Benzodiazepines
Benzodiazepines are primarily anxiolytics, but do have sedative effects in man and sick animals. They also cause muscle relaxation and are anticonvulsants.
Mechanism of Action
GABA is an inhibitory neurotransmitter that opens post-synaptic Cl- channel to hyperpolarise the membrane and reduce the chance of action potential conduction occuring. Benzodiazepines modulate the GABA/Cl- channel complexes to enhance the effects of GABA. Benzodiazepines therefore have no intrinsic activity.
Side Effects and Contraindications
Benzodiazepines give mild respiratory and cardiovascular suppression. They are however synergistic with central depressants such as barbiturates, antihistamines and alcohol.