Anxiety disorders medication dosing

Another study with citalopram evaluated its efficacy in the treatment of social anxiety disorder along with co-morbid major depression (Schneier etal., 2003). The outpatients (n= 21) were predominantly Hispanic (76%) and from New York. Response rates for the intent-to-treat sample were 66.7% for social anxiety disorder and 76.2% for major depression. Only one subject was known to have withdrawn secondary to severe side effects. The mean dose of the medication was 37.6 mg/day and there was no placebo control. The depressive symptoms tended to improve... 

Patients with panic disorder should be seen every 2 weeks during the first few weeks to adjust medication doses based on symptom improvement and to monitor side effects. Once stabilized, they can be seen every 2 months. The Hamilton Rating Scale for Anxiety (score less than or equal to 7 to 10) can be used to measure anxiety, and the Sheehan Disability Scale (with a goal of less than or equal to 1 on each item) can be used to measure for disability. During drug discontinuation, the frequency of appointments should be increased. 

Substance-Induced Anxiety Disorder. Numerous medicines and drugs of abuse can produce panic attacks. Panic attacks can be triggered by central nervous system stimulants such as cocaine, methamphetamine, caffeine, over-the-counter herbal stimulants such as ephedra, or any of the medications commonly used to treat narcolepsy and ADHD, including psychostimulants and modafinil. Thyroid supplementation with thyroxine (Synthroid) or triiodothyronine (Cytomel) can rarely produce panic attacks. Abrupt withdrawal from central nervous system depressants such as alcohol, barbiturates, and benzodiazepines can cause panic attacks as well. This can be especially problematic with short-acting benzodiazepines such as alprazolam (Xanax), which is an effective treatment for panic disorder but which has been associated with between dose withdrawal symptoms. 

Specific Sociai Anxiety Disorder, Acute Phase Treatment. Different strategies have evolved for treating specific social anxiety disorder versus generalized social anxiety disorder. Less complicated is the management of the specific subtype. Exposure-based psychotherapy is a mainstay of treatment, and as-needed medication doses prior to scheduled performances are also widely used. Preferred agents for performance anxiety are alprazolam or propranolol. 

Avoidant Personality Disorder (APD). We generally recommend following the same pharmacological treatments for APD that are nsed for the generalized subtype of social anxiety disorder. Because APD is so pervasive, medications should be used on a daily basis as opposed to as-needed dosing. 

Available pharmacokinetic (PK) studies of medications with potential to treat pediatric anxiety disorders have been open studies that examine PK parameters and monitor adverse effects in children and adolescents. None of the pediatric PK studies described below were designed as dose finding studies, and none of the studies were able to describe a clear association between dose or exposure and specific adverse effect. However, pediatric PK data can be useful to guide dosing and adverse effect monitoring to the extent that the weight-adjusted PK parameters inform extrapolation based on comparable studies of adult PK. The following summary of PK studies is based on multiple-dose PK studies. 

The commonly used classes of antidepressants are discussed in the following sections, and information about doses and half-lives is summarized in Table 2-1. The antidepressant classes are based on similarity of receptor effects and side effects. All are effective against depression when administered in therapeutic doses. The choice of antidepressant medication is based on the patient s psychiatric symptoms, his or her history of treatment response, family members history of response, medication side-effect profiles, and comorbid disorders (Tables 2-2 and 2-3). In general, SSRIs and the other newer antidepressants are better tolerated and safer than TCAs and MAOIs, although many patients benefit from treatment with these older drugs. In the following sections, clinically relevant information is presented for the antidepressant medication classes individually, and the pharmacological treatment of depression is also discussed. The use of antidepressants to treat anxiety disorders is addressed in Chapter 3. 

