What does anterograde amnesia mean and which drugs can cause this effect?

Anterograde amnesia - reduced ability of a patient to remember new information or occurring events during the time the drug is effective. Benzodiazepines drugs such as Triazolam, Temazepam, Lorazepam and Midazolam cause this effect.

Name the effects of the sedative-hypnotic drugs on the normal sleep pattern and explain their significance to the patient.

• Decrease in the time it takes to fall asleep.
• Decrease in the duration of REM sleep.
• Increase duration of NREM phase.
• Decrease duration of phase 4 NREM.
• Ultimately increase the sleep duration.

Significance - to help patients who suffer from insomnia to fall asleep and increase the quality of sleep.

Which of the sedative-hypnotic drugs are used as a supplementary therapy in anaesthesia?  Can you explain why?

Diazepam, lorazepam and especially midazolam.

This is due to their anterograde amnesiac effects, sedation and anti-anxiolytic effects.

Which of the sedative-hypnotic drugs are used as anticonvulsants?

• Diazepam
• Lorazepam
• Clonazepam
• Clobazam
• Phenobarbitone
• Primidone.

What is the mechanism of the muscle-relaxing effects of some of the carbamates and the BDs?

The mechanism of action is the binding of the drug to the α-γ subunit of the GABA receptor, thus potentiating GABA's effects, this includes prolonged hyperpolarisation (relaxation of smooth muscle).

Discuss the effects of the sedative-hypnotic drugs on the respiratory and cardiovascular systems.

Effects are more noticeable when drugs are given via IV.

• Most sedative-hypnotic drugs: Decrease breathing and heart rate during phase 4 NREM
• Buspirone: Chest pain, tachycardia
• Thiopental: Hypotension, respiratory depression and apnoea, laryngeal and bronchial spasms
• Antihistamines: Tachycardia
• Propranolol: Bradycardia, bronchospasm
• Flumazenil: Cardiac arrhythmias