Anti-anxiety/Hypnotic (Benzodiazepines).

Question 1

Classification:

Answer 1

1- Long acting:
Diazepam, flurazepam, quazepam, chlordiazepoxide, clorazepate.

2- Intermediate acting:
Alprazolam, estazolam, lorazepam, temazepam.

3- Short acting:
Oxazepam, triazolam.

Question 2

Mechanism of action:

Answer 2

• Bindes to GABAa receptor.
• Opening chloride channels→cl- entry..
• Hyperpolarization.
• Increase the affinity of GABA to its receptor.

Question 3

Pharmacokinetics:

Answer 3

1- Absorption & distribution:
- Lipophilic, rapidly and completely absorbed after oral administration.

• distribute throughout the body & penetrate into the CNS.

2- Metabolism:
- Metabolised in liver to produce active products (chlordiazepoxide, diazepam).

• After metabolism these are conjugated & excreted via kidney.

Question 4

Actions:

Answer 4

1- Reduction of anxiety: (Alpha2-GABA receptor)
At low doses: inhibiting neuronal circuits in the limbic system.

2- Sedative/ Hypnotic: (Alpha1-GABA receptor)
(The hypnosis is in high dose).

3- Anterograde amnesia: (Alpha1-GABA receptor)
(فقدان ذاكرة مؤقت يجي مع استخدام العقار هذا، أخرى عدم القدرة على تكوين ذكريات جديدة).

4- Anticonvulsant: (Alpha1-GABA receptor).

5- Muscle relaxant: (Alpha2-GABA receptor).
in large dose.
(Baclofen: ms relaxant, affect GABA R at level of the spinal cord).

Question 5

Therapeutic uses:

Answer 5

1- Anxiolytic (in panic disorders).

2- Insomnia (Triazolam).

3- Anticonvulsant (clonazepam, lorazepam & diazepam).

4- Preanesthetic medication (amnesia).

5- Muscle spasm (Diazepam).

6- Alcohol withdrawal symptoms.

Question 6

Adverse effects:

Answer 6

1- Drowsiness & confusion.

2- Cognitive impairment.

3- Ataxia. (اضطراب التوازن)

4- Triazolam: dose dependent change in sleep pattern: ↑REM & ↓NREM & tolerance.

5- Impairment of mental & motor functions.

6- Rebound insomnia.

7- Hypotension & respiratory depression.

8- Dependence & abuse.