Paroxetine Benzodiazepines

Generalized anxiety Duloxetine Escitalopram Paroxetine Venlafaxine XR Benzodiazepines Buspirone Imipramine Sertraline Hydroxyzine Pregabalin... 

Newer Generation Antidepressants. All SSRIs have been shown effective in the treatment of panic disorder. Of these, flnoxetine (Prozac), paroxetine (Paxil), and sertraline (Zoloft), as well as the SNRI venlafaxine ER (Effexor XR), have received FDA approval for the treatment of panic disorder. Because they are safer and easier to tolerate, SSRls/SNRls have largely supplanted the MAOIs and TCAs as standard treatments (along with benzodiazepines) for panic disorder. 

SSRls and SNRIs. The SSRl antidepressants, together with venlafaxine, have replaced the benzodiazepines as treatments of choice for GAD. Paroxetine and escitalopram are FDA approved for GAD, though it is generally believed that all SSRls and SNRIs are effective for GAD. Similar to the TCAs, SSRIs/SNRIs appear to be most effective for the intrapsychic symptoms of GAD but less effective than benzodiazepines for the somatic manifestations of the disorder. 

Lorazepam is a short-acting benzodiazepine indicated for use in relieving anxiety and insomnia. Lorazepam may also be administered perioperatively to alleviate pain and in status epilepticus. Imipramine is a tricyclic antidepressant, paroxetine is a selective serotonin re-uptake inhibitor, venlafaxine is a serotonin and adrenaline re-uptake inhibitor and moclobemide is a reversible monoamine oxidase inhibitor. Imipramine, paroxetine, venlafaxine and moclobemide are all classified as antidepressants. 

All SSRIs (e.g., Feonard et ah, 1997) and in particular fluoxetine, Fluvosamine and paroxetine are metabolized by hepatic cytochrome P450 enzymes. Therefore, it is important to be aware of the possibility that the therapeutic or toxic effects of other medications metabolized by the cytochrome P450 isoenzyme system can be increased. Substantial inhibition of these isoenzymes converts a normal metabolizer into a slow metabolizer with regard to this specific pathway. Inhibition of the hepatic oxidative isoenzymes has been associated with a reduction, to a varying extent, in the clearance of many therapeutic agents, including the TCAs, several neuroleptics, antiarrhythmics, theophy-lene, terfenadine, benzodiazepines, carbamazepine, and warfarin (for a complete list, see Nemeroff et ak, 1996). 

Several preliminary lines of research have started to suggest that antidepressants, once considered ineffective in generalized anxiety disorder, may be very efficacious [Gorman and Kent 1999]. In particular, venlafaxine has been effective in treating generalized anxiety disorder in both open-label and double-blind trials, and imipramine and paroxetine were as effective as a benzodiazepine in the long-term treatment of generalized anxiety disorder. 

Ballenger JG, McDonald S, Noyes R, et al The first double bhnd, placebo controlled trial of a partial benzodiazepine agonist abecarnil (ZK 112-119) in generalized anxiety disorder. Psychopharmacol Bull 27 171-179, 1991 Ballenger JG, Wheadon DE, Steiner M, et al Double-blind, fixed-dose, placebo-con-trolled study of paroxetin in the treatment of panic disorder. Am J Psychiatry 155 36-42, 1998... 

Generahzed anxiety disorder can be treated with benzodiazepines, buspirone, and certain antidepressants (e.g., venlafaxine, paroxetine, escitalopram). These agents are compared in Table 3-3. 

Drugs such as barbiturates and carbamazepine induce certain enzymes and will then trigger faster breakdown of some concomitantly used antipsycho-tics and antidepressants. In contrast, paroxetine, fluoxetine and fluvox-amine, acting by different mechanisms, inhibit the breakdown of other concomitantly administered drugs such as benzodiazepines, antidepressants, antiepileptics and neuroleptics (Table 5.1). 

Treatment of GAD can be undertaken using a number of pharmacological agents. Benzodiazepines have been found to be superior to placebo in several studies and all benzodiazepines appear to be equally effective. However, side effects include sedation, psvchomotor impairment, amnesia and tolerance (Chapter 1). Recent clinical data indicate that SSRIs and SNRIs are effective in the treatment of acute GAD symptoms. Venlafaxine, paroxetine and imipramine have been shown to be effective antianxiety medications in placebo-controlled studies. Case studies also indicate the usefulness of clomipramine, nefazodone, mirtazapine, fluoxetine and fluvoxamine in GAD. Buspirone, a 5-HTla receptor partial agonist, has been shown to be effective in several placebo-controlled, double-blind trials (Roy-Byme and Cowley, 2002). Buspirone has a later onset of action than both benzodiazepines and SSRIs but with the advantage of being non-addictive and non-sedating. 

