perampanel: clinical use

Prescribing considerations

• Use as adjunctive therapy and individualise treatment according to seizure response and tolerability.
• Review renal and hepatic function: use is not recommended in moderate or severe renal impairment, haemodialysis or severe hepatic impairment.
• Consider falls, polypharmacy and interaction risk in older people.
• Assess whether continuity of manufacturer is clinically important before switching products.
• Counsel patients and carers about behavioural changes, suicidality and severe skin reactions.

Contraindications and cautions

• Hypersensitivity to perampanel or a formulation excipient.
• Do not restart after perampanel-associated Stevens–Johnson syndrome or DRESS.
• Tablet formulations containing lactose are unsuitable for specified rare hereditary lactose-related disorders.
• The sorbitol-containing suspension should not be used in hereditary fructose intolerance.

Monitoring

• Seizure pattern and clinical response, especially when enzyme inducers are added or withdrawn.
• Mood, aggression, suicidality, psychosis and substance misuse behaviours.
• Dizziness, somnolence, coordination, gait and falls.
• New rash, fever, lymphadenopathy or other evidence of severe hypersensitivity.
• Absence or myoclonic seizures, which may worsen in some people with generalised epilepsy.
• Liver function if hepatic enzyme elevation or hepatotoxicity is suspected.

Clinical pharmacology

Perampanel is a selective, non-competitive postsynaptic AMPA glutamate-receptor antagonist. It is highly protein-bound, primarily metabolised through CYP3A-mediated oxidation followed by glucuronidation, and has a long elimination half-life that is shortened by strong enzyme inducers.

Formulation and product differences

• Film-coated tablets contain lactose and must be swallowed whole because they cannot be divided accurately.
• The oral suspension contains sorbitol and benzoates and is supplied with oral syringes and a press-in bottle adapter.
• The suspension requires shaking and careful measurement; switching between tablet and suspension formulations should be cautious.

Oral suspension

Route: Oral

Strengths: 0.5 mg/mL

Tablet

Route: Oral

Strengths: 2 mg, 4 mg, 6 mg, 8 mg, 10 mg, 12 mg