A comparison of lactate and isoproterenol anxiety states.

Both sodium lactate and isoproterenol can produce anxiety symptoms in patients with panic attacks. We administered both substances intravenously under placebo-controlled, double-blind conditions to patients with panic attacks and normal control subjects. We measured changes in anxiety levels using the Hamilton Anxiety Scale, State-Trait Anxiety Inventory, and a Panic Severity Scale. Measurements of respiratory rate and blood pH, pO2, pCO2, HCO3, and base excess were used to determine the relationship of hyperventilation to the symptoms induced by the infusions. Heart rate, epinephrine and norepinephrine levels were measured to determine whether there are changes related to palpitations and chest pain. Finger temperature and galvanic skin response were monitored to see whether any changes correlate with subject reports of hot or cold flashes and sweating. In this presentation, we will describe the clinical and biochemical changes that occur during panic attacks.