Week 10 Notes Anti-Epileptic & Psychotherapeutic Drugs PDF

Week 10: **Anti-Epileptic & Psychotherapeutic Drugs** **Epilepsy** - Epilepsy is a CNS syndrome dysfunction causing a spectrum of symptoms from [momentary sensory disturbances] to severe [convulsive seizures.] - Results from excessive electrical activity from neurons located in th...

Week 10: **Anti-Epileptic & Psychotherapeutic Drugs** **Epilepsy** - Epilepsy is a CNS syndrome dysfunction causing a spectrum of symptoms from [momentary sensory disturbances] to severe [convulsive seizures.] - Results from excessive electrical activity from neurons located in the superficial grey matter of the brain. **Seizure** - Brief episode of abnormal electrical activity in nerve cells of the brain, which may or may not lead to a convulsion. **Convulsion** - Involuntary spasmodic contractions of any or all voluntary muscles throughout the body, including skeletal, facial, and ocular muscles. **Epilepsy** - Chronic, recurrent pattern of seizures - Often diagnosed by an electroencephalogram (EEG) **Epilepsy** Most commonly in children and older adults Some evidence to suggest genetic predisposition - [Primary] Epilepsy (idiopathic) Cause cannot be determined. - Roughly 50% of epilepsy cases - [Secondary] Epilepsy (symptomatic) - Distinct cause is identified. - Trauma, infection, cerebrovascular disorder - Most common causes in infants and children include fever, developmental defects, injury at birth, metabolic disease **Classification of Epilepsy** 1. - Loss of consciousness & awareness - Neuronal activity that originates simultaneously in the grey matter of [both] hemispheres a. b. c. d. 2. - Localized or focal region ([one] hemisphere) a. b. c. 3. **Status Epilepticus** - Multiple seizures occur that last 5 minutes or longer - Continuous seizure activity [OR] recurrent seizure activity without recovery between seizures - Result following status epilepticus: Hypotension hypoxia brain damage possibly death - A neurological emergency requiring immediate management to prevent death **Antiepileptic Drugs** - Antiepileptic drugs (*AEDs*) are also known as *anticonvulsants* - Goals of therapy: - To control or prevent seizures while maintaining a reasonable quality of life - To minimize adverse effects and drug-induced toxicity - Antiepileptic drug (AED) therapy is usually **lifelong** although not for all patients - If stopped abruptly withdrawal seizure - Combination of drugs may be used - 70% of patients are generally seizure-free on monotherapy while 30% require multiple drugs **Antiepileptic Drugs** - Single-drug therapy is started before multiple-drug therapy is tried. - Serum drug concentrations **must** be measured. - Therapeutic drug monitoring (specifically dosed individually) - If seizure consistency is [not] improved MRP should order serum drug levels (may not be at therapeutic levels) - Goal: slowly titrate to the lowest effective serum drug level that controls the seizure disorder **Mechanism of Action** - Exact mechanism of action is not known. - May stabilize neuron membranes by reducing movement of electrolytes (e.g., Na, K, Ca, and Mg) **Drug Effects** - Three primary pharmacological effects: 1. Reduce nerve's ability to be stimulated (primarily in motor cortex in frontal lobe) 2. Suppress transmission of seizure impulses from one nerve to the next 3. Decrease speed of nerve impulse conduction within a neuron **Indications** - Prevention or control of seizure activity - Long-term maintenance therapy for chronic, recurring seizures - Acute treatment of convulsions and status epilepticus **Adverse Effects** - [Numerous] adverse effects; vary per drug - Adverse effects often need a change in medication and/or limit drug usefulness - Immune reactions and skin lesions common (**Steven's-Johnson Syndrome** -- similar appearance to burn victims) - Higher incidence of birth defects for mothers with epilepsy (whether on medications or not) **Classification of AEDs:** - Four traditionally used to manage seizure disorders: 1. **Barbituates** 2. **Hydantoins** 3. **Iminostilbenes** 4. **Miscellaneous** 1.**Barbiturates** - **Phenobarbital** - Schedule IV controlled substance - **Indications**: - Generalized seizures - Partial/focal seizures - Most common adverse effect is [sedation]. - Long half-life - Interacts with many drugs **2.Hydantoins** - **Phenytoin** (Dilantin^®^) - *aka Phenytoin sodium* - Has been [used as a first-line] antiepileptic drug for many years and is the [prototypical drug]. - **Indications**: - Generalized seizures - Partial/focal seizures - **Adverse effects**: - Gingival hyperplasia - ++ acne growth - ++ body hair growth in unusual places - IV administration - **[Very irritating to veins]** (pH of 12) -- phlebitis - Slow IV directly into a large vein - Many drug interactions as phenytoin is both [highly protein bound in plasma] (competes for binding sites) as well as induces liver enzymes to [increase metabolism of other drugs] - Exaggerated phenytoin effects with [hypoalbuminemia] (as in malnutrition or chronic kidney failure) - Effective, generally well-tolerated, inexpensive, relatively long half-life **Contraindications**: bradycardia, heart block **3.Iminostilbenes** - **carbamazepine** (Tegretol^®^) - [Second most commonly prescribed antiepileptic drug in Canada after phenytoin] - **Indications**: - Generalized ([ONLY tonic-colonic seizures]) - Partial/focal seizures ([First line treatment]) - **Contraindications**: - Other generalized seizures (myoclonic and absence seizures ) - **Adverse reactions**: headache, dizziness, unusual eye movements, visual change, behavioural change - **Drug interactions**: many - **Miscellaneous Drugs** **4.Miscellaneous Drugs x3** - **gabapentin** (Neurontin^®^) - [Chemical analogue of] gamma-aminobutyric