Fluvoxamine drug administrations

The prototypical serotonin reuptake inhibitor (SRI) medication is the non-selective agent clomipramine, a tricyclic antidepressant (TCA). The Selective SRIs (SSRIs) include fluoxetine (Prozac), sertraline (Zoloft), paroxetine (Paxil), fluvoxamine (Luvox), and citalo-pram (Celexa). The Food and Drug Administration (FDA) approved clinical indications for these medications are described in Table 22.1. 

The selective serotonin reuptake inhibitors (SSRls) have received increased attention in the treatment of anxiety disorders. With the recent Food and Drug Administration (FDA) approval of fluoxetine and fluvoxamine in the treatment of obsessive-compulsive disorder, it has been made clear that this... 

The addition of low-dose fluvoxamine (50-100 mg/day) to neuroleptic drug treatment may improve the negative symptoms in patients with schizophrenia, but involves a risk of a drug interaction. In 12 in-patients with schizophrenia receiving 6 mg/day of haloperidol, incremental doses of fluvoxamine (25, 75, and 150 mg/day for 2 weeks each) respectively increased haloperidol plasma concentrations by 120%, 139%, and 160% of those before fluvoxamine co-administration in spite of the increase, there were no particular adverse effects (50). 

The Food and Drug Administration (FDA) has approved five antidepressants for the management of OCD clomipramine, fluoxetine, fluvoxamine, paroxetine, and sertraline. In adolescents with OCD, CBT is generally selected first for mild OCD, but CBT plus an SSRI (e.g., fluoxetine, fluvoxamine, sertraline, or paroxetine) are used for more severe OCD. In adults, CBT is the initial choice for mild OCD, and CBT plus an SSRI or an SSRI alone is selected for more severe OCD. Figure 70-2 is an algorithm for the treatment of OCD. 

Theophylline is a narrow therapeutic index drug with significant difference in bioavailability following oral administration. The half-life of the drug is increased by heart failure, cirrhosis and viral infections, in elderly patients, and by certain drugs, such as cimetidine, ciprofloxacin, oral contraceptives and fluvoxamine. The half-life is decreased in smokers, chronic alcoholism, and by certain drugs, such as phenytoin, rifampicin and carbamazepine. 

The most common interactions with SSRIs are pharmacokinetic interactions. For example, paroxetine and fluoxetine are potent CYP2D6 inhibitors (Table 30-4). Thus, administration with 2D6 substrates such as TCAs can lead to dramatic and sometimes unpredictable elevations in the tricyclic drug concentration. The result may be toxicity from the TCA. Similarly, fluvoxamine, a CYP3A4 inhibitor, may elevate the levels of concurrently administered substrates for this enzyme such as diltiazem and induce bradycardia or hypotension. Other SSRIs, such as citalopram and escitalopram, are relatively free of pharmacokinetic interactions. The most serious interaction with the SSRIs are pharmacodynamic interactions with MAOIs that produce a serotonin syndrome (see below). 

LITHIUM SSRIs Lithium may enhance the pharmacologic effects of SSRIs and potentiate the risk of serotonin syndrome. Excessive somnolence has been reported with fluvoxamine. However, there are reports of both T and l plasma concentrations of lithium. There are reports of lithium toxicity and of serotonergic effects Lithium is a direct stimulant of 5-HT receptors, while SSRIs i the reuptake of 5- HT these are considered to t the effects of serotonin in the brain. Seizures are a neurotoxic effect of lithium and could occur even with plasma lithium concentrations within the normal range. SSRIs and lithium may have additive effects to cause seizures Be aware of the possibility of serotonin syndrome. Also need to monitor lithium levels with appropriate dose adjustments during co-administration > For signs and symptoms of serotonin toxicity, see Clinical Features of Some Adverse Drug Interactions, Serotonin toxicity and serotonin syndrome... 

BUPROPION 1. ANTICANCER DRUGS - thiotepa 2. ANTIDEPRESSANTS-fluoxetine, fluvoxamine, paroxetine, sertraline 3. ANTIVIRALS - efavirenz, protease inhibitors t plasma concentrations of bupropion and risk of adverse effects Inhibition of CYP2B6 Warn patients about adverse effects and use alternatives when possible. Avoid co-administration of bupropion with protease inhibitors. Co-adminis-ter efavirenz and bupropion with caution. A retrospective study showed that two patients received a combination without reported adverse effects. Potential T risk of seizures... 

The diversity of the SSRIs is evident not only in their chemical structures, but also in their pharmacokinetic profiles. Fluoxetine has an elimination half-fife of 2 to 3 days (4 to 5 days with multiple dosing). The single-dose hah-hfe of norfluoxetine, the active metabolite, is 7 to 9 days. Paroxetine and sertrahne have half-lives of approximately 24 hours. Unlike paroxetine, sertraline has an active metabolite, but the metabohte contributes minimally to the pharmacologic effects. Escitalopram has a half-life of approximately 30 hours. Peak plasma concentrations of citalopram are observed within 2 to 4 hours after dosing, and the elimination half-life is about 30 hours. The SSRIs, with the exception of fluvoxamine, escitalopram, and citalopram, are extensively bound to plasma proteins (94% to 99%). The SSRIs are extensively distributed to the tissues, and aU, with the possible exception of citalopram, may have a nonlinear pattern of drug accumulation with long-term administration. ... 

Fluvoxamine inhibits the cytochrome P450 liver catabolic enzymes (predominantly this is inhibition of N-demethylation), leading to an increase in tricyclic antidepressant (TCA) serum levels. Plasma levels of several antidepressant drugs (e.g. amitriptyline, clomipramine, desipramine, imipramine, maprotiline, and nortriptyline) have been reported to increase by up to 4-fold during co-administration with fluvoxamine. Fluvoxamine at a daily dose of 50-100 mg causes a 3-4-fold increase in the plasma concentration of mirtazapine. 

Inositol significantly reduced the number of panic attacks per week in patients as compared to fluvoxamine and without the nausea and tiredness that are common with fluvoxamine. Inositol has few known side effects, thus making it attractive for administration to patients with manic-depression who are ambivalent about taking other antidepressant drugs (82). 

---