Neurological and Pharmacological Agents Practice Flashcards

Practice vocabulary flashcards covering anticonvulsants, antiparkinson agents, analgesics, and anaesthetics based on lecture material.

Epilepsy

A tendency of the brain to generate seizures caused by groups of cortical neurons firing in an abnormal, excessive, and synchronous way.

Partial (Focal) Seizures

Seizures where the abnormal discharge begins in one localized spot and stays localized, typically without loss of consciousness.

Secondary Generalization

The process by which a partial seizure recruits the rest of the brain through subcortical pathways to become a generalized seizure.

Tonic-Clonic (Grand Mal) Seizures

Generalized seizures involving a tonic phase of sustained muscle contraction followed by a clonic phase of rhythmic jerking.

Absence (Petit Mal) Seizures

Seizures involving a brief $3\,Hz$ spike-and-wave discharge in thalamocortical circuits, resulting in a blank stare and interrupted speech without falling.

Status Epilepticus

A medical emergency characterized by a seizure or repeated seizures without recovery in between that lasts long enough to require fast-acting IV drugs.

Vigabatrin

An anticonvulsant that irreversibly blocks GABA transaminase, the enzyme in astrocytes that normally breaks down GABA.

Tiagabine

An anticonvulsant that blocks the reuptake of GABA back into neurons or glia after it has been released.

Use-dependent Blockade

A property of drugs like phenytoin where the drug binds preferentially to sodium channels in the inactivated state, selectively dampening rapidly firing neurons.

Phenytoin Pharmacokinetics

Characterized by high protein binding (~$90\%\text{}$) and saturable (zero-order) metabolism, giving it a narrow therapeutic index.

Carbamazepine Autoinduction

The process where carbamazepine induces the CYP3A4 enzymes that metabolize it, increasing its own clearance over the first $2\text{--}4\text{}$ weeks of treatment.

Sodium Valproate

A broad-spectrum anticonvulsant that acts via sodium channel blockade, T-type calcium channel blockade, and inhibition of GABA transaminase.

Levetiracetam

A newer anticonvulsant that binds SV2A, a synaptic vesicle protein, and is mostly renally excreted with minimal hepatic metabolism.

Gabapentin

A structural GABA analogue that does not act on GABA receptors, but binds the $\alpha 2 \delta$ subunit of voltage-gated calcium channels.

Substantia Nigra Pars Compacta (SNpc)

The motor circuit structure containing dopaminergic neurons that die off in Parkinson’s disease.

Lewy Bodies

Abnormal protein aggregates of misfolded alpha-synuclein found inside neurons in Parkinson’s disease.

Parkinson’s Cardinal Motor Symptoms

Bradykinesia (slow movement), rigidity (elevated muscle tone), tremor (resting), and postural instability.

Levodopa

The gold standard PD therapy; a precursor that crosses the blood-brain barrier and is converted to dopamine by dopa-decarboxylase.

Carbidopa

A peripheral dopa-decarboxylase inhibitor that does not cross the blood-brain barrier, used to prevent the peripheral conversion of levodopa to dopamine.

Nociception

The physiological process of detecting a noxious stimulus by specialized receptors, distinct from the subjective feeling of pain.

Neuropathic Pain

Pain arising from damage or dysfunction in the nervous system’s own sensory pathways rather than ongoing tissue injury.

Hyperalgesia

An exaggerated pain response to a stimulus that would normally cause only mild pain.

Allodynia

Pain triggered by a stimulus that should not be painful at all, such as a light touch.

Mu ($\mu$) Receptor

The main clinical target for opioids, responsible for strong analgesia, euphoria, and respiratory depression.

Naloxone

A competitive mu-receptor antagonist with a rapid onset and short half-life used for emergency opioid reversal.

NSAID Mechanism

The inhibition of the enzyme cyclo-oxygenase (COX) to reduce the production of pain-sensitizing prostaglandins.

NAPQI

A toxic metabolite of paracetamol produced via CYP2E1 that causes hepatic necrosis when glutathione stores are depleted.

Minimum Alveolar Concentration (MAC)

The concentration of an inhalational anaesthetic needed to prevent movement to surgical incision in $50\%\text{}$ of patients.

Dissociative Anaesthesia

A state produced by ketamine where the patient is functionally disconnected from pain and awareness while potentially retaining reflexes and open eyes.

Malignant Hyperthermia

A rare genetic disorder where volatile anaesthetics or succinylcholine trigger uncontrolled calcium release in skeletal muscle, causing severe hypermetabolism and fever.

Amide Local Anaesthetics

A class of local anaesthetics (e.g., lidocaine, bupivacaine) metabolized by hepatic microsomal enzymes and associated with a lower allergy risk than esters.

Local Anaesthetic Systemic Toxicity (LAST)

A condition presenting with CNS toxicity (seizures) followed by CVS toxicity (arrhythmias/arrest), treated with IV lipid emulsion.

Succinylcholine

A depolarising neuromuscular blocker that binds nicotinic ACh receptors, causing initial fasciculations before persistent flaccid paralysis.

Non-Depolarising Neuromuscular Blockers

Competitive antagonists at nicotinic ACh receptors (e.g., vecuronium) that produce paralysis without initial fasciculation.