THERAPEUTICS

Brands

• Onfi, Frisium (EU)

Generic?

• No

Class

• Benzodiazepine, antiepileptic drug (AED)

Commonly Prescribed for

(FDA approved in bold)

• Adjunctive treatment of seizures associated with Lennox-Gastaut syndrome (LGS) in patients 2 years of age or older

• Adjunctive therapy for refractory focal seizure, general tonic-clonic seizure, Dravet syndrome, benign epilepsy with centrotemporal spikes, Panayiotopoulos syndrome, catamenial seizure, cluster seizure

• Acute or chronic anxiety

How the Drug Works

• Potentiation of GABAergic neurotransmission resulting from binding to the GABAA receptor

How Long Until It Works

• Tmax = 0.5–4 hours. May take days to weeks

If It Works

• May consider tapering after seizure free for 2 years, depending on the seizure type

If It Doesn't Work

• Consider changing to another agent, adding a second agent, using a medical device, or a referral for epilepsy surgery evaluation. When adding a second agent, keep drug interactions in mind

Best Augmenting Combos for Partial Response or Treatment-Resistance

• Consider a tertiary care or switch to other agents

Tests

• Not required

ADVERSE EFFECTS (AEs)

How the Drug Causes AEs

• CNS inhibitory effect from actions on benzodiazepine receptors

Notable AEs

• Constipation, somnolence, pyrexia, lethargy, drooling, and withdrawal symptoms

Life-Threatening or Dangerous AEs

• Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN)

Weight Gain

• Not unusual

Sedation

• Not unusual

What to Do About AEs

• If SJS or TEN, hospitalization is required

• Discontinue or switch to another agent

Best Augmenting Agents to Reduce AEs

• Most AEs cannot be reduced by an augmenting agent

DOSING AND USE

• 20–40 mg/day twice daily

Dosage Forms

• Tablet: 10 and 20 mg

• Oral suspension: 2.5 mg/mL in 120 mL bottles

How to Dose

• ≤ 30 kg: starting dose 5 mg; starting 7th day 10 mg; starting 14th day 20 mg

• 30 kg: starting dose 10 mg; starting 7th day 20 mg; starting 14th day 40 mg