Neuropharmacology Flashcards
Perampanel
AMPA antagonist, antiepileptic (specifically for partial seizures)
Memantine
NMDA channel blocker for Alzheimer’s.
Ketamine
NMDA channel blocker, anaesthetic, has antidepressant action not currently used as antidepressant.
Baclofen
GABA(B) agonist, a muscle relaxant used to treat spasticity in MS patients
Bicuculline
GABA(A) antagonist, pro-epileptic
Picrotoxin
GABA(A) antagonist + glycine receptor antagonist, pro-epileptic
Thiopental
Short acting barbiturate, GABA(A) PAM: enhances the magnitude of GABA(A) currents.
Rarely used anaesthetic, used for lethal injection
Phenobarbital
Long acting barbiturate, GABA(A) PAM: enhances the magnitude of GABA(A) currents
Rarely used antiepileptic due to sedative side effect with overdose causing respiratory failure.
Activates PXR to upregulate CYP3A4.
Diazepam
Benzodiazepine, enhances GABA(A) response to GABA, used to treat anxiety and status epilepticus. Long acting drug so has issue of tolerance to the drug and dependence (abrupt withdrawal causes heightened anxiety). Sedative side effect.
Lorazepam
Short acting benzodiazepine, enhances GABA(A) response to GABA, used as sedative and status epilepticus. Lorazepam is 10 times more powerful than diazepam as a sedative so must be used with care.
Flumazenil
Benzodiazepine antagonist, used to treat benzodiazepine overdose.
Zolpidem
‘Z’ drug (NOT a benzodiazepine) acts at GABA(A) benzodiazepine site. Also enhances GABA(A) response to GABA (P.35 notes).
Sedative used in the treatment of insomnia but causes people to sleepwalk!
Less addictive than benzodiazepines. Short acting.
AP5
Competitive NMDA antagonist
ACET
Kainate receptor antagonist
CNBX, NBQX
Competitive AMPA antagonists
βCCE
Inverse agonist at GABA(A)
Vigabatrin
Irreversible GABA transaminase inhibitor, antiepileptic (all forms apart from absence seizures due to GABA reactivating T-type Cav channels)
Tiagabine
Inhibits GAT1, antiepileptic (all forms apart from absence seizures due to GABA reactivating T-type Cav channels)
Carbamazepine
Nav blocker, antiepileptic (all forms apart from absence seizures), used for neuropathic pain.
Prodrug activated by CYP enzymes to active epoxide, metabolised by microsomal EH.
Phenytoin
Nav blocker, antiepileptic (all forms apart from absence seizures).
(1) 80-90% bound to plasma albumin (so an increase in dose will cause a disproportionate increase in Cfree).
(2) Metabolised by CYP2C9 and CYP2C19, then by glucuronidation.
(3) Therapeutic doses saturate hydroxylation by CYP2C9 pathway so elimination follows zero order kinetics. So an increase in rate of infusion cause a massive increase in plasma concentration.
(4) Inhibits CYP2C9 (together with valproate). Inhibits glucuronidation (together with pentobarbital, issue for paracetamol overdose).
(5) CYP2C19 is highly polymorphic, especially in Asians.
(6) Overdose can increase seizure frequency
Lamotrigine
Nav blocker, antiepileptic (all forms including absence seizures), used for bipolar disorder and neuropathic pain.
Lacosamide
Inactivates Nav by enhancing slow inactivation, meaning Navs are less available for activation (involves structural rearrangement), antiepileptic (specifically for partial seizures).
Ethosuximide
T-type Cav blocker, antiepileptic (specifically for absence seizures)
Valproate (sodium valproate, valproic acid)
T-type Cav blocker, Nav blocker, weakly inhibits GABA transaminase, enhances GABA function, antiepileptic (treats all kinds) Inhibits microsomal EH (issue for carabamazepine metabolism) Inhibits CYP2C9 (issue for phenytoin metabolism)
Gabapentin + Pregabalin
Binds α2δ subunits so reduces Cav plasma membrane expression, antiepileptic (specifically for partial and absence seizures), used for neuropathic pain.
Topiramate
Blocks Nav, Cav, AMPA receptors, enhances GABA(A) function, antiepileptic (treats all kinds), anti-migraine.
Zonisamide
Blocks Nav, Cav, enhances GABA(A) function, antiepileptic (treats all kinds).
Retigabine
Kv7.2 channel opener, antiepileptic (specifically for partial seizures).
Levetiracetam
Binds SV2A (synaptic vesicle protein 2A), antiepileptic (treats all kinds).