Sedation and Hypnosis
- Representative Drugs: Benzodiazepines (diazepam), barbiturates (phenobarbital).
- Mechanism: Enhances the effect of γ-aminobutyric acid (GABA), an inhibitory neurotransmitter, suppresses cortical excitability, relieves anxiety, and induces sleep.
- Clinical Use: Treats insomnia, anxiety disorders, and preoperative sedation.
Antiepileptic and Anticonvulsant Effects
- Representative Drugs: Sodium valproate, carbamazepine, levetiracetam.
- Mechanism: Controls epileptic seizures by inhibiting abnormal neuronal discharges (e.g., blocking sodium channels) or enhancing GABAergic transmission.
- Clinical Use: Various epilepsies (e.g., tonic-clonic seizures, absence seizures) and febrile convulsions.
Analgesia, Antipyretic, and Anti-Inflammatory Effects
- Representative Drugs:
- Opioids (morphine, fentanyl);
- Non-steroidal anti-inflammatory drugs (NSAIDs, e.g., ibuprofen).
- Mechanism:
- Opioids: Activate central opioid receptors to inhibit pain transmission;
- NSAIDs: Inhibit prostaglandin synthesis to reduce pain and inflammation.
- Clinical Use: Postoperative pain, cancer pain, and chronic pain (e.g., arthritis).
Antidepressant and Anxiolytic Effects
- Representative Drugs:
- Antidepressants: Selective serotonin reuptake inhibitors (SSRIs, e.g., fluoxetine), norepinephrine reuptake inhibitors (e.g., venlafaxine);
- Anxiolytics: Buspirone, benzodiazepines.
- Mechanism: Regulates central monoamine neurotransmitters (serotonin, norepinephrine) to improve mood regulation.
- Clinical Use: Depression, anxiety disorders, obsessive-compulsive disorder.
Antipsychotic Effects
- Representative Drugs: First-generation antipsychotics (chlorpromazine), second-generation (risperidone, olanzapine).
- Mechanism: Block central dopamine D2 receptors to alleviate positive symptoms (hallucinations, delusions); some drugs also act on serotonin receptors for negative symptoms.
- Clinical Use: Schizophrenia, acute mania in bipolar disorder.
Central Muscle Relaxation
- Representative Drugs: Baclofen, tizanidine.
- Mechanism: Inhibits spinal reflex hyperexcitability to relieve skeletal muscle spasm (e.g., blocks glutamatergic transmission).
- Clinical Use: Spasticity from multiple sclerosis, spinal cord injury, etc.
Cognitive Enhancement
- Representative Drugs: Cholinesterase inhibitors (donepezil), NMDA receptor antagonists (memantine).
- Mechanism:
- Donepezil: Inhibits acetylcholine degradation to enhance cognitive neurotransmission;
- Memantine: Regulates glutamate activity to protect neurons.
- Clinical Use: Cognitive impairments like Alzheimer's disease and vascular dementia.
Central Antitussive Effect
- Representative Drugs: Codeine, dextromethorphan.
- Mechanism: Suppresses the medullary cough center to block the cough reflex arc.
- Clinical Use: Non-productive cough (e.g., severe cough from colds, bronchitis).
Central Nervous System Stimulation
- Representative Drugs: Methylphenidate (for ADHD), caffeine.
- Mechanism: Promotes dopamine and norepinephrine release to enhance cortical alertness.
- Clinical Use: ADHD, narcolepsy, and countering central depression (e.g., sedative overdose).
Anesthesia and Anesthetic Adjuvant Effects
- Representative Drugs:
- General anesthetics: Propofol, sevoflurane;
- Anesthetic adjuvants: Midazolam, fentanyl.
- Mechanism: Inhibits CNS excitability to induce loss of consciousness, analgesia, and muscle relaxation.
- Clinical Use: Surgical anesthesia and sedation for endoscopic procedures.
Supplementary Notes:
- CNS drugs act with high selectivity, targeting molecular mechanisms like neurotransmitter receptors, ion channels, and enzymes.
- Some drugs have multiple functions (e.g., sodium valproate for epilepsy and mania), requiring precise indication-based use.
- Long-term use may involve dependence, tolerance, or neurotoxicity, necessitating strict adherence to clinical guidelines.