All drugs ending in "zepam" or "zolam" are benzodiazepines.  Benzodiazepines are used in anxiety, sleep, seizure disorders.  They are both sedative-hypnotics and anxiolytics.  They are also used in the detoxification and treatment of alcohol withdrawl.

They are CNS depressants.

Benzodiazepines are lipid soluble and stored in the CNS.  They have a wide therapeutic index! (therapeutic dose is much lower than the toxic dose).  Some benzodiazepines are extensively plasma protein bound (diazepam 99%), while others are barely bound (flurazepam 4%).

Benzos differ in their speed of onset, half life, and duration of active metabolites.

Benzodiazepines are metabolized by both phase1 and phase2 reactions in the liver.  Recall that phase1 involved redox and hydrolysis.  Phase2 involves conjugations such as glucoronidation; conjugations occur in the cytosol. 

Phase1 reactions use the microsomal (CYP450) enzymes of the SER to produce important active intermediates from the benzodiazepines Chlordiazepoxide, diazepam, and flurazepam.  This means that the action of these drugs is extended well beyond the half life of the parent drug!

The omega-1 benzo receptor is responsible for the hypnotic effects of the drugs.

Recall omega-2 produces their anxiolytic effects.  Omega-3 produces their myelorelaxant effects.

Benzodiazepines are CNS depressants and should therefore be withheld if further CNS depression will cause harm..  Such would be the case in patients with sleep apnea, in which the drug induced furthering of muscle relaxation will only worsen the ventilatory response to CO2. (remember that benzos have myelorelaxant properties by acting at the omega-3 benzo receptor site)

Diazepam and other benzos should be AVOIDED IN PREGNANCY.  They are risk factor D drugs and may cause cleft lip/palate.

Benzodiazepines should NOT be taken concurrently with other CNS depressants like opioids, barbiturates, or alcohol.

Buspirone is a non-benzo, non-barb that is used in GAD.  It is not useful in severe cases like panic attack, or severe anxiety because it has a delayed onset of action.  It really takes about a week for buspirone's anianxiety effects to kick in.

BUSpirone is used in GAD, where people are afraid of everything, including being runover by a BUS.

The Big Z drugs are a set of non-benzos, non-barbs.  They are Zolpidem, Zaleplon (and Zopiclone).  Zolpidem and Zaleplon are available in the US.  They are fast acting hypnotics used to treat initial insomnia.  As they are hypnotics, this means they act at the omega-1 receptor of the GABAa channel.

In fact, they are specific for this omega-1 site, so they exert only a hypnotic effect, unlike benzodiazepines, which can act at omega 1, 2, and 3 sites.

Zolpidem is one of the Big Z drugs.  It is a non-benzo, non-barb and acts on the benzodiazepine-omega-1 site. It is therefore a pure-hypnotic.  Recall: omega1=hypnotic effect, omega2= anxiolytic effect, omega3= myelorelaxant effects.

Due to its hypnotic effects, it is used to treat insomnia.  Specifically, because of its fast onset of action, it treats initial insomnia.

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Chloral hydrate is used for sedating children and the elderly. 

It is a prodrug that is converted into the active metabolite trichloroethanol.  At high doses, this is metabolized to trichloracetic acid, which accumulates and interferes with the acid-base balance.  It is hardly ever used anymore due to the side effects.

Temazepam and triazolam are useful for transient insomnia.

They are also useful in cases of initial insomnia, with a peak plasma concentration reached in about 30 minutes.  Triazolam's half life is much less than temazepam, the later of which may have some carry-over sedation.

Oxazepam and Lorazepam have intermediate-length half-lives.    They are therefore useful for "sleep maintenance" insomnia, in which the patient can get to sleep but has difficulty staying asleep.  

(Flurazepam could also be used, but only if daytime drowsiness is acceptable.  It's half-life is very long, so the patient will experience morning sedation.)

While temazepam has a long half life, it's peak plasma concentration is reached very early and so it is not as good as Oxazepam or Lorazepam, whose plasma peaks are reached in 1-3 hours.

The elderly have a higher lipid/water ratio.  Because benzodiazepines are lipid soluble, this translates into a larger compartment to store the drug in.  This means the drugs remain in the system of the elderly longer.  Give drugs that have an appropriate half-life but NO active intermediate that will further prolong the activity of the drug... the drug's activity is already prolonged by the increased lipid/water ratio!

Useful drugs would be Oxazepam, lorazepam, and temazepam.  These three drugs undergo phase 2 metabolism without undergoing phase 1... they do not have active intermediates and do not accumulate with chronic dosing!  this is perfect for the elderly. 

(remember: diazepam, flurazepam, and chlordiazepoxide all have active intermetiates)

Oxazepam and lorazepam are benzodiazepines with intermediate-length half-lives.  They are useful in the treatment of sleep-maintenance insomnia. 

Remember: Oxazepam and lorazepam are also useful drugs in treating the elderly, who have a higher lipid/water ratio and therefore require special consideration with these lipid-soluble drugs!

To treat insomnia, you want to use a drug with a short-intermediate half life so that it can exert its effect over the night, but not interfere with the patient once they wake up. 

Not only does diazepam have a long half-life, it is also metabolized to an active intermediate, further extending its duration of action!  The patient would feel a hangover effect and potentially amnesia...

This carryover sedation and amnesia may be beneficial in patients that have had an operation etc.  But not for the normal everyday patient.

In generalized anxiety disorder, the patient is anxious 24 hours a day.  Therefore, you need to choose a drug with an intermediate-to-long half life, that will cover their waking hours!

A good choice is Diazepam.  Also consider Buspirone. 

As with most anxiety disorders, SSRIs have also found some use.

Because the patient is always stressed, you need a drug with an intermediate-to-long half life that will calm him all day. 

Consider the benzodiazepines Alprazolam, Diazepam, Oxazepam, Lorazepam, and Clonazepam

Clonazepam is the most potent antiepileptic of the benzodiazepines.

Othe drugs used as anticonvulsants are diazepam and Lorazepam
(These drugs are used in the treatment of status epilepticus)

Diazepam, lorazepam, and clonazepam are used as myelorelaxants.  (these are the same drugs used in anticonvulsive therapy)

This means that they exert an influence at the omega-3 site of the benzodiazepine receptor.

Buspirone is a non-benzo non-barb anxiolytic used to treat generalized anxiety disorder (GAD).

Bupropion is an antidepressant used in patients that have failed to respond to TCADs.  It blocks the reuptake of DA.  It is also used to treat nicotine withdrawal.

BUSpirone for patients that fear getting runover by a BUS.

BuPROPione for depressed patients that need to be "PROPPED up" / keep their mood up