Anxiety Medications Lecture Notes PDF

Anxiety Medications Lecture Notes **Key Neurotransmitters in Anxiety** 1\. **GABA (Gamma-Aminobutyric Acid)** The primary inhibitory neurotransmitter in the brain. Enhancing GABAergic activity typically results in calming and sedative effects. 2\. **Serotonin (5-HT)** Involved in mood regul...

Anxiety Medications Lecture Notes **Key Neurotransmitters in Anxiety** 1\. **GABA (Gamma-Aminobutyric Acid)** The primary inhibitory neurotransmitter in the brain. Enhancing GABAergic activity typically results in calming and sedative effects. 2\. **Serotonin (5-HT)** Involved in mood regulation and anxiety. Many anxiolytics work by increasing serotonin levels in the brain (e.g., SSRIs). 3\. **Norepinephrine (NE)** Plays a role in the "fight or flight" response. Inhibiting excessive norepinephrine activity can help reduce anxiety. 4\. **Glutamate** The primary excitatory neurotransmitter. Drugs that modulate glutamatergic activity can also have anxiolytic effects, although this is less common. **Benzodiazepines** - **Mechanism of Action:** Enhance GABAergic transmission by binding to GABA-A receptors, which increases the frequency of chloride channel opening and leads to hyperpolarization of the neuron, reducing excitability. - **Effects:** Rapid onset of action with sedative, hypnotic, anxiolytic, muscle relaxant, and anticonvulsant properties. **Clinical Applications:** **Fast-Onset Benzodiazepines (15-30 minutes)** These are used when **rapid relief** is needed, especially in acute situations where immediate control of anxiety, panic, or other symptoms is critical. **Clinical Applications:** 1\. **Panic Attacks**: **Alprazolam (Xanax)** and **Diazepam (Valium)** are often prescribed for **acute panic attacks** due to their rapid onset. They can quickly alleviate severe anxiety and prevent the escalation of panic symptoms. **Diazepam** is sometimes preferred because of its longer half-life, providing sustained relief after the initial effect. 2\. **Acute Anxiety Episodes**: **Alprazolam** is used for patients with **panic disorder** or **acute anxiety** who need immediate relief in high-stress situations. **Diazepam** may also be used for rapid management of **situational anxiety** (e.g., before medical procedures or in emergency room settings for severe anxiety). 3\. **Seizures**: **Diazepam (Valium)** is commonly used for the rapid control of **acute seizures** in the emergency setting, especially for **status epilepticus**. It is often administered via intravenous (IV) or rectal routes for a quick effect. 4\. **Alcohol Withdrawal**: Fast-onset benzodiazepines like **diazepam** or **chlordiazepoxide** are often used to manage **alcohol withdrawal symptoms**, such as agitation, tremors, and the risk of seizures. Diazepam's rapid onset helps to prevent withdrawal complications. 5\. **Muscle Spasms**: **Diazepam** is also used to quickly relieve **muscle spasms** or **tension** due to its muscle-relaxing properties. **Intermediate-Onset Benzodiazepines (30-60 minutes)** These are used when **moderate speed of relief** is needed, balancing rapid effects with a slightly longer duration of action. They are preferred for **sustained symptom control** without the intense peaks and troughs associated with very fast-onset drugs. **Clinical Applications:** 1\. **Generalized Anxiety Disorder (GAD)**: **Lorazepam (Ativan)** and **Clonazepam (Klonopin)** are commonly used in the management of **generalized anxiety disorder** (GAD). They help manage **persistent anxiety** without the need for as frequent dosing. **Clonazepam** has a longer half-life, making it ideal for **longer-term symptom control** without frequent redosing, which can improve compliance. 2\. **Short-term Management of Anxiety**: **Lorazepam** is often used for **short-term anxiety** associated with medical procedures, dental work, or other stressful events. Its intermediate onset makes it helpful for managing anxiety **during hospital stays** or **before surgery**. 3\. **Acute Mania or Agitation**: **Lorazepam** is commonly used in the **acute management of mania or agitation**, especially in **bipolar disorder** or **schizophrenia**. It can be administered orally or via injection (IV/IM) to provide calming effects without excessive sedation. 4\. **Seizure Disorders**: **Clonazepam** is used as an **adjunctive treatment for epilepsy**, particularly for **absence seizures** or **myoclonic seizures**, where longer-term control is needed but with relatively quick symptom management. 5\. **Insomnia (Short-term)**: **Temazepam (Restoril)** is prescribed for **insomnia**, particularly for patients who experience **sleep-onset difficulties**. Its intermediate onset helps patients fall asleep without causing excessive morning sedation. **Slow-Onset Benzodiazepines (1-2 hours)** These are primarily used in situations where **gradual relief** is acceptable or even preferred. Their slower onset makes them less likely to be abused for the immediate euphoric effects, so they are useful in more controlled, chronic situations. **Clinical Applications:** 1\. **Chronic Anxiety Disorders**: **Oxazepam (Serax)** and **Chlordiazepoxide (Librium)** are used for **chronic anxiety**, particularly **Panic Attacks**: **Alprazolam (Xanax)** and **Diazepam (Valium)** are often prescribed for **acute panic attacks** due to their rapid onset. They can quickly alleviate severe anxiety and prevent the escalation of panic symptoms. **Diazepam** is sometimes