The effects of midazolam and ephedrine on post-exercise autonomic chronotropic control of the heart in normal subjects

Antipsychotic pharmacotherapy and orthostatic hypotension: identification and management

Orthostatic hypotension is a common adverse effect of antipsychotics that may delay or prevent titration to a dose necessary to control psychotic symptoms. Complications of orthostatic hypotension include syncope, transient ischaemic attack, stroke, myocardial infarction and death. The risk of orthostatic hypotension associated with antipsychotic therapy is increased in patients with disorders of the autonomic nervous system, fluid imbalance and those taking concomitant drug therapy that affects haemodynamic tone. Prospective monitoring for changes in postural blood pressure is important because patients with psychotic disorders often do not articulate symptoms of orthostasis and the subjective report of dizziness does not correlate well with orthostatic blood pressure changes. Nonpharmacological strategies and patient education, most notably, slowly rising from the supine position, are crucial first steps in the prevention and treatment of both symptomatic and asymptomatic orthostatic hypotension. Pharmacological treatment is only recommended when symptomatic orthostatic hypotension persists despite proper nonpharmacological therapy and there is a compelling indication for antipsychotic treatment. Fludrocortisone is a reasonable first choice for symptomatic orthostatic hypotension. Other agents including desmopressin and midodrine may be considered in patients who do not respond favourably to a trial of fludrocortisone, but safety concerns and lack of evidence limit the utility of these agents.

Anticipatory anxiety in moderately to highly-anxious oral surgery patients as a screening model for anxiolytics: evaluation of alprazolam

Alprazolam, a benzodiazepine anxiolytic, was evaluated in anxious patients prior to oral surgery. This population represents a possible acute screening model for novel anxiolytic agents. Healthy subjects, preselected for a moderate to high degree of dental anxiety based upon Corah's Dental Anxiety Scale, were enrolled in a three-arm parallel design study and randomly assigned to receive double-blind placebo (N=15), alprazolam 0.25 mg (N=16) or alprazolam 1 mg (N=16). Subjective self-reported anxiety was rated using the State Anxiety Inventory and visual analog scales. Objective measures included galvanic skin conductance, heart rate variability, blood pressure, pulse rate, and respiration. At 90 minutes after dosing, there were statistically significant (p<0.05) reductions compared with placebo in subjective anxiety and skin conductance mean level for the alprazolam-treated subjects. Changes from pre-dose (mean +/- SEM) at 90 minutes in the placebo, alprazolam 0.25 mg, and alprazolam 1 mg groups were -4.73 +/- 2.79, -13.75 +/- 2.49, and -12.81 +/- 2.32 for the State Anxiety Inventory and 5.44 +/- 6.71, -31.88 +/- 5.88, and -32.34 +/- 5.32 mm for analog anxiety scores. Corresponding skin conductance mean level at 100 minutes in the three groups (respectively) changed 0.64 +/- 0.24, -0.53 +/- 0.21, -0.71 +/- 0.22 microSiemens. The 0.25 mg and 1 mg dosages of alprazolam were not differentiated. Changes in heart rate variability, blood pressure, pulse rate, and respiration did not reflect subjective anxiety. Overall, the oral surgery anticipation anxiety model was found to be a sensitive test for benzodiazepine anxiolytic activity and may represent a potential screening model for evaluation of investigational agents.