DP

Unit 27: Medications Affecting the Nervous System Notes

ANALGESICS

  • Definition: Medications that relieve different types of pain (headache, injuries, arthritis).
  • Subtypes:
    • Analgesics can be anti-inflammatory analgesics (reduce inflammation).
    • Opioid analgesics change the way the brain perceives pain.
  • Accessibility: Some analgesics are sold over the counter (OTC); others require a prescription.
  • Key concept: Relieve pain without loss of consciousness.
  • Real-world relevance: Widely used in clinical and non-clinical settings for pain management; important to understand prescription vs OTC access and potential side effects.

OPIATES vs OPIOIDS

  • Opiates: Natural or synthetic drugs derived from morphine.
    • Examples: codeine, Dilaudid, oxycodone.
  • Opioids: Synthetic drugs not related to morphine that mimic morphine’s action.
  • Relationship: Opiates are a subset of opioids; both aim to reduce pain but differ in origin.
  • Real-world relevance: Key in managing moderate-to-severe pain; high addiction potential necessitates counseling on risks and benefits.

NARCOTICS

  • Definition: Opioids are drugs prescribed to manage moderate to severe pain; also sometimes for chronic coughing and diarrhea.
  • Addiction potential: High; discuss risks and benefits with a provider before use.
  • Mechanism: Opioids are chemicals (natural or synthetic) that interact with nerve cells to reduce pain.
  • Real-world relevance: Central to pain management, palliative care, and cough/diarrhea treatment; require careful monitoring.

NARCOTIC ANTAGONISTS

  • Antagonist: A substance that blocks or reverses the effects of opioids.
  • Naloxone HCl:
    • FDA-approved medicine to rapidly reverse opioid overdose.
    • Mechanism: Attaches to opioid receptors, reversing/ blocking effects of other opioids.
    • Administration routes: IV, subcutaneous (SC), intramuscular (IM), or intranasal.
  • Real-world relevance: Critical in emergency response to overdoses; training often provided to laypersons.

ANALGESIC-ANTIPYRETICS

  • Antipyretic definition: A substance that reduces fever.
  • Mechanism: Lowers fever by causing the hypothalamus to override prostaglandin-induced temperature rise.
  • Common agents in the US:
    • NSAIDs with antipyretic properties: ibuprofen, aspirin (also anti-inflammatory analgesics).
    • Acetaminophen: analgesic with no anti-inflammatory properties.
  • Relationship to other uses: Many antipyretics have analgesic and anti-inflammatory effects; choice depends on desired properties and comorbidities.
  • Real-world relevance: Fever management in infections, inflammatory conditions; NSAIDs carry GI/bleeding risk; acetaminophen has hepatotoxicity risk at high doses.

SEDATIVES & HYPNOTICS

  • Sedatives: Drugs that induce a calming effect; CNS depressants that slow brain activity.
  • Hypnotics: Drugs that induce sleep; at higher doses can be used for general anesthesia.
  • Real-world relevance: Used in anxiety management, sleep disorders, and anesthesia; misuse potential with sedatives/hypnotics.

BENZODIAZEPINES

  • Mechanism: Slow down brain and nervous system activity by enhancing GABAergic inhibition (general mechanism not detailed in transcript but implied by class).
  • Uses: Treat anxiety, seizures, insomnia, and related mental health conditions.
  • Abuse potential: Higher with long-term use or improper administration.
  • Real-world relevance: Common in clinical practice for short-term anxiety and seizure management; require careful prescribing due to dependency risk.

ANTI-PARKINSONIAN DRUGS

  • Parkinson’s disease basics:
    • Neurotransmitter imbalance: acetylcholine and dopamine in the brain.
    • No cure; treatment focuses on symptom relief.
    • Progressive neurological condition affecting movement.
  • Treatments:
    • Several types exist; most common is Levodopa.
    • Most patients take a combination of medications.
  • Levodopa specifics:
    • Dopamine replacement agent.
    • Crosses the blood-brain barrier (BBB) and is converted to dopamine in the CNS and peripheral nervous system.
  • Real-world relevance: Core aspect of managing motor symptoms in Parkinson’s; combinational therapy often targets multiple pathways to maximize benefit and minimize side effects.