In this chapter, we discuss the pharmacology of medications that are classified as anxiolytic, sedative, or hypnotic—primarily the benzodiazepines, buspirone, zolpidem, eszopiclone, and zale-plon. Subsequently, we present diagnosis-specific treatment guidelines (outlined in Table 3-1). The commonly used anxiolytics and hypnotics, together with their usual doses, are shown in Table 3-2. Many antidepressant medications are also effective in the treatment of anxiety disorders. The pharmacology of antidepressants is discussed in Chapter 2 their clinical use in anxiety disorders is addressed in the diagnosis-specific sections later in this chapter. 

The duration of pharmacotherapy for generalized anxiety disorder is controversial. Psychotherapy is recommended for most patients with this disorder, and it may facilitate the tapering of doses of medication. However, generalized anxiety is often a chronic condition, and some patients require long-term pharmacotherapy. As in other anxiety disorders, the need for ongoing treatment should be reassessed every 6-12 months. 

Uhlenhuth EH, Balter MB, Ban TA, et al. International study of expert judgment on therapeutic use of benzodiazepines and other psychotherapeutic medications IV. Therapeutic dose dependence and abuse liability of benzodiazepines in the long-term treatment of anxiety disorders. J Clin Psychopharmacol 1999 19(suppl 2) 23S-29S. 

The key features of each anxiety disorder are given below, with a practical description of the preferred choice of medication, its dose and duration. 

Advances in pharmacotherapy in the past decade have provided clinicians with many safe and effective medications for the treatment of patients with OCD. The SSRIs and clomipramine (an SRI) are the first-line pharmacological therapies for patients with OCD. The treatment of OCD patients with SSRIs is unique in that a selective efficacy exists (other non-SRI antidepressants are ineffective in OCD), a longer therapeutic lag occurs, and higher doses are often required than in treating patients with major depression or other anxiety disorders. The SSRIs provide clinically significant relief in up to 70% of OCD patients, although most do not reach full remission. Clinical experience with the SSRIs suggests that they alleviate the symptoms of OCD, but they do not cure the illness. No one SSRI has been demonstrated to be superior to the others in head-to-head trials. 

Some psychiatric medications also produce a response within minutes of taking a single dose. Their therapeutic benefit can come very quickly. For example, taking a benzodiazepine such as diazepam (Valium) can quickly relieve panic and anxiety. Taking a stimulant can often rapidly relieve the symptoms of attention deficit-hyperactivity disorder (ADHD). When psychiatric medications work this quickly, we assume that the therapeutic benefit is a direct consequence of their initiating action in the synapse. 

Although all patients with depression should undergo a thorough medical evaluation, no specific tests are required before SSRI therapy is initiated. The usual starting doses of SSRIs are summarized in Table 2-1. These standard doses should be decreased by 50% in patients with hepatic disease and in elderly persons. In addition, patients with panic disorder or significant anxiety symptoms are often intolerant of the initial stimulating side effects that commonly occur with SSRI use. In these cases, the initial dose should be decreased... 

In some cases, anxiolytics serve a transitional purpose. For example, for a patient with acute-onset panic disorder, severe anticipatory anxiety, and a family history of depression, administration of an antidepressant medication that also has antipanic effects may be the optimal treatment, but this will not help the patient for several weeks, during which time there is a risk of progression to agoraphobia. For this patient, starting antidepressant therapy and also attempting to obtain acute symptom relief with a benzodiazepine may be helpful. After 4 weeks, the benzodiazepine dose should be slowly tapered so that the patient s condition is controlled with the antidepressant alone. 

Treatment guidelines for depression and anxiety increasingly emphasize the value of longer-term maintenance treatment with antidepressants in order to prevent recurrence of illness. It is therefore important to assess the adverse effects burden of longer-term medication. The change in adverse effects profile over 1 year of treatment has been studied in a double-blind, placebo-controlled study of maintenance treatment with imipramine (average daily dose 160 mg) in 53 patients with panic disorder (15). Adverse effects of imipramine, such as sweating, dry mouth, and increased heart rate, persisted over the year... 

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