أدوية الجهاز العصبي 4
#Pharmacology_of_CNS 4
#CNS
#Anxiolytic_and_Hypnotic_Drugs
مواضيعنا الليلة حا تكون👇
✔️BENZODIAZEPINES
✔️BENZODIAZEPINE ANTAGONIST
✔️OTHER ANXIOLYTIC AGENTS
💠Anxiety is an unpleasant state of tension, apprehension, or uneasiness(a fear that arises from either a known or an unknown source).
💠Because many antianxiety drugs also cause some sedation, they may be used clinically as both anxiolytic and hypnotic (sleepinducing)agents.
✔️ BENZODIAZEPINES
💠Benzodiazepines are widely used anxiolytic drugs
بنجد انو حلت لينا مكان الbarbiturates (حا نتكلم عنها البوست الجاي ان شاء الله) لانها بتعتبر safer and more effective
🔵 Mechanism of action
🔹The targets for benzodiazepine actions are the γ-aminobutyric acid
(GABAA) receptors
🔹GABA is the major inhibitory neurotransmitter in the central nervous system (CNS).
بتعمل الكلام عن طريق فتح بوابات الكلور وبكدا لما يدخل الكلور حا يحصل decreases للneurotransmission by inhibiting the formation of action potentials
🔹The GABAA receptors are composed of a combination of five α, β, and γ subunits
بس نتذكر انو في اختلاف في مكان ارتباط ال GABA وال benzodiazepine
🔹Benzodiazepines increase
the frequency of channel openings produced by GABA.
🔵Actions
🔷Reduction of anxiety
🔷Sedative/hypnotic
All benzodiazepines have sedative and calming properties, and some can produce hypnosis
🔷Anterograde amnesia
🔷Anticonvulsant
🔷Muscle relaxant
Baclofen is a muscle relaxant that is believed to affect GABA receptors at the level of the spinal cord.
🔵Therapeutic uses
🔷Anxiety disorders
〰Benzodiazepines are effective for the treatment of the anxiety symptoms secondary to panic disorder, generalized anxiety disorder (GAD), social anxiety disorder, performance anxiety, posttraumatic stress disorder, obsessive–compulsive disorder,and extreme anxiety associated with phobias, such as fear of flying.
The benzodiazepines are also useful in treating anxiety related to depression and schizophrenia
〰The longer-acting agents, such as clonazepam, lorazepam and diazepam, are often preferred in those patients with anxiety that may require prolonged treatment.
〰For panic disorders, alprazolam is effective for short- and long-term treatment
〰 The antianxiety effects of the
benzodiazepines are less subject to tolerance than the sedative and
hypnotic effects
⚠️Note
Tolerance that is, decreased responsiveness to repeated doses of the drug
يعني بتقل فعالية الدواء بتكرار الجرعات فبالتالى لازم نزيد الجرعة ودا بدخلنا في خطر ال toxicity
〰Cross-tolerance exists between the benzodiazepines and
ethanol
🔷Sleep disorders
〰Commonly prescribed benzodiazepines for sleep disorders include:
▪️short-acting
triazolam
▪️intermediate-acting
temazepam
estazolam
▪️Long-acting
flurazepam
quazepam
🌀temazepam is useful for insomnia caused by the inability to stay asleep
🌀triazolam is effective in treating individuals who have difficulty in going to sleep.Tolerance frequently develops within a few days
🌀In general, hypnotics should be given for only a limited time,
usually less than 2 to 4 weeks
🔷Amnesia
〰Midazolam is a benzodiazepine used to facilitate amnesia while causing sedation prior to anesthesia
🔷Seizures
〰Clonazepam is occasionally used as an adjunctive therapy for certain types of seizures, whereas lorazepam and diazepam
are the drugs of choice in terminating status epilepticus
〰Due to cross-tolerance, chlordiazepoxide, clorazepate, diazepam,lorazepam, and
oxazepam are useful in the acute treatment of alcohol withdrawal
🔷Muscular disorders
〰Diazepam is useful in the treatment of skeletal muscle spasms
🔵Pharmacokinetics
🔹The benzodiazepines are lipophilic.They are rapidly and completely absorbed after oral administration, distribute throughout the body and penetrate into the CNS.
🔹The half-lives of the benzodiazepines are important clinically, because the duration of action may determine the therapeutic usefulness.The benzodiazepines can be roughly divided into short-, intermediate-, and long-acting group
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