Possible respiratory abnormalities in panic disorder.
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Anxiety Disorders↗
Biomedical subjects
A J Fyer
Publications and source records attributed to A J Fyer.
Phenelzine in social phobia.
Phenelzine was administered to 11 patients meeting DSM-III criteria for social phobia in open clinical trials. Seven of 11 showed marked improvement, while the remaining four experienced moderate benefit. These findings, which require replication in controlled trials, suggest that in addition to other actions, phenelzine has a direct effect in reducing interpersonal hypersensitivity.
Adolescent↗
Recent developments in the understanding and pharmacotherapy of panic attacks.
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Agoraphobia↗
Lactate provocation of panic attacks. II. Biochemical and physiological findings.
Thirty-one of 43 patients with panic disorder or agoraphobia with panic attacks and none of 20 normal controls panicked in response to infusions of sodium lactate. Before receiving lactate, patients showed higher heart rates than controls and also signs of hyperventilation. During lactate infusion, patients who did not panic, nevertheless, developed higher lactate and pyruvate levels and greater ionized calcium and pH changes than controls. Lactate-induced panic attacks were regularly accompanied by biological changes consistent with hyperventilation and central noradrenergic activation and irregularly by elevation of plasma norepinephrine and cortisol levels. Panic attacks were not associated with changes in epinephrine or calcium levels or pH. Baseline arousal increased the likelihood of panic during lactate infusion. It is hypothesized that lactate-induced panic primarily involves central noradrenergic discharge with inconsistent peripheral manifestations.
Adult↗
Social phobia. Review of a neglected anxiety disorder.
While other anxiety disorders have recently become the subjects of increasing investigation, social phobia remains, except among behavior therapists, relatively unstudied. As a result, major uncertainties exist concerning classification, prevalence, severity, etiology, assessment, and treatment of social phobia. Existing findings do suggest that in its own right and as a comparison for other anxiety disorders, social phobia should prove a fertile area for psychobiological and clinical investigation.
Adrenergic beta-Antagonists↗
Platelet monoamine oxidase activity in patients with panic disorder.
Preliminary reports have indicated that platelet monoamine oxidase (MAO) activity is elevated in patients with anxiety disorder. We compared MAO activity in 20 drug-free patients with panic disorder with 20 age- and sex-matched normal controls. MAO activity in patients was significantly higher than in normals. MAO activity was not correlated with age or plasma catecholamine levels. The authors speculate about the possible significance of elevated MAO activity in patients with panic disorder.
Adult↗
Lactate vulnerability of remitted panic patients.
Sodium lactate precipitates panic in 70-100% of clinically ill patients with panic disorders. The lactate vulnerability of remitted patients is unknown. In this study, 13 panic patients completed three sequential sodium lactate infusions: one before treatment, a second when panic free on tricyclic antidepressants (TCA), and a third when in remission and unmedicated for 1 to 6 months. Three out of 13 patients panicked at the third infusion as compared to 0/13 infused on TCA and 7/12 at pretreatment infusion. This result (1) indicates that lactate vulnerability can exist in clinically well, unmedicated patients, and (2) raises the possibility that lactate vulnerability may be a trait characteristic. Further studies are needed before definite conclusions can be drawn.
Adult↗
Normalization of venous pH, pCO2, and bicarbonate levels after blockade of panic attacks.
Recent evidence suggests that hyperventilation may be associated with spontaneous panic attacks in patients with panic disorder. This is reflected in abnormal patterns of blood gas and blood pH levels in these patients. In this study, absolute levels and variances of pH, pCO2, and bicarbonate were compared between controlled patients before and after successful pharmacological treatment. The results indicate that successful treatment of panic disorder results in a normalization of pH, pCO2, and bicarbonate levels.
Adult↗
Treatment of social phobia with atenolol.
