epistaxis; conjunctivitis. GI: Nausea; vomiting; flatulence; gastroenteritis; dyspepsia; anorexia; abdominal pain; constipation; diarrhea; gingivitis; taste perversion. GU: Breast pain; dysmenorrhea; menstrual disorder; hematuria; menorrhagia; leukorrhea; amenorrhea; intermenstrual bleeding; vaginitis; urinary tract infection; micturition frequency; urinary incontinence; dysuria; renal calculus; impotence. HEMATOLOGIC: Leukopenia; anemia. METABOLIC: Weight gain; weight loss. RESPIRATORY: Pharyngitis; sinusitis; dyspnea; coughing; bronchitis. OTHER: Asthenia; back, leg, and chest pain; flu-like symptoms; hot flushes; fever; arthralgia; myalgia; muscle weakness; body odor; edema; rigors.

Precautions

Pregnancy: Category C. Children: Safety and efficacy in children < 2 yr not established. Lactation: Undetermined. Elderly: No age-related differences in safety and efficacy have been seen, although consider age-related changes in renal function. Withdrawal: Gradually withdraw therapy to minimize potential of increased seizure frequency. Renal impairment: Reduce dose by 50% of Ccr < 70 mL/hr. Hemodialysis: Supplemental dose may be necessary before prolonged dialysis. Hepatic impairment: Administer with caution. Kidney stones: Risk of developing kidney stones may be increased. Acute myopia: Acute myopia secondary to angle closure glaucoma has been reported.

PATIENT CARE CONSIDERATIONS

Administration/Storage

Available only in tablet form for oral administration.
Store tablets at room temperature (59° to 86°F; 15° to 30°C).
Store in tightly closed container; protect from moisture.
May be taken with or without food.
Do not crush, chew, or break tablet because of bitter taste.

Assessment/Interventions

Obtain patient history, including drug history and any known allergies. Note hepatic, renal impairment.
Before initiation of therapy, assess the patient for hepatic or renal disorders, hypotension, alcohol abuse, or porphyria.
Assess type of seizure activity displayed, onset, and duration prior to the initiation of therapy.
Monitor patient during therapy for effectiveness and side effects. Report seizure activity and side effects to health care provider.

Patient/Family Education

Advise patient that medication may be taken with or without food.
Advise patient not to crush, break, or chew tablet.
Advise patient not to discontinue or change dose unless advised to do so by health care provider.
Advise patient that drug may cause drowsiness, dizziness, or blurred vision and to use caution while driving or performing other tasks requiring mental alertness until tolerance is determined.
Caution patient to consult with health care provider before using alcohol or taking any other drug, including otc medications.
Warn patient that stopping medication too quickly may precipitate seizures.
Advise patient regarding adequate fluid intake (2 to 3 L/day) to minimize renal stone development.
Warn patient not to stop taking other prescribed antiseizure medications; topiramate is used in conjunction with other medications.
Stress the need to take the medication exactly as prescribed and not to skip or double up on missed doses.
Advise patient to carry identification such as Medi-Alert that identifies medical condition and medication(s).
Advise patient to report any suspected side effects to health care provider.
Advise patient that effectiveness of oral contraceptives may be decreased and to consider use of an alternative method of contraception and to report any change in menstrual cycle.

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