Anxiety disorders treatment

Generalized Sociai Anxiety Disorder, Treatment Resistance. A significant minority of patients will not experience a satisfactory treatment response to antidepressant therapy, even after a trial of adequate duration at full strength doses. For those with comorbid depression who are experiencing no benefit from SSRI treatment for either the anxiety or depression, then switching treatment is advisable. The options include switching to another SSRI, a SNRI (venlafaxine or perhaps dulox-etine), or, when other alternatives fail, phenelzine. 

Of the three disorders that make up Cluster C, only APD has received much attention in medication treatment studies. In addition, much of this has been an extraction of the results of social anxiety disorder treatment studies. 

SramekJJ, Zarotsky V, Cutler NR. Generalised anxiety disorder treatment options. Drugs. 2002 62 1635-1648. 

For chronic anxiety disorders, treatment most often reduces or even eliminates symptoms, but not a cure since symptoms can recur after medicine stopped... 

Benzodiazepines, ie, the hiU BZR agonists, are prescribed for anxiety, insomnia, sedation, myorelaxation, and as anticonvulsants (97). Those benzodiazepines most commonly prescribed for the treatment of anxiety disorders are lorazepam (19), alprazolam (20), diazepam (21), bromazepam (22), chlorazepate (23), and oxazepam (24). These dmgs together represent about 70% of total... 

Antidepressants are small heterocyclic molecules entering the circulation after oral administration and passing the blood-brain barrier to bind at numerous specific sites in the brain. They are used for treatment of depression, panic disorders, generalized anxiety disorder, social phobia, obsessive compulsive disorder, and other psychiatric disorders and nonpsychiatric states. 

Anxiolytics are drugs used for the treatment of anxiety disorders. Apart from benzodiazpines, a frequently used anxiolytic is the 5HT1A (serotonin) receptor agonist buspiron, which has no sedative, amnestic or muscle-relaxant side effects, but whose action takes about a week to develop. Furthermore, it is less efficaceous than the benzodiazepines. Buspiron s mechanism of action is not fully understood. 

Benzodiazepines are amongst the most frequently prescribed drugs they have well-established uses in the treatment of anxiety disorders (anxiolytics) and insomnia, preanaesthetic sedation, suppression of seizures, and muscle relaxation. 

The definition of desired therapeutic and side effects in the case of the benzodiazepines very much depends on the clinical problem in question. The sedative and hypnotic actions are desired effects in the treatment of insomnia, but undesired effects in the treatment of anxiety disorders. Effects that are usually undesired include daytime drowsiness, potentiation of the sedative effects of ethanol, and anterograde amnesia. They are mediated via the benzodiazepine site of GABAa receptors, since they can be antagonized with flumazenil. 

Indeed, 5-HT is also a substrate for the 5-HT transporter, itself an important player in the treatment of depression, and more recently for the whole range of anxiety disorders spectrum (GAD, OCD, social and other phobias, panic and post-traumatic stress disorders). It is the target for SSRIs (selective serotonin reuptake inhibitors) such as fluoxetine, paroxetine, fluvoxamine, and citalopram or the more recent dual reuptake inhibitors (for 5-HT and noradrenaline, also known as SNRIs) such as venlafaxine. Currently, there are efforts to develop triple uptake inhibitors (5-HT, NE, and DA). Further combinations are possible, e.g. SB-649915, a combined 5-HTia, 5-HT1b, 5-HT1d inhibitor/selective serotonin reuptake inhibitor (SSRI), is investigated for the treatment of major depressive disorder. 

Tranquilizers (also called antianxiety drugs) are used to treat a variety of psychiatric disorders which go along with anxiety (anxiety disorders). Serotonin-reuptake inhibitors and the benzodiazepines are the most commonly employed drugs for the treatment of common clinical anxiety disorders. 

Antianxiety drugp are used in the management of anxiety disorders and short-term treatment of the symptoms of anxiety. Long-term use of these dru is usually not recommended because prolonged therapy can result in drug dependence and serious withdrawal symptoms. 