acid ([GABA]), a [neurotransmitter that inhibits brain activity] - **Mechanism of Action**: Believed to work by [increasing the synthesis and synaptic accumulation of GABA] between neurons - **Indications**: Adjunct and prophylactic [tx of partial seizures] - **Contraindication**: known drug allergy - **Adverse effects**: CNS and GI symptoms - **Drug interactions**: alcohol (additive CNS depression) - **levetiracetam** (Keppra^®^) - **Mechanism of Action**: unknown - **Indications**: Adjunct therapy for partial seizures with and without secondary generalization - **Contraindication**: known drug allergy - **Adverse effects**: generally well tolerated, CNS effects - **Drug interactions:** CNS depression when combined with other sedating drugs - **pregabalin** (Lyrica^®^) - Structurally related to GABA & gabapentin - **Indication**: adjunct therapy for partial seizures - [Most common uses are not for seizures: Adjunct therapy for neuropathic pain, postherpetic neuralgia] - **Contraindication**: known drug allergy - **Adverse effects**: dizziness, drowsiness, peripheral edema, blurred vision - Oral use only ***Nursing Implications: Antiepileptics*** - Assessment - Health history, including current medications - Drug allergies - Liver function studies, complete blood count - Baseline vital signs - Oral drugs - Take regularly, same time each day. - Take with meals to reduce GI upset. - Do not crush, chew, or open extended-release forms. - If patient is to take nothing orally (NPO) before a procedure, contact the prescriber regarding AED dosage - **Regular & consistent** dosing is important for successful treatment - Abrupt withdrawal can cause **rebound seizure activity** - IV forms - Monitor vital signs during administration. - Use **only normal saline** (0.9% sodium chloride) with IV phenytoin (Dilantin). - Teach patients to keep a journal to monitor: - Response to drug - Seizure occurrence and descriptions - Adverse effects - ***Do not stop abruptly, must be tapered*** as it can cause **rebound seizure activity** - Wear medical alert tag - Teach patients that therapy is long term and possibly lifelong (not a cure). - Monitor for adverse effects: - Mental status changes, mood changes, changes in level of consciousness or sensorium, eye problems, visual disorders, etc - If antiepileptic medication [does not reduce] frequency of seizures, serum drug levels should be tested to see if therapeutic levels have been reached  **Psychotherapeutic Drugs** **Overview** - Most people experience normal emotions (anxiety, depression, grief) and are often situational - Medication typically considered second line treatment but may be indicated when emotions or behaviours compromise quality of life, social relationships, or important daily activities (including vocational) - Ability to cope with emotions can range from occasional depression or anxiety to constant emotional distress - [Focus will be on three common types of mental health disorders:] 1. Anxiety 2. Affective disorders 3. Psychotic disorders - The etiology of mental health disorders is not clear (numerous theories) - Biochemical imbalance theory attributes the disorder to abnormal levels of neurotransmitters - Some evidence that levels of **dopamine, norepinephrine, serotonin, histamine, GABA (gamma-aminobutyric acid), and acetylcholine** may all play a role in mental health disorders. - Symptoms often overlap and patients may have comorbid conditions making diagnosis and treatment more challenging. **Psychotherapeutic Drugs** - Used in the treatment of emotional and mental disorders - Types of psychotherapeutic drugs used to treat **anxiety**, **affective disorders**, and **psychotic disorders** (some of the most commonly prescribed drugs in Canada): 1. Anxiolytic drugs (anxiety) 2. Mood-stabilizing drugs (affective disorders) 3. Antidepressant drugs (affective disorders) 4. Antipsychotic drugs (psychotic disorders) - Drug effectiveness data is mixed and some experts are concerned that they are over prescribed **1.Anxiolytic Drugs (Anxiety)** - **Anxiety:** - An unpleasant state of mind characterized by a sense of dread and fear - Transient situational anxiety typically differentiated into: 1. significant, 2. persistent symptoms (e.g. \> 6 months) - Symptoms of: feeling on edge, restless, fatigued, difficulty sleeping, trouble concentrating - May be based on anticipated experiences or actual past experiences - May be exaggerated responses to imaginary negative situations - Anxiety different than fear, anxiety is \"a future-oriented mood state in which one is not ready or prepared to attempt to cope with upcoming negative events" (Barlow, 2000) **Distinct Anxiety Disorders** - Separation anxiety disorder - Selective mutism (inability to speak in social situations) - Specific phobia - Social anxiety disorder (social phobia) - Panic disorder - Panic attack - Agoraphobia (fear to public spaces and when escape might be difficult) - Generalized anxiety disorder - Substance- or medication-induced anxiety disorder **Drugs** - All anxiolytic drugs reduce anxiety by [reducing overactivity in the central nervous system (CNS]) - Two drug classes of focus: - **Benzodiazepines** - Depress neurotransmitter activity in the brainstem and limbic system - Miscellaneous drug: **buspirone** (BuSpar^®^) - **Advantage**: [Nonsedating and non--habit forming] - [May have drug interaction with selective serotonin reuptake inhibitors (SSRIs) (serotonin syndrome)] - [Do not administer with monoamine oxidase inhibitors (MAOIs)] **[Benzodiazepines]** Benzodiazepines = aka *Benzo's* - Anti-anxiety -- *minor* tranquilizers - Most contain '**zep**' - All end in '\_\_\_\_**zepam**' or '\_\_\_\_**zolam**' - Remember, Zzzzzs = falling asleep (tranquilizer effect) - [Not designed for long-term use (\