Central Nervous System Drugs: Antiepileptics, Antiparkinsonian, and Psychotherapeutic Agents

Vocabulary and key concept flashcards covering pharmacological treatments for epilepsy, Parkinson's disease, and mental health disorders as described in chapters 15, 16, and 17.

Seizure

A brief episode of abnormal electrical activity in the brain.

Convulsion

Involuntary spasmodic contractions of any or all voluntary muscles throughout the body.

Epilepsy

A chronic, recurrent pattern of seizures.

Primary or Idiopathic Epilepsy

A form of epilepsy where the cause cannot be determined, accounting for more than 50% of cases.

Secondary Epilepsy

Epilepsy with a distinct cause identified, such as trauma, infection, cerebrovascular disorder, or brain injury.

Partial Seizures

Previously known as Petit Mal; classified into simple (awake) and complex (altered level of consciousness) seizures.

Generalized Seizures

Previously known as Grand Mal or Tonic-Clonic Seizures.

Status Epilepticus

A life-threatening emergency characterized by constant firing of nerve impulses to the brain without relief or recovery between attacks.

Antiepileptic Drugs (AEDs) Goal

To control or prevent seizures while maintaining a reasonable quality of life and minimizing side effects and drug-induced toxicity.

AED Mechanism of Action

Stabilizes neurons through electrolyte balance and decreases neuron hyperexcitability by suppressing impulse transmission from one nerve to the next.

First-line drugs for acute seizures

Benzodiazepines, such as lorazepam (Ativan®) $1-2\,mg$ or diazepam (Valium®) $5-10\,mg$ IV.

Phenytoin (Dilantin®)

A maintenance AED that is highly protein bound, a CytP450 inducer, and may cause gingival hypertrophy and Dilantin facies.

Carbamazepine (Tegretol®)

Chemically similar to TCAs, it inactivates sodium channels and is a GABA agonist; contraindicated in bone marrow depression.

Valproic acid (Depakote®)

Used for absence, myoclonic, and resistance seizures; side effects include weight gain, hepatotoxicity, and pancreatitis.

Parkinson’s Disease (PD)

A chronic, progressive, degenerative disorder caused by an imbalance of dopamine (inhibitor) and acetylcholine (stimulator) in the basal ganglia.

TRAP Mnemonic

Common symptoms of Parkinson’s: Tremor, Rigidity, Akinesia, and Postural instability.

Bradykinesia

A classic Parkinsonian symptom described as slowness of movement.

Akinesia

Absence of psychomotor activity, resulting in a masklike facial expression.

Chorea

Irregular, spasmodic, involuntary movements of the limbs or facial muscles.

Dystonia

Abnormal muscle tone leading to impaired or abnormal movements.

On–off phenomenon

Rapid swings in response to levodopa where PD worsens with too little dopamine and dyskinesia occurs with too much.

Selegiline

A selective MAOI used as an adjunct with levodopa that increases dopaminergic stimulation without the ‘cheese effect’ at doses of $10\,mg$ or less.

Amantadine

A dopamine modulator that causes the release of dopamine and blocks its reuptake; originally an antiviral for influenza.

Entacapone

A COMT inhibitor that prolongs the duration of levodopa action and may cause urine discoloration.

Bromocriptine

A direct-acting dopamine receptor agonist (ergot derivative) that stimulates production of more dopamine; used with caution in peripheral vascular disease.

Levodopa-Carbidopa (Sinemet)

Levodopa is a dopamine precursor that crosses the BBB; Carbidopa prevents its peripheral breakdown.

Benztropine (Cogentin®)

An anticholinergic used for PD and extrapyramidal symptoms (EPS) from antipsychotic drugs; treats muscle tremors and rigidity.

Anxiety

An unpleasant state of mind characterized by a sense of dread and fear, potentially based on actual or anticipated experiences.

Affective Mood Disorder

Changes in mood ranging from mania (abnormally pronounced emotions) to depression (abnormally reduced emotions).

Psychosis

A severe emotional disorder characterized by a loss of contact with reality and impairment of mental functions needed for daily living.

SSRIs (Serotonin-selective reuptake inhibitors)

Second-generation antidepressants that selectively inhibit serotonin reuptake, enhancing mood with little effect on the cardiovascular system.

Serotonin Syndrome

A consequence of enhanced serotonin activity presenting with delirium, agitation, tachycardia, sweating, myoclonus, and hyperreflexia.

TCAs (Tricyclic Antidepressants)

First-generation antidepressants like amitriptyline (Elavil®) that block norepinephrine and serotonin reuptake; overdose is lethal due to seizures and dysrhythmias.

MAOIs (Monoamine Oxidase Inhibitors)

Antidepressants that inhibit the MAO enzyme system; requires a tyramine-free diet to avoid the ‘cheese effect’ or hypertensive crisis.

Tyramine

An amino acid found in aged cheeses, smoked meats, and red wine that causes hypertensive crisis when combined with MAOIs.

Flumazenil (Anexate)

The antidote for benzodiazepine overdose.