Anxiolytics

Anxiolytics/Hypnotics/Sedatives Benzodiazepines Trichloroethanol derivatives Barbiturates Chlormethiazole

Benzodiazepines Potentiates the effects of GABA Metabloised in the liver

Benzodiazepines- actions Hypnotic Sedative anxiolytic anticonvulsant muscle relaxant

Clinical indications for the use of Benzodiazepines Anxiety states/panic attacks Insomnia Alcohol/Drug withdrawal states night terrors, somnambulism in children muscle spasms Epilepsy Anaesthesia and sedation for minor surgical procedures-endoscopies

Problems associated with the use of benzodiazepines tolerance amnesia dependence Overdose

Adverse effects Drowsiness lightheadedness amnesia impaired psychomotor function( driving or operating machinery) addiction

Interactions additive effect with other CNS depressants

Benzodiazepines in pregnancy Regarded unsafe in pregnancy Diazepam is teratogenic in mice. Benzodiazepines cross the placenta poor suckling in the new born

Examples of benzodiazepines in commom clinical use Diazepam t1/2 30hr Chlordiazepoxide 20 Temazepam 13 Midazolam 3

Benzodiazepine antagonists Flumazenil(anexate) Clinically useful in the reversal of the effects of benzodiazepines after endoscopies ect Self poisonig

Chloral hydrate induces sleep in 1/2 an hr and lasts 6-8 hrs with little hang over irritant to stomach used in children

Chlormethiazole Has hypnotic sedative and anticonvulsant properties Frequently used in the management of alcohol withdrawal also used in senile psychosis and confusion

Barbiturates Obsolete as hypnotics and sedatives low therapeutic index Physical dependence occurs

Insomnia Treat the cause eg Depression No currently available drug induces normal sleep Benzodiazepines are the first choice As they alter the sleep pattern least Relatively safe in over dosage A drug with shorter t 1/2 and inactive metabolites are preferred eg temazepam

Anxiety Benzodiazepines preferred A drug with long halflife preferred Should not be used for more than 4 weeks Beta blockers have a role to play