Social phobia is the least well studied phobic disorder of those included in DSM-III. Reports from the British literature indicate that the condition is a distinct one that usually begins in adolescence and affects males more often than females. Patients characteristically complain of somatic symptoms and a fear of humiliation when confronted with specific social stimuli. Ten social phobic patients were openly treated with the cardioselective, peripherally active beta-adrenergic blocking drug atenolol. Five patients had complete response and four had moderate response. Side effects were minimal. Atenolol appears to work in social phobic patients by reducing autonomic nervous system response to phobic stimuli.
Adult↗
Lactate infusions in obsessive-compulsive disorder.
Panic attacks followed sodium lactate infusions in one of seven patients with obsessive-compulsive disorder and 26 of 48 patients with panic disorder or agoraphobia with panic attacks. This suggests that lactate-induced panic is specific to the latter groups.
Adult↗
Specificity of lactate infusions in social phobia versus panic disorders.
Lactate infusions produced panic attacks in one of 15 patients with social phobia, four of nine with agoraphobia, and 10 of 20 with panic disorder in a blind study. The proportion of patients with social phobia who panicked in response to lactate was significantly lower than that of patients with agoraphobia or panic disorder. These findings lend validity to the DSM-III classification of anxiety states. They also suggest that the pathophysiology of social phobia differs from that of disorders characterized by spontaneous panic attacks.
Adult↗
Lactate provocation of panic attacks. I. Clinical and behavioral findings.
To assess the pharmacologic and phenomenologic comparability of lactate-induced and naturally occurring panic attacks, patients meeting DSM-III criteria for panic disorder or agoraphobia with panic attacks were infused with 0.5M racemic sodium lactate before and after successful drug treatment. Lactate-induced and naturally occurring panic attacks were symptomatically similar. Following treatment, the patients' response to lactate did not differ from that of normal controls, whereas the pretreatment panic rate was much higher. These data suggest that lactate acts, by as yet unidentified mechanisms, to trigger the same panic attacks as occur spontaneously in vulnerable persons.
Adult↗
Hypoglycemia and panic attacks.
Many patients with panic disorder believe hypoglycemia causes their symptoms. Of 10 patients with panic disorder given sodium lactate to induce panic, none had evidence of low blood sugar levels when they began to experience anxiety symptoms.
Adolescent↗
Insulin levels during lactate infusion.
To determine whether the lactate-induced panic of patients with panic attacks results from hyperinsulinism balanced by epinephrine-enhanced gluconeogenesis, the authors measured 10 subjects' insulin levels exactly when the lactate-induced attacks began. The insulin levels were normal.
Adult↗
Response to hyperventilation in a group of patients with panic disorder.
Twelve patients with DSM-III diagnoses of panic disorder and four normal volunteers were studied during hyperventilation of room air and increased ventilation stimulated by 5% CO2. Patients also underwent sodium lactate infusion. Eight of the patients had a panic attack during sodium lactate infusion, seven during CO2 inhalation, and three during room-air hyperventilation. Since CO2 increases the firing of the locus ceruleus, and since sodium lactate infusion is known to increase cerebral CO2, these findings are consistent with other evidence implicating the locus ceruleus in panic anxiety.
Adult↗
Effects of naloxone on patients with panic attacks.
To determine whether endogenous opiates are involved in panic anxiety, the authors challenged 12 patients with panic attacks with intravenous naloxone hydrochloride alone or combined with sodium lactate. Naloxone did not produce panic attacks or alter responses to lactate.
Adult↗
Sodium lactate infusion, panic attacks, and ionized calcium.
The ability of sodium lactate to precipitate panic attacks in vulnerable individuals has been repeatedly demonstrated, although its mechanism of action is unknown. Pitts and McClure hypothesized that the panicogenic effect of sodium lactate was due to its induction of a peripheral hypocalcemia via the complexing of infused lactate ions with extracellular ionized calcium. In the current study, serial ionized calcium measurements during lactate infusion are assessed for 22 panic patients who panicked during infusion, 11 panic patients who did not panic during the procedure, and 6 normal controls. Intravenous sodium lactate infusion was found to be associated with a significant decrease in ionized calcium in all groups. No specific association was found between the rate or magnitude of decrease in ionized calcium and the occurrence of a panic attack during the infusion.
Agoraphobia↗