Medication (drug therapy)
Drug Therapy depends on the complaints of the symptoms presented by the patient and associated psychiatric conditions.
There is a notorious comorbidity between generalized anxiety disorder and major depression. They are so common that psychiatrists often advice the medical students that if they see GAD to look again, and they will probably find major depression.
According to Martin Keller, MD, chief of psychiatry, Brown University Program in Medicine, Providence, R.I., 14% of patients whose GAD is accompanied by major depression have attempted suicide at least once. Even in those who were not diagnosed with depression, 11% have attempted suicide, he noted (JAMA 1989;262:2654). Clinically, Dr. Keller said the percentage of patients whose GAD is being treated with benzodiazepines, tricyclic antidepressants, anxiolytics and selective serotonin reuptake inhibitors has not changed markedly since 1989. Unfortunately, he commented, patients
are more likely to be treated with subclinical doses of whatever medication their physician prescribes.
According to many psychiatrists, benzodiazepines have not fulfilled their promise, although they are a great improvement over
barbiturates.
Here are some common drugs used in the treatment
of GAD.
Venlafaxine XR
Venlafaxine XR is effective as an antidepressant as well as for the treatment of GAD. It is the first antidepressant that is indicated for both depression and GAD. In clinical studies Venlafaxine XR was found to be more effective than buspirone in patients with GAD but without comorbid depression. In another study comparing venlafaxine XR with fluoxetine (Prozac) in patients with depression and comorbid anxiety venlafaxine XR showed a greater magnitude of effect in both depression and anxiety.
David Sheehan, MD, a professor of psychiatry at the University of South Florida (USF) College of Medicine, in Tampa, USA. is a great believer in venlafaxine. In the 1999 annual meeting of the European College of Neuropsychopharmacology, Dr. Sheehan said that venlafaxine (Effexor, Effexor XR, Wyeth-Ayerst) has been shown to lead to a mean 10-point improvement on the Hamilton Anxiety
Rating Scale (HAM-A) when taken at 75 mg/d, and a 12-point improvement when taken at 225 mg/d (Int Clin Psychopharmacol 1996;11:137-145). This compares with patients in the placebo group, who experienced an eight-point improvement.
Patients taking 225 mg/d showed a statistically significant improvement in six out of seven domains for the HAM-A. Even at 150 mg/d, patients showed a statistically significant improvement in two out of seven domains.
Clinical improvements were seen in the study group within the first one to two weeks, with only 28.2% relapsing by the 26-week mark. By contrast, those taking placebo only saw an improvement up to week 10, after which there was a loss of efficacy, with 52.3% relapsing by week 26 (P<0.001).
Buspirone (Buspar)
Typically administered in a dosage range of 20-60 mg/day, buspirone has been shown to be effective and safe in the treatment of GAD. It is however slow to take effect - usually there is a lag time of 3 to 4 weeks before it efficacy is achieved for GAD. This slow action may be a problem for people suffering from acute anxiety.
Buspirone is more effective than benzodiazepines for the psychic symptoms of GAD, such as apprehension and worry, as well as depressive symptoms. Buspirone is particularly useful in treating elderly patients who are more sensitive to benzodiazepine use. It is also given along with benzodiazepines where the combination is very effective.
Buspirone has the virtues of not being addicting, having minimal side effects, and not causing withdrawal symptoms. It also does not interact with alcohol. Side effects associated with buspirone include dizziness, headaches, and nausea.
Benzodiazepines
Benzodiazepines include:
Although these medications act rapidly and effectively and relieve panic attacks and general anxiety, they can be addictive, impair memory, and increase tiredness. When carefully used, however, these medications can be quite helpful for a short time. They often lose their effectiveness over the long term.
Benzodiazepines are useful in relieving somatic and autonomic symptoms more effectively than psychic symptoms of anxiety.
Benzodiazepines will not prevent depression from emerging and may even exacerbate or precipitate depression. Since anxiety is frequently found in association with several other psychiatric illnesses, most notably depression, the use of Benzodiazepines alone is limited. It is often used in combination with other drugs.
Nefazodone
Nefazodone is a newer antidepressant with anxiety reduction potential. In a small, 8-week trial of nefazodone in patients with GAD, 80% reported their symptoms as being at least "much improved." Common side effects of nefazodone included fatigue, drowsiness, headache, and insomnia. Overall, nefazodone was effective and well tolerated. The recommended dosage of 375 mg/day for treating GAD is similar to effective nefazodone doses used for treating depression. Although nefazodone has been proved effective as an antidepressant, its potential for the attainment and maintenance of remission in the long-term treatment of GAD needs further investigation.
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