Pfizer Inc's sertraline hydrochloride (HCl) demonstrated better tolerability and better maintained clinical improvements during dose tapering periods compared to paroxetine HCl in the treatment of panic disorder. These data will be presented at the Anxiety Disorders Association of America (ADAA) 23rd National Conference.

Results of a multi-center, randomized, double-blind, 15-week study with 225 patients, treated with either sertraline HCl or paroxetine HCl demonstrated comparable efficacy in the treatment of panic disorder during the 12-week treatment phase. However, during the following three-week, dose tapering phase, the efficacy of sertraline HCl was maintained whereas patients given paroxetine HCl showed significant clinical worsening and a greater number of withdrawal symptoms when compared to sertraline HCl.

“These findings suggest that patients taking sertraline HCl will maintain response, while patients on paroxetine HCl will have more panic attacks and show overall worsening during the dose tapering and discontinuation process,” said Borwin Bandelow, M.D., Professor of Psychiatry, University of Goettingen, Germany, and lead investigator of the study. “Accordingly, these findings are important considerations for physicians making treatment decisions about panic disorder.”

In the study, outpatients diagnosed with panic disorder (based on DSM-IV criteria) were randomized to 12-weeks of treatment with sertraline HCl (titrated up to 50-150 mg; N=112) or paroxetine HCl (titrated up to 40-60 mg; N=113). Dosing was then tapered over three weeks. The primary efficacy measure was the Panic and Agoraphobia Scale (PAS), a five-point frequency and intensity rating of 13 items on five panic disorder dimensions. Secondary measures included panic attack frequency; and the Clinical Global Impression Improvement scale, which measures the physician's assessment of a patient's improvement (CGI-I < 2 were responders).

During the three-week dose tapering period, the PAS scores were maintained at their treatment-period level in the sertraline HCl group (insignificant change of -2 per cent), but worsened by 25 per cent in the paroxetine HCl group (p < 0.05 versus sertraline HCl at week 15). Similarly, during this same period, the percent of participants who remained free of panic attacks increased from 54 per cent to 58 per cent in the sertraline HCl group, but decreased from 53 per cent to 42 per cent in the paroxetine HCl group (p < 0.05 versus sertraline HCl at week 15).

Overall patients given sertraline HCl also reported fewer side effects and a lower incidence of clinically significant weight gain (> seven percent of total body weight) compared to those taking paroxetine HCl (p < 0.05 seven percent vs. one percent).

Panic disorder is an anxiety disorder that consists of recurrent, unexpected panic attacks accompanied by at least one month or more of persistent concern about having another attack, worrying about the implications of having an attack, or significant behavioral changes related to the attack.

Sertraline HCl is indicated for a wide range of mood and anxiety disorders: depression, premenstrual dysphoric disorder (PMDD), posttraumatic stress disorder (PTSD), panic disorder (with or without agoraphobia), adult and pediatric obsessive-compulsive disorder (OCD) and social anxiety disorder. Sertraline HCl is approved for the long-term treatment of PTSD, OCD and panic disorder in adults. It is the only medication approved for the long-term treatment of PTSD and social anxiety disorder.

Sertraline HCl is the most prescribed brand of its kind in the United States and is available in 96 countries around the world. Since its approval more than a decade ago, millions of people have been treated with sertraline HCl.

Patients who are taking monoamine oxidase inhibitors (MAOIs) or pimozide should not take sertraline HCl.

The most common side effects of sertraline HCl include upset stomach, trouble sleeping, diarrhea, dry mouth, sexual side effects, feeling sleepy or tired, tremor, indigestion, sweating, feeling agitated and having less appetite.

On average, in eight-week controlled trials, patients treated with sertraline HCl experienced a minimal one-to-two pound weight loss. Discontinuation due to weight loss is rare in patients treated with sertraline HCl. Significant weight loss may be an undesirable result of treatment with sertraline HCl for some patients.