AED

Question 1

Explain what is Epilepsy

Answer 1

A continuing tendancy to have seizures, which are sudden discharges of abnormal electrical activity

Question 2

Pheytoin

Answer 2

Block voltage gated Na+channels at high firing frequencies, therefore us dependant Used in treat many forms of seizure but not absence seizures. Side effects: Zero order kinetics/saturation kinetics - monitor plasma conc to avoid toxicity. May cause local necrosis, cerebellar damage, confusion, gum hyperplasia, osteoporosis

Question 3

Ethosuximide, Zonisamide

Answer 3

Block T-type Ca2+ channels Used to treat absence seizures in children Side effects: Nauzea and Anorexia

Question 4

Carbamazepine, Oxcarbazepine

Answer 4

Carbamazepine

• Mimics tricyclic acid(antidepressant).
• Block voltage gated sodium channels at high firing frequency - use dependant Used in partial seizures and trigeminal neuralgia but worsening Juvenile Myoclonic Epilepsy.
• Side effects: Sedation, Mental disturbances, water retention

Oxcarbazepine Similar to Carbamazepine but less toxic, fewer side effects.

Question 5

Valporate 1st choice

Answer 5

Increase content of GABA (inhibitory neurotransmitter) by inhibiting GABA transaminases.

Also blocks Na+ channels Used as drug of first choice as well tolerated

Few but serious side effects including foetal abnormalities, therefore not used in pregnancy.

Question 6

Lorazepam, Diazepam

Answer 6

Benzodiazepine

Allosterically acting on GABAa receptors. Opening of Cl channels cause membrane hyperpolarisation to potentiate the inhibitory effect of GABA.

Used to treat status epilepticus (IV 4mg of Lorazepam)

Sedating (A1) and Anxiolytic (A2)

Question 7

Lamotrogiene

Answer 7

Blocks voltage gated Na+ channels. Broad therapeutic profile therefore commonly used. Well tolerated in pregnancy Side effects: Hypersensitivity (e.g skin rashes esp used with Valporate)

Question 8

Levetiracetam

Answer 8

Analogue of piracetam (used to improve cognitive function). Probably inhibit presynaptic Ca2+ channels Used in treating partial and generalised seizures

Question 9

Gabapentin, Pregabalin

Answer 9

Block specific Ca2+ channel subunits A2G1

Neuropathic pain

Question 10

Status Epilepticus

Answer 10

Lorazepam/Diazepam IV 4mg followed by pheytoin when control is established

Question 11

Baclofen

Answer 11

GABAb receptor agonist, to inhibit motorneurons at spinal cord level Primary antispasm drugs associated with MS and spinal cord injury Side efffects: Drowsieness, Induce depression if withdrawn quickly

Question 12

Classifcation of Seizures

Answer 12