preferred because of its longer half-life, providing sustained relief after the initial effect. **Acute Anxiety Episodes**: **Alprazolam** is used for patients with **panic disorder** or **acute anxiety** who need immediate relief in high-stress situations. **Diazepam** may also be used for rapid management of **situational anxiety** (e.g., before medical procedures or in emergency room settings for severe anxiety). **Selective Serotonin Reuptake Inhibitors (SSRIs)** **Mechanism of Action:** Inhibit the reuptake of serotonin (5-HT) into the presynaptic neuron, increasing serotonin availability in the synaptic cleft. **Effects:** Over time, increased serotonin transmission helps reduce anxiety, though the onset of action can take 2--6 weeks. **Common Drugs:** **Sertraline (Zoloft)** **Paroxetine (Paxil)** **Escitalopram (Lexapro)** **Fluoxetine (Prozac)** **Indications:** First-line treatment for generalized anxiety disorder, panic disorder, social anxiety disorder, obsessive-compulsive disorder (OCD), and post-traumatic stress disorder (PTSD). **Considerations:** Initial side effects may include increased anxiety, insomnia, nausea, and sexual dysfunction. SSRIs are generally well-tolerated for long-term use and have a lower risk of dependence compared to benzodiazepines. **Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs)** **Mechanism of Action:** Inhibit the reuptake of both serotonin and norepinephrine, increasing the availability of these neurotransmitters. **Effects:** Improve both anxiety and depressive symptoms by modulating serotonin and norepinephrine pathways. **Common Drugs:** **Venlafaxine (Effexor)** **Duloxetine (Cymbalta)** **Indications:** Generalized anxiety disorder, social anxiety disorder, panic disorder, and comorbid anxiety with depression. **Considerations:** Like SSRIs, SNRIs take several weeks to show full therapeutic effects. Common side effects include increased blood pressure (especially with venlafaxine), insomnia, and nausea. **Buspirone (Buspar)** **Mechanism of Action:** A serotonin 5-HT1A receptor partial agonist. It has a distinct mechanism compared to SSRIs and benzodiazepines, modulating serotonin without significant GABA effects. **Effects:** Provides anxiolytic effects without sedation, dependence, or withdrawal issues, making it an attractive option for long-term use. **Indications:** Generalized anxiety disorder, and sometimes used adjunctively in depression or for patients with substance abuse risks. **Considerations:** Buspirone takes 2--4 weeks to achieve full efficacy. It is generally well-tolerated, but may cause dizziness, headaches, and nausea. **Beta-blockers (e.g., Propranolol)** **Mechanism of Action:** Block peripheral effects of norepinephrine and epinephrine by antagonizing beta-adrenergic receptors. **Effects:** Reduce physical symptoms of anxiety, such as heart palpitations, tremors, and sweating, without directly affecting mood or cognition. **Common Drugs:** **Propranolol (Inderal)** **Indications:** Performance anxiety, situational anxiety, and sometimes used adjunctively for PTSD. **Considerations:** Propranolol is effective for reducing somatic symptoms of anxiety (e.g., rapid heart rate) but is not used for long-term treatment of generalized anxiety. **Antihistamines** **Mechanism of Action:** Sedative effects result from blocking histamine H1 receptors in the brain. **Common Drugs:** **Hydroxyzine (Vistaril, Atarax)** **Indications:** Short-term treatment of anxiety, often used when there is a need for an anxiolytic with no risk of addiction or when benzodiazepines are contraindicated. **Considerations:** Can cause drowsiness and dry mouth. Less effective for severe anxiety disorders but useful in mild or situational anxiety. **Atypical Antipsychotics (e.g., Quetiapine)** **Mechanism of Action:** Though primarily used for psychosis and mood disorders, certain atypical antipsychotics have shown anxiolytic effects, likely due to their action on serotonin and dopamine receptors. **Common Drugs:** **Quetiapine (Seroquel)** **Indications:** Used off-label for treatment-resistant anxiety disorders or as augmentation for anxiety with comorbid mood disorders. **Considerations:** Side effects include sedation, weight gain, and metabolic syndrome risks. Reserved for patients who do not respond to first-line treatments. **Gabapentinoids** **Mechanism of Action:** Structurally related to GABA but does not directly bind to GABA receptors. Instead, it modulates calcium channels and may reduce excitatory neurotransmitter release. **Common Drugs:** **Gabapentin (Neurontin)** **Pregabalin (Lyrica)** **Indications:** Used off-label for anxiety, particularly generalized anxiety disorder and anxiety with comorbid pain syndromes. **Considerations:** Generally well-tolerated, but can cause sedation, dizziness, and weight gain. **Considerations for Prescribing Anxiolytics** **Short-term vs. Long-term Treatment:** Benzodiazepines are effective for acute anxiety but are generally avoided for long-term use due to the risk of tolerance and dependence. SSRIs, SNRIs, and buspirone are better suited for long-term management. **Comorbid Conditions:** Many patients with anxiety also experience depression, and SSRIs/SNRIs are beneficial for both conditions. **Side Effects and Safety:** Monitoring for side effects such as sedation (especially with benzodiazepines and antipsychotics), weight gain (with antipsychotics), and cardiovascular effects (with beta-blockers and SNRIs) is essential.