Anxiety disorders are common in the population of opioid-addicted individuals however, treatment studies are lacking. It is uncertain whether the frequency of anxiety disorders contributes to high rates of illicit use of benzodiazepines, which is common in methadone maintenance programs (Ross and Darke 2000). Increased toxicity has been observed when benzodiazepines are co-administered with some opioids (Borron et al. 2002 Caplehorn and Drummer 2002). Although there is an interesting report of clonazepam maintenance treatment for methadone maintenance patients who abuse benzodiazepines, further studies are needed (Bleich et al. 2002). Unfortunately, buspirone, which has low abuse liability, was not effective in an anxiety treatment study in opioid-dependent subjects (McRae et al. 2004). Current clinical practice is to prescribe SSRIs or other antidepressants that have antianxiety actions for these patients. Carefully controlled benzodiazepine prescribing is advocated by some practitioners. 

Lejoyeux et al. 1998). Similar to opioid-dependent persons, these patients reported that they use benzodiazepines to self-medicate anxiety, insomnia, and alcohol withdrawal and, less commonly, to enhance the effects of ethanol. Approximately l6%-25% of patients presenting for treatment of anxiety disorders abuse alcohol (Kushner et al. 1990 Otto et al. 1992). Controversy exists concerning appropriate benzodiazepine prescribing in this population (Cir-aulo and Nace 2000 Posternak and Mueller 2001). 

Further detailed analyses of the ECA data have been extrapolated to USA national costs (Rice and Miller, 1998). It was calculated that the economic costs of mental disorders in 1990 in the USA totalled US 147.8 billion. Anxiety disorders were the most cosdy, amounting to 46.6 billion, just under a third of the total. Direct costs spent on mental health care totalled 67 billion, of which anxiety disorders accounted for only 11 billion (16.5%). Drug costs were 2191 million, of which anxiety disorders accounted for 1167 million—over half Morbidity costs—the value of goods and services not produced because of mental disorders — amounted to 63.1 billion, with anxiety disorders accounting for 34.2 billion, 54.2% of the total. This reflects the high prevalence of anxiety disorders in the community and the high associated rate of lost productivity. In contrast, patients with affective disorders appeared better able to function (Rice and Miller, 1995). In summary, anxiety disorders are common, disruptive and costly to society drug treatment is a substantial element of treatment costs (11%) compared with, say, schizophrenia (2.2%). 

Extrapolation to other countries is not easy. Canada has a very different health-care system to the USA. A small-scale study involving 466 anxiety disorder patients in Quebec established a clear relationship between the severity of the disorder and utilization of health services (McCusker et al, 1997). Patients with obsessive-compulsive disorder were particularly likely to seek treatment. No information on dmg use was presented. 

Out-patient treatment is substantially cheaper than in-patient management and is generally as effective (Lowman, 1991). A French study on patients with generalized anxiety disorder estimated costs per patient over 3 months to he US 423 for hospitalization, 335 for out-patient services and 43 for medications (Souetre et al, 1994). Comorbid conditions (mostly alcoholism and depression) doubled these direct health-care costs. Over three-quarters of all patients were taking anxiolytic medication. 

Generalized anxiety disorder has been relatively neglected from the point of view of both health economics and pharmacoeconomics. The changing diagnostic criteria have made it difficult to compare data over time, leading researchers to focus on the more clearly defined disorders such as panic and obsessions. Drug treatment has been dominated by the benzodiazepines, usually available genetically and cheaply. However, as the final section of this chapter will show, all this is in flux. 

In the wider medicopolitical arena, the health cost of the anxiety disorders more than justifies pleas to accord their treatment greater prominence in health policy and research funding (Rupp et al, 1998). 

Pigott TA (1999). Gender differences in the epidemiology and treatment of anxiety disorders./Clin Psychiatry 60 (suppl. 18),... 

Figure 19.8 A schematic representation of the GABAa receptor shift hypothesis. This proposes that patients with panic disorder have dysfunctional GABAa receptors such that the actions of drugs that behave as antagonists in normal subjects are expressed as inverse agonism in panic patients. It is unlikely that this theory extends to generalised anxiety disorder (GAD), for which benzodiazepine agonists are highly effective treatments, but it could explain why these drugs are relatively ineffective at treating panic disorder. (Based on Nutt et al. 1990)...

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