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Benzodiazepines
Benzodiazepines
are drugs that relieve anxiety by acting on the limbic system, an area deep
inside the brain that appears to be involved in primitive emotional responses. Benzodiazepines
work at the level of the nerve cells in the brain. They enhance the effects of a
chemical messenger called gamma aminobutyric acid (GABA) that slows down the
activity of the nerve cell. When GABA binds to the nerve cell, a channel is
widened allowing more chloride ions to move into the nerve cell. This makes the
cell less active. When benzodiazepines bind to GABA receptors, the effects are
enhanced.
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Benzodiazepines
enhance the sedating effect of GABA by allowing chloride ions (Cl-)
into the nerve cells, slowing the activity of the neuron.
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Benzodiazepines,
including alprazolam (Xanax, Parmacia and Upjohn), diazepam (Valium, Roche) and
lorazepam (Ativan, American Home Products), are usually taken orally. They take
effect rapidly, and have few bothersome side effects. These can include
agitation, worsened anxiety, confusion, impaired memory, lack of coordination,
speech difficulties, and others. However,
some patients, especially those who have had problems with alcohol or drug
dependency, may become dependent on benzodiazepines. Some of the symptoms
patients can experience if they stop taking benzodiazepines too quickly include
blurred vision, decreased concentration, decreased mental clarity, diarrhea,
heightened awareness of noise or bright light, loss of appetite and weight, and
seizures. Reducing the dose gradually generally minimizes these problems.
Another
problem is that the combination of these drugs with sedatives, including
alcohol, is potentially lethal. In general, the abuse of anti-anxiety drugs
costs society millions of dollars in drug rehabilitation and other medical
expenses. As a result, several states closely monitor or restrict the
prescribing of dependence-causing anti-anxiety drugs. For this reason, intensive
research is ongoing to develop non-drug therapies aimed at reducing stress and
to discover anti-anxiety drugs that are non-addicting.
To
counter these problems, doctors try to prescribe the shorter acting
benzodiazepine compounds because they are less likely to cause prolonged side
effects. In the older population, oxazepam is the selected agent because it does
not accumulate in the body as much as other benzodiazepines. The shorter acting
benzodiazepines are also associated with a decreased risk for hip fractures and
falls in the elderly population.
In
patients where sedation or potential addiction are problems, clinicians may
prescribe BuSpar (buspirone, Bristol Myers Squibb). This anti-anxiety drug is
not a benzodiazepine, however, it is an effective anti-anxiety agent that is not
addictive, and can be taken for extended periods of time. It is also less likely
to make patients feel drowsy. However, BuSpar needs to be taken for at least
seven days before improvement, and it may take three to four weeks before
maximum effect occurs. The most common side effects are dizziness, nausea,
headache, fatigue, nervousness, light-headedness and excitement Drugs in the class
Diazepam (Valium)
Alprazolam Extended-Release (Xanax XR)
Alprazolam tablets (Niravam, Xanax)
Clorazepate (Tranxene, Tranxene T, Tranxene-SD)
Oxazepam (Serax)
Alprazolam Oral Solution (Alprazolam Intensol)
Chlordiazepoxide (Libritabs, Librium)
Lorazepam (Ativan)
Clonazepam (Klonopin) |