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). 

Antidepressant drugs, however, might have direct anxiolytic effects. That is, certain antidepressants such as paroxetine (Paxil) or venlafaxine (Effexor) can help reduce anxiety independent of their effects on depression.1,47 These antidepressants have therefore been advocated as an alternative treatment for anxiety, especially for people who cannot tolerate the side effects of traditional anxiolytics, or who might be especially susceptible to the addictive properties of drugs like the benzodiazepines.1,9,46 Moreover, antidepressants such as paroxetine or venlafaxine are now considered effective as the primary treatment for several forms of anxiety, including generalized anxiety disorder, social phobia, and panic disorder.4,29,53 Antidepressants, either used alone or in combination with antianxiety drugs, have become an important component in the treatment of anxiety. 

Omeprazole, like cimetidine, can impair benzodiazepine metabolism and lead to adverse effects (SEDA-18, 43). Other drugs, including antibiotics (erythromycin, chloramphenicol, isoniazid), antifungal drugs (ketoconazole, itraconazole, and analogues), some SSRIs (fluoxetine, paroxetine), other antidepressants (nefazodone), protease inhibitors (saquinavir), opioids (fentanyl), calcium channel blockers (diltiazem, verapamil), and disulfiram also compete for hepatic oxidative pathways that metabolize most benzodiazepines, as well as zolpidem, zopiclone, and buspirone (SEDA-22,39) (SEDA-22,41). 

Treatment. The choice lies between a fast-acting benzodiazepine such as alprazolam (1-3 mg/day p.o.) and a drug with delayed efficacy but fewer problems of withdrawal such as a TCA, e.g. clomipramine (100-250 mg/day p.o.) or an SSRI, e.g. paroxetine (20-50 mg/day p.o.). The different time course of these two classes of agent in panic disorder is depicted in Fig. 19.5 (see also Tables 19.5 and 19.6). 

Treatment is poorly researched there have been few properly controlled trials and almost all open trials have been conducted on small numbers of patients long after the causative incident. The wide range of drugs that has been reported to provide some benefit includes benzodiazepines, TCAs and MAOIs paroxetine (SSRI) (20-50 mg/day p.o.) is now licenced for this indication in the UK. The preferred treattnent immediately following the... 

ASA = aspirin NSAIDs = non-steroidal anti-inflammatory drugs, such as ibuprofen, naproxen, and diclofenac CNS stimulants include drugs such as pseudoephedrine, dextroamphetamine, theophylline, and caffeine MAO = monoamine oxidase CNS depressants include drugs such as benzodiazepines, barbiturates, and ethanol SSRIs = selective serotonin reuptake inhibitors, such as fluoxetine, sertraline, and paroxetine. Antidiabetic agents include drugs such as insulin, glipizide, glyburide, and metformin. 

Clinically important, potentially hazardous interactions with alprazolam, aprepitant, astemizole, atorvastatin, benzodiazepines, carbamazepine, chlordiazepoxide, cilostazol, clonazepam, clorazepate, colchicine, conivaptan, cyclosporine, dabigatran, dasatinib, diazepam, digoxin, dihydroergotamine, disopyramide, ergot alkaloids, fesoterodine, fluoxetine, flurazepam, fluvastatin, HMG-CoA reductase inhibitors, imatinib, ixabepilone, lapatinib, lopinavir, lorazepam, lovastatin, methylprednisolone, methysergide, midazolam, nilotinib, oxazepam, paroxetine, pimozide, pravastatin, prednisone, quazepam, repaglinide, rimonabant, rivaroxaban, sertraline, silodosin, simvastatin, solifenacin, temazepam, temsirolimus, tolvaptan, trabectedin, triazolam, warfarin, zidovudine... 

The SSRIs (paroxetine, fluoxetine, sertraline, fluvoxamine, citalopram) and SNRI (ven-lafaxine) have an impressive side-effect profile, and this has contributed to their widespread use. Possible adverse effects include nausea, insomnia, and agitation, but these are generally manageable and diminish over time. More significant is the association of the SSRIs with sexual dysfunction, in both men and women. These effects are longer lasting, and can occur in up to 40% of patients (79). A withdrawal syndrome has also been observed with the SSRIs, characterized by dizziness, headache, and irritability upon abrupt discontinuation. This is much less serious than that observed with benzodiazepines. 

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