Bupropion toxicity

C. Nortriptyline (Pamelor) is a TCA, and as a class these drugs require at least one steady-state blood level to safely and effectively use the medication. Paroxetine, venlafaxine, and bupropion have not had blood levels correlated to response, and their relatively low toxicity does not require therapeutic blood monitoring. Nardil is a MAOI, which can be... 

Geriatric Considerations - Summary Bupropion has several advantages as an antidepressant agent for use in older adults. It has neither the anticholinergic or cardiac toxicities of the tricyclic antidepressants, and has fewer sexual side effects than selective serotonin reuptake inhibitors. Because this drug may lower seizure threshold, it should be used with caution in older adults with increased risk of seizures (e.g., previous stroke, early-onset Alzheimer s disease). 

Bupropion overdose (n = 58) and combined overdoses of bupropion and benzodiazepines (n = 9) have been associated with symptoms of neurological toxicity, including lethargy, tremors, and seizures, and an absence of cardiovascular toxicity (Spiller et ah, 1994). 

Case reports have suggested that adding stimulant medications or combining a SSRI and a TCA or bupropion may also be effective (APA, 2000), but these combinations need to be done with caution, given the possibility of drug interactions (e.g., SSRIs cytochrome inhibition leading to toxic TCA levels). Additionally, in adults, the combination of antidepressants and psychotherapy (CBT, IPT) for patients with severe or treatment-resistant depression has been found useful (APA, 2000 Keller et al., 2000). 

The danger of bupropion overdose is limited to the risk of seizures for the most part. However, seizures are seldom life threatening unless they result in motor vehicle accidents, falls, or other trauma-related events. Bupropion s lack of significant cardiovascular or respiratory toxicity means that it is rarely lethal in overdose. 

In contrast to anticonvulsants and alcohol, drugs such as bupropion, fluoxetine, fluvoxamine, nefazodone, quinidine, paroxetine, and some antipsychotics can inhibit specific CYP enzymes (7, 11, 36, 37, 41, 42, 43 and 44). Thus, TCAs, certain BZDs, bupropion, some steroids, and antipsychotics can all have their metabolism inhibited by drugs such as fluoxetine. For example, fluoxetine at 20 mg/day produces on average a 500% increase in the levels of coprescribed drugs which are principally dependent on CYP 2D6 for their clearance. That can lead to serious or even life-threatening toxicity if the drug has a narrow therapeutic index and the dose is not adjusted for the change in clearance caused by the coadministration of fluoxetine. 

Bupropion Increased norepinephrine and dopamine activity Presynaptic release of catecholamines Major depression smoking cessation (bupropion) sedation Extensive metabolism in liver Toxicity Lowers seizure threshold (amoxapine,... 

Bupropion + L-dopa —> enhanced therapeutic and toxic effects of L-dopa can cause hallucinations, confusion and dyskinesias. Changes due to additive dopaminergic effects. 

AMIODARONE DRUG DEPENDENCE THERAPIES-BUPROPION T plasma concentrations of amiodarone, with risk of toxic effects Bupropion and its metabolite hydroxybupropion inhibit CYP2D6 Initiate therapy of these drugs at the lowest effective dose... 

AMPHETAMINES BUPROPION 1. t plasma concentrations of these substrates, with risk of toxic effects 2. t risk of seizures. This risk is marked in elderly people, patients with a history of seizures, those with an addiction to opiates/ cocaine/stimulants, and those with diabetes treated with oral hypoglycaemics or insulin 1. Bupropion and its metabolite hydroxybupropion inhibit CYP2D6 2. Bupropion is associated with a dose-related risk of seizures. These drugs that lower seizure threshold are individually epileptogenic. They have additive effects when combined 1. Initiate therapy with these drugs, particularly those with a narrow therapeutic index, at the lowest effective dose. Interaction is likely to be important with substrates for which CYP2D6 is considered the only metabolic pathway (e.g. amphetamines) 2. Extreme caution. The dose of bupropion should not exceed 450 mg/day (or 150 mg/day in those with severe hepatic cirrhosis)... 

PHENELZINE DRUG DEPENDENCE THERAPIES-BUPROPION t acute toxicity of bupropion Uncertain Be aware... 

CHLORPROMAZINE, CLOZAPINE, HALOPERIDOL, OLANZAPINE BUPROPION T plasma concentrations of these drugs with risk of toxic/adverse effects Smoking induces mainly CYP1A2 and CYP2E1. Thus de-induction takes place following cessation of smoking Be aware and watch for early features of toxicity. Consider reducing the dose... 

CANNABIS BUPROPION Unpredictable changes in plasma concentration. Risk of toxicity or therapeutic failure, particularly of drugs with a narrow therapeutic index Induction or inhibition of CYP3A4-mediated metabolism by cannabis. It is not yet known whether the effects are dependent on the degree of cannabis consumption Be aware. Watch for signs of toxicity, especially when cannabis use abruptly changes... 

CINACALCET BUPROPION T plasma concentrations of these substrates, with risk of toxic effects Bupropion and its metabolite hydroxybupropion inhibit CYP2D6 Initiate therapy of these drugs, particularly those with a narrow therapeutic index, at the lowest effective dose. Interaction is likely to be important with substrates for which CYP2D6 is considered the only metabolic pathway (e.g. hydrocodone, oxycodone, desipramine, paroxetine, chlorpheniramine, mesoridazine, alprenolol, amphetamines, atomoxetine)... 

Monitor for Levodopa toxicity dose of Levodopa should be reduced if necessary Avoid use of bupropion in patients with history of seizure disorder... 

Because this group as a whole engages in frequent suicidal acting out, it is advisable to treat borderline patients with medications that have been found to have a low degree of toxicity when taken in overdose. These include antipsychotics and the following antidepressants fluoxetine, paroxetine, bupropion (note above caution), trazodone, and sertraline. Most other antidepressants are quite toxic when taken in overdose. 

Medications play an important part in the treatment of ADD. Stimulants are the mainstay of the treatment of ADD methylphenidate (Ritalin), dextroamphetamine (Dexedrine), and pemoline (Cylert). These differ in their half-lives, with Ritalin having the shortest and Cylert the longest. A warning has recently been issued about Cylert because of reports of sometimes fatal liver toxicity. Thus, it is recommended that it be used only if methylphenidate and dextroamphetamine are ineffective. There is individual variability in resporise, so that a person who does not respond to one may respond well to another. Other medications can also be effective in the treatment of ADD and may be useful, especially in residual ADD, where substance abuse may be an issue. These include tricyclic antidepressants (especially desipramine and imi-pramine) SSRIs, bupropion, venlafaxine, and clonidine. There are reports of antipsy-chotics and lithium being helpful in selected cases, as well. 

High suicide risk Less toxic antidepressants (fluoxetine, trazodone, paroxetine, sertraline, bupropion, venlafaxine, nefazodone)... 

Miscellaneous toxic effects of tricychc antidepressants include jaundice, leukopenia, and rashes, but these are very infrequent. Weight gain is a common adverse effect of many antidepressants but is less likely with the SSRls and is rare with bupropion (Table 17-1). Excessive sweating also is common. 

Drugs whose therapeutic, effects were shown to be opposed by bupropion [ 00 J Drugs that can cause significant and severe side-effects due to additive impact (not due to toxicity)... 

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