ALZHEIMER’S DISEASE

  • Definition: Neurodegenerative disease characterized by amyloid plaque deposits between brain cells; typically begins after age 60.
  • Prognosis: No cure; medications help alleviate symptoms; disease worsens over time.
  • Common symptoms: Mood changes, disorientation/confusion, memory loss, misplacing items, impaired balance/equilibrium, personality changes.
  • Etiology: Amyloid plaques contribute to neural dysfunction; exact mechanisms are complex.
  • Real-world relevance: Major cause of dementia; management focuses on symptom relief and quality of life.

ALZHEIMER’S DISEASE – TREATMENT OPTIONS

  • Cholinesterase inhibitors:
    • Mechanism: Block acetylcholinesterase, the enzyme that destroys acetylcholine.
    • Role: Support communication between nerve cells.
  • NMDA antagonists:
    • Mechanism: Block NMDA receptors when they are excessively active.
    • Role: Modulate excitotoxicity associated with neurodegeneration.
  • Other treatments:
    • Antidepressants and antipsychotics may be used to manage associated symptoms.
  • Real-world relevance: Pharmacologic strategies aim to slow progression and manage behavioral/psychological symptoms, though efficacy varies.

ANTICONVULSANTS

  • Epilepsy overview:
    • A disorder with abnormal electrical activity in the brain.
  • Anticonvulsants/antiseizure medications:
    • Mechanisms: Work in different ways to either reduce neuronal excitation or promote inhibition of electrical signaling.
  • Neuronal basics:
    • Neurons: Resting, excited (triggering), or inhibiting other neurons; antiseizure meds modulate these processes.
  • Real-world relevance: Essential for seizure control; choice depends on seizure type and patient factors.

ANESTHETICS

  • General concept: Anesthetics interfere with nerve impulse conduction and can induce loss of sensation; depending on the agent, can cause loss of consciousness (General Anesthesia).
  • Local anesthetics: Produce loss of sensation in a specific area (e.g., for suturing).
  • Examples: Lidocaine, Marcaine, Novacaine.
  • Real-world relevance: Critical in surgical procedures, dental work, and minor medical procedures requiring pain control.

OPHTHALMIC DRUGS

  • Formulation: Administered via eye instillation as drops, gels, or ointments.
  • Role: Antiinfectives that kill or inhibit the spread of infection in the eye.
  • Indications: Glaucoma and mydriasis.
  • Glaucoma:
    • Condition: Optic nerve damage due to fluid buildup and elevated intraocular pressure.
    • Risk: Left untreated can permanently impair vision.
  • Mydriasis:
    • Definition: Pupil dilation that does not respond to light; also called fixed pupil.
  • Real-world relevance: Essential for treating eye infections, glaucoma management, and ocular procedures.

VERTIGO, MOTION SICKNESS & VOMITING

  • Vertigo: Illusion of self or environment motion.
  • Motion sickness: Illness related to travel (e.g., seasickness, car sickness).
  • Vomiting: Can be associated with vertigo or motion sickness; often a symptom of an underlying cause.
  • Real-world relevance: Affects quality of life and safety; management includes antiemetic strategies.

ANTIEMETICS

  • Definition: Drugs effective against vomiting and nausea.
  • Uses: Treat vertigo and motion sickness; can be administered in multiple forms.
  • Routes of administration:
    • Tablets
    • Sublingual
    • Oral solutions
    • Suppositories
    • Transdermal patches
    • Intravenous injections
  • Real-world relevance: Widely used in clinical settings for nausea/vomiting prevention and treatment across various conditions and procedures.