Sulthiame: clinical use

Prescribing considerations

• Restrict initiation and supervision to a paediatric neurologist experienced in epilepsy.
• Confirm the epilepsy syndrome and consider its favourable natural history and high spontaneous-remission rate.
• Avoid abrupt withdrawal.
• Use caution with renal impairment, psychiatric history and Leber hereditary optic neuropathy.

Contraindications and cautions

• Hypersensitivity to sulthiame, other sulphonamides, listed parabens or another formulation ingredient
• Hyperthyroidism
• Hypertension
• Known acute porphyria

Monitoring

• Check full blood count, liver enzymes and renal function before and during treatment.
• Stop and assess persistent creatinine elevation or clinically significant leucopenia or thrombocytopenia.
• Monitor mood, behaviour, cognition, vision and seizure pattern.
• Consider serum concentrations with phenytoin, lamotrigine, clobazam or other CYP2C19 substrates.
• Assess for metabolic acidosis, electrolyte disturbance and renal stones when clinically indicated.

Clinical pharmacology

Sulthiame is a membrane-permeant carbonic anhydrase inhibitor. It is rapidly absorbed orally, has relatively low protein binding and is eliminated mainly through the kidneys; elimination may be faster in children.

Formulation and product differences

• The selected licensed product is a white oral suspension supplied with an oral syringe and bottle adapter.
• Shake thoroughly before every measurement because the suspension sediments.
• It contains parabens, small quantities of sugars and sulphur dioxide, which may matter in allergy, bronchospasm or certain hereditary sugar-intolerance disorders.
• It can be given through a feeding tube followed by a water flush.

Oral suspension

Route: Oral

Strengths: 20 mg/mL