History Repeats Itself: Pharmacodynamic Trends in the Treatment of Anxiety Disorders

Treatment of anxiety in patients with coronary heart disease: Rationale and design of the UNderstanding the benefits of exercise and escitalopram in anxious patients WIth coroNary heart Disease (UNWIND) randomized clinical trial

BACKGROUND

Anxiety is highly prevalent among patients with coronary heart disease (CHD), and there is growing evidence that high levels of anxiety are associated with worse prognosis. However, few studies have evaluated the efficacy of treating anxiety in CHD patients for reducing symptoms and improving clinical outcomes. Exercise and selective serotonin reuptake inhibitors have been shown to be effective in treating patients with depression, but have not been studied in cardiac patients with high anxiety.

METHODS

The UNWIND trial is a randomized clinical trial of patients with CHD who are at increased risk for adverse events because of comorbid anxiety. One hundred fifty participants with CHD and elevated anxiety symptoms and/or with a diagnosed anxiety disorder will be randomly assigned to 12 weeks of aerobic exercise (3×/wk, 35 min, 70%-85% VO2peak), escitalopram (5-20 mg qd), or placebo. Before and after 12 weeks of treatment, participants will undergo assessments of anxiety symptoms and CHD biomarkers of risk, including measures of inflammation, lipids, hemoglobin A1c, heart rate variability, and vascular endothelial function. Primary outcomes include post-intervention effects on symptoms of anxiety and CHD biomarkers. Secondary outcomes include clinical outcomes (cardiovascular hospitalizations and all-cause death) and measures of quality of life.

CONCLUSIONS

The UNWIND trial (ClinicalTrials.gov NCT02516332) will evaluate the efficacy of aerobic exercise and escitalopram for improving anxiety symptoms and reducing risk for adverse clinical events in anxious CHD patients.

Possible involvement of GABAergic and nitriergic systems for antianxiety-like activity of piperine in unstressed and stressed mice

BACKGROUND

An investigation was made to explore the possibility of anxiolytic activity of piperine in unstressed and stressed mice along with the underlying role of nitriergic and GABAergic modulation for the noted activity of piperine.

METHODS

Piperine (5, 10 and 20mg/kg, ip) was administered to unstressed mice. In another groups of animals, piperine was administered 30 min before subjecting them to immobilization stress for 6h. Antianxiety activity was evaluated by employing elevated plus maze, light-dark box and social interaction test. Diazepam was employed as standard anxiolytic drug.

RESULTS

Piperine produced significant antianxiety-like activity in unstressed and stressed mice. The anxiolytic-like activity of piperine was comparable to diazepam. In unstressed mice, piperine significantly increased brain GABA levels, but could not produce any change in plasma nitrite levels. Meanwhile, in stressed mice, piperine did not produce any significant change in GABA levels, but significantly decreased nitrite levels. Pre-treatment with aminoguanidine (50mg/kg, ip), an inducible nitric oxide synthase (NOS) inhibitor, significantly potentiated the anxiolytic-like activity of piperine, as compared to piperine and aminoguanidine alone in stressed mice. On the other hand, pretreatment with 7-nitroindazole (20mg/kg, ip), a neuronal NOS inhibitor significantly potentiated the antianxiety-like activity of piperine, as compared to piperine and 7-nitroindazole alone in unstressed mice.

CONCLUSION

These data suggest that the piperine produced significant anxiolytic activity in unstressed mice possibly through increase in GABA levels and inhibition of neuronal NOS. On the other hand, antianxiety activity in stressed mice might be through inhibition of inducible NOS.

1-(2-Cyclohex-2-enylpropionyl)-3-methylurea, 2-ethyl-5-methylhexanamide and 2-ethylpentanamide: three products of barbiturate decomposition

The three title compounds were obtained by reactions which mimic, with more extreme conditions, the in vivo metabolism of barbiturates. 1-(2-Cyclohex-2-enylpropionyl)-3-methylurea, C(11)H(18)N(2)O(2), (I), and 2-ethylpentanamide, C(8)H(17)NO, (III), both crystallize with two unique molecules in the asymmetric unit; in the case of (III), one unique molecule exhibits whole-molecule disorder. 2-Ethyl-5-methylhexanamide, C(9)H(19)NO, (II), crystallizes as a fully ordered molecule with Z' = 1. In the crystal structures, three different hydrogen-bonding motifs are observed: in (I) a combination of R(2)(2)(4) and R(2)(2)(8) motifs, and in (II) and (III) a combination of R(4)(2)(8) and R(2)(2)(8) motifs. In all three structures, one-dimensional ribbons are formed by N-H···O hydrogen-bonding interactions.

Involvement of NO-cGMP pathway in anti-anxiety effect of aminoguanidine in stressed mice

In the present study, effect of aminoguanidine (12.5, 25 and 50mg/kg, i.p.), a selective inhibitor of inducible nitric oxide synthase, was evaluated for its anti-anxiety activity in stressed mice employing elevated plus maze, open field test, light/dark test and social interaction test. Restraint stress induced by immobilizing for 6h enhanced an anxiety-like behavior and increased plasma nitrite levels in mice. Only the highest dose (50mg/kg) employed of aminoguanidine attenuated the stress-induced anxiety-like behavior and decreased plasma nitrite levels. There was no significant anxiolytic effect of aminoguanidine in unstressed mice. Sildenafil (1mg/kg i.p.), was used to explore the probable mechanism of anti-anxiety activity of aminoguanidine through NO-cGMP signaling. Aminoguanidine (50mg/kg) attenuated the anxiogenic effect of sildenafil. Aminoguanidine and sildenafil per se and in combination did not affect the locomotor activity of stressed and unstressed mice as compared to their respective control groups. Thus, aminoguanidine produced anti-anxiety activity in stressed mice through iNOS-NO-cGMP pathway.

Tiagabine in anxiety disorders

GABA has been implicated in both the aetiology and treatment of anxiety. Tiagabine is currently the only selective GABA reuptake inhibitor available in US markets; it exerts its action via GAT-1 transporter blockade presynaptically, facilitating GABA neurotransmission. Preclinical studies and current human studies suggest tiagabine possesses anxiolytic properties. The anxiolytic properties of tiagabine have also been suggested in a number of case series, open-label studies and placebo-controlled studies in patients with different anxiety disorders. Throughout these studies, tiagabine has been reasonably tolerated; the most commonly reported adverse events include dizziness, headache and nausea. Tiagabine may be a useful addition to currently available drugs for anxiety; however, the data from small open-label investigations remain to be confirmed in larger controlled studies.