Alprazolam extended-release in panic disorder.
Alprazolam-XR is an extended-release formulation of alprazolam designed to deliver sustained therapeutic concentrations for 24 h after once-daily dosing. Plasma concentrations gradually decline as the time for the next dose approaches, but still remain above therapeutic minimum levels. The anti-panic efficacy of alprazolam-XR appears to be comparable to the original formulation of alprazolam. The main advantage of the new extended-release formulation appears to be its greater tolerability and safety. The speed with which high-potency benzodiazepines are absorbed, and rise to peak concentrations is correlated with both abuse potential and with the incidence and severity of common adverse events, such as sedation and cognitive and psychomotor impairment. Alprazolam-XR does not exhibit the sudden increases in plasma concentration characteristic of the original formulation of alprazolam. This pharmacokinetic difference appears to translate into a reduced liability of abuse and a reduced incidence of sedation and cognitive and psychomotor impairment during acute therapy. This would appear to give alprazolam-XR a more favourable benefit:risk profile than the original formulation of alprazolam. In addition, the once-daily dosing (as opposed to three or four times per day) reduces clock-watching, increases compliance and it eliminates the penalty of breakthrough anxiety and panic that many patients experience if they inadvertently miss a dose. It should be noted that long-term therapy with alprazolam-XR carries the same risk of dependence and withdrawal during discontinuation as the original formulation of alprazolam.
Rickels
Karl
K
University of Pennsylvania, Department of Psychiatry, University of Pennsylvania Medical Center, PA 19104-3309, USA. krickels@mail.med.upenn.edu
D000525:Alprazolam / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D018592:Cross-Over Studies; D003692:Delayed-Action Preparations / Q000494:pharmacology / Q000627:therapeutic use*; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D006801:Humans; D016584:Panic Disorder / Q000188:drug therapy* / Q000453:epidemiology / Q000503:physiopathology; D013375:Substance Withdrawal Syndrome; D013607:Tablets
D003692:Delayed-Action Preparations; D013607:Tablets; D000525:Alprazolam