🧠 SLEEP DISORDERS
Medications for Falling Asleep (Sleep Onset Insomnia)
• Zolpidem (Ambien) – short-acting; helps with sleep onset.
• Eszopiclone (Lunesta) – helps with onset and maintenance, but better for onset at lower
doses.
• Ramelteon (Rozerem) – melatonin receptor agonist; specifically for onset.
• Melatonin – endogenous hormone; helpful for shifting circadian rhythm and sleep
onset.
Medications for Staying Asleep (Sleep Maintenance Insomnia)
• Suvorexant (Belsomra), Lemborexant (Dayvigo) – orexin receptor antagonists; improve
sleep maintenance.
• Temazepam (Restoril) – long-acting benzodiazepine; good for maintenance.
• Doxepin (low dose) – tricyclic antidepressant; approved for maintenance insomnia.
• Eszopiclone (Lunesta) – works for both sleep onset and maintenance depending on
dose.
🔬 NEUROANATOMY OF PAIN FIBERS
Types of Pain Neurons
• A-beta fibers: Large diameter, myelinated; conduct non-painful touch, pressure,
vibration. Do not carry pain signals.
• A-delta fibers: Thin, lightly myelinated; transmit sharp, acute pain quickly.
• C fibers: Small, unmyelinated; conduct slow, dull, burning or chronic pain.
🔥 PAIN PATHOPHYSIOLOGY
Peripheral Neuropathy Pain
• Damage to peripheral nerves (trauma, diabetes, toxins).
, • Common symptoms: burning, tingling, electric shocks, allodynia, numbness.
• Involves C-fiber dysfunction; hyperexcitability and loss of inhibitory control.
Chronic Pain – Pathophysiology
• Transition from acute to chronic pain via central sensitization.
• Persistent activation of pain circuits → changes in: o Amygdala – emotional memory of
pain. o Anterior cingulate cortex – pain attention.
o Prefrontal cortex – pain evaluation.
• Pain memory becomes autonomous from peripheral input.
• Chronic pain is linked to the limbic system and default mode network.
😰 ANXIETY DISORDERS – NEUROPATHOPHYSIOLOGY
• Amygdala hyperactivity: fear response, threat detection.
• Hippocampus: contextual memory (trauma link).
• Prefrontal cortex (hypoactivity): poor regulation of fear.
• Bed nucleus of the stria terminalis (BNST): anticipatory anxiety.
• Neurotransmitters involved: GABA (↓), serotonin (↓), norepinephrine (↑), CRF (↑).
🚨 OVERDOSE SIGNS & MANAGEMENT
Benzodiazepines (e.g., Xanax, Valium)
• S/S: CNS depression, drowsiness, confusion, hypotonia, respiratory depression (if
combined).
• Treatment: Flumazenil (Romazicon) – GABA-A antagonist.
Opioids
• S/S: Respiratory depression, pinpoint pupils, unconsciousness.
• Treatment: Naloxone (Narcan) – opioid antagonist.
Stimulants (e.g., Modafinil)
• S/S: Agitation, tachycardia, HTN, psychosis.
• Treatment: Benzodiazepines for agitation, cardiac monitoring.
TCAs (e.g., Amitriptyline)
• S/S: Arrhythmias, seizures, anticholinergic signs, coma.