Therapeutic response to benzodiazepine in panic disorder subtypes

Abstract

Clonazepam was equally effective in the treatment of the respiratory and non-respiratory subtypes of panic disorder, suggesting there is no difference in the therapeutic response between the two subtypes.

Psychopharmacotherapy of panic disorder: 8-week randomized trial with clonazepam and paroxetine

“…The present investigation confirms earlier studies, which have demonstrated the efficacy of clonazepam (11,12,21,(28)(29)(30) and paroxetine (18,19,31,32) in separate trials in the treatment of panic disorder. The present study compares clonazepam with paroxetine using a parallel methodology with the same team of health providers.…”

“…remain symptomatic and this proportion may be higher in the naturalistic setting (9). In addition, the subtype of panic disorder (respiratory or non-respiratory) can influence the response to pharmacotherapy and affect outcomes (10)(11)(12). Furthermore, discontinuation of pharmacotherapy can lead to withdrawal symptoms and a significant number of panic disorder patients suffer relapse flowing cessation of treatment (13,14).…”

Panic Disorder Respiratory Subtype: Psychopathology, Laboratory Challenge Tests, and Response to Treatment

“…The RS patients improved faster than the non-RS patients, and in week 8 there was a statistically significant difference in the outcome measures; nevertheless, at week 52 both groups had improved equally. 20 In a six-week treatment study, 75 patients who received clonazepam improved significantly more than those who received placebo. Between the RS and the non-RS patients who received the active drug, no significant differences were found, 75 though this result may reflect the small sample size.…”

Clonazepam in the treatment of psychiatric disorders: an update

“…Response rates: clonazepam/sertraline 41% versus placebo/sertraline 4% (week 1); clonazepam/ sertraline 63% versus placebo/sertraline 32% (week 3); (P r 0.05) Pollack et al (2003) 60 R, DB, PC 12-week study: paroxetine (titrated to 40 mg/day by week 4) + placebo or clonazepam for 5 weeks [mean dose titrated to 1.6 mg/day by week 5] and then discontinued [3-week taper] or continued for 7 weeks Remission at endpoint: clonazepam/paroxetine (with tapered clonazepam discontinuation) 50% versus clonazepam/paroxetine (with ongoing treatment) 20% versus clonazepam/placebo 18% Clonazepam/paroxetine displayed earlier onset of response with significant advantage in the PD Severity Scale from weeks 1-5 versus placebo/ paroxetine (P < 0.05); no additional benefit in maintaining benzodiazepine after week 5 Jacobs et al (1997) 144 R, DB, PC 6-week regimen of clonazepam (titrated to 4 mg/day by week 3; dose maintained for 3 weeks) (followed by r 6-week tapered withdrawal) SF-36 Mental Health Component Summary scale mean improvement: clonazepam improved score by 8.9 versus 3.9 with placebo (P = 0.03) Clonazepam also improved work productivity versus placebo Nardi et al (2000) 22 R, DB, PC Single dose clonazepam 2 mg % Patients with a CO 2 challenge-induced panic attack: after single-dose clonazepam 2 mg 18% had a mild attack versus 82% of placebo recipients with moderate-severe attack Valenca et al (2002b) 34 DB, PC Placebo before CO 2 challenge then clonazepam 2 mg/day for 6 weeks OR clonazepam 2 mg before CO 2 challenege then placebo for 6 weeks % Patients with a CO 2 challenge-induced panic attack: 21%, 6% and 11% with clonazepam versus 80%, 75% and 67% with placebo after acute dosing and 2 and 6 weeks of treatment, respectively Wulsin et al (1999) 27 R, DB, PC 4-week flexible dose (1-4 mg/day) then 2-week taper Response rates at 4 weeks: HAM-A total scores r 50% of baseline score: clonazepam 58% versus placebo 14% (P = 0.038); weekly panic attack frequency 0% or 50% decrease from baseline: clonazepam 67% versus placebo 47% (P = 0.44) Valenca et al (2003) 34 R, PC Clonazepam 2 mg/day for 6 weeks % Patients panic-free at endpoint: clonazepam 78% versus placebo 8% (P < 0.001) Panic attack remission and reduction in anxiety and was equally effective in respiratory and non-respiratory subtypes Non-placebo-controlled studies Worthington et al (1998) Nardi et al (2005) 67 Open, UC Clonazepam 1-4 mg/d for 3 years % Patients panic-free at endpoint: > 95% of patients with respiratory and non-respiratory PD subtypes were free of panic attacks after 3 years Respiratory subgroup had a faster response at 8 weeks and equivalent response in follow-up period Valenca et al (2002a) 14 Open, UC Clonazepam 2 mg/day for 6 weeks % Patients with a CO 2 challenge-induced panic attack: of those who had a panic attack after CO 2 challenge at baseline 14% had a panic attack after CO 2 challenge after 6 weeks of clonazepam treatment Nardi et al (1999) Clonazepam (n = 10, mean dose 2.7 mg/ day) or alprazolam (n = 3; mean 2.5 mg/day) continued for 1-6 months Clonazepam reduced physiological expression of arousal but failed to show a beneficial effect on the course of PTSD 13 control Patients meeting PTSD diagnostic criteria 6 months after trauma: 69% (n = 9) of benzodiazepine patients versus 15% (n = 2) of controls …”

“…respiratory and non-respiratory) and studies have tried to associate different subtypes with different responses to treatments (Briggs et al, 1993). Clonazepam 2 mg/day for 6 weeks was significantly superior to placebo in panic attack remission and reduction in anxiety in a study of 34 PD patients; clonazepam was equally effective in respiratory and non-respiratory subtypes (Valenca et al, 2003).…”