Citalopram Alprazolam

A larger set of placebo-controlled studies show conclusively that imipramine is also effective for the treatment of panic disorders. Other agents shown to be effective in panic disorders include the SSRIs paroxetine, sertraline, fluvoxamine, fluoxetine and citalopram. Generally, initial treatment of moderate to severe panic disorders may require the initiation of a short course of benzodiazepines e.g. clonazepam (0.5 1 mg twice daily), and an SSRI. The patient will obtain immediate relief from panic attacks with the benzodiazepine whereas the SSRI may take 1 6 weeks to become effective. Once a patient is relieved of initial panic attacks, clonazepam should be tapered and discontinued over several weeks and SSRI therapy continued thereafter. There are no pharmacological treatments available for specific phobias, however controlled trials have shown efficacy for several agents, e.g. phenelzine, moclobemide. clonazepam, alprazolam, fluvoxamine. sertraline and paroxetine in the treatment of social phobia (Roy-Byrne and Cowlev, 2002). 

Hall J, Naranjo CA, Sproule BA, et al. Pharmacokinetic and pharmacodynamic evaluation of the inhibition of alprazolam by citalopram and fluoxetine. J Clin Psychopharmacol 2003 23 349-357. 

The effects of SSRIs on alprazolam pharmacokinetics have been studied in 21 healthy volunteers (age and sex not given) who were pre-treated with either fluoxetine or citalopram (20 mg/day for 21 days) (98). Fluoxetine increased the AUC of a single 1.0 mg dose of alprazolam by 32% citalopram had no effect. These findings are consistent with previous reports that fluoxetine and its active metabolite, norfluoxetine, produce moderate inhibition of CYP3A4 while citalopram does not. 

A 30-year-old man with a history of major depression and panic disorder had been in remission for a year with citalopram 20 mg/day, valproate 600 mg/day, and alprazolam 3 mg/day (23). The citalopram was tapered over 3 weeks to 5 mg/day and then withdrawn. The day after the last dose he experienced anxiety and irritability together with frequent short-lasting bursts of dizziness, not having had the latter previously panic and depression did not recur and after a week the symptoms resolved spontaneously. 

A within-subject, double-bhnd, placebo-controlled, parallel design has been used to measure the effects of citalo-pram (20 mg/day) and fluoxetine (20 mg/day) on the pharmacokinetics and pharmacodynamics of alprazolam (1 mg/day) (45). Fluoxetine significantly impaired the metabolism of a single oral dose of alprazolam 1 mg, leading to prolongation of the half-life and an increased AUC, whereas citalopram did not. Neither SSRI significantly affected the pharmacodynamic effects of alprazolam. This experiment suggests differential effects of citalopram and fluoxetine on alprazolam kinetics. 

Other agents Clonazepam (C) Alprazolam (A) Lorazepam (L) Paroxetine (P) Sertraline (S) Citalopram (C) ... 

A general study in psychiatric patients found that when data on benzodiazepines was pooled, they caused a modest 23% increase in serum citalopram levels, which is almost certainly too small to be clinically relevant. Alprazolam was the only benzodiazepine to cause an elevation of citalopram levels (by 13%) when analysed alone. In another study, citalopram was found to have no effect on alprazolam plasma levels, although the time to maximum alprazolam concentration was increased by 30 minutes. Similarly, a study in 17 healthy subjects found no pharmacokinetic interaction between triazolam and citalopram, and it was suggested that triazolam and other substrates of the cytochrome P450 isoenzyme CYP3A4 are unlikely to have pharmacokinetic interactions with citalopram. ... 

Thieme, D. Sachs, H. Improved screening capabilities in forensic toxicology by application of liquid chromatography-tandem mass spectrometry, Anal.ChimActa, 2003, 492, 171-186. [hair LC-MS alprazolam dothiepin piritramide cocaine lorazepam lormetazepam clonazepam flimitrazepam bromazepam midazolam flurazepam nitrazepam temazepam medazepam nordazepam diazepam methylclonazepam triazolam oxazepam haloperidol benperidol sulpiride amisulpride mirtazapine citalopram olanzapine paroxetine fluoxetine sertraline zopiclone zolpidem risperidone quetiapine fentanyl pipamperone meperidine buprenorphine propoxyphene pentazocine phenazocine EDDP ... 

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