Antidepressants interactions with other drugs

The main problems with early, irreversible MAOIs were adverse interactions with other drugs (notably sympathomimetics, such as ephedrine, phenylpropanolamine and tricyclic antidepressants) and the infamous "cheese reaction". The cheese reaction is a consequence of accumulation of the dietary and trace amine, tyramine, in noradrenergic neurons when MAO is inhibited. Tyramine, which is found in cheese and certain other foods (particularly fermented food products and dried meats), is normally metabolised by MAO in the gut wall and liver and so little ever reaches the systemic circulation. MAOIs, by inactivating this enzymic shield, enable tyramine to reach the bloodstream and eventually to be taken up by the monoamine transporters on serotonergic and noradrenergic neurons. Fike amphetamine, tyramine reduces the pH gradient across the vesicle membrane which, in turn, causes the vesicular transporter to fail. Transmitter that leaks out of the vesicles into the neuronal cytosol cannot be metabolised because... 

This antidepressant can interact with other drugs via its two mechanisms of action serotonin and NE uptake inhibition. The former action means that the same pharmacodynamic interactions will occur with venlafaxine as with SSRIs, including the serotonin syndrome. At higher doses, venlafaxine is also prone to the same pharmacodynamic interactions as NSRIs such as secondary amine TCAs like desipramine and with newer NSRIs such reboxetine. Thus, the combination of high-dose venlafaxine plus an MAOl could produce a hypertensive crisis as well as the serotonin syndrome. 

For the most part, antidepressants are considered safe. However, they may interact with other drugs taken by the patient—and the physician prescribing one of these drugs must take this into consideration. Additionally, some medical problems already under treatment may increase in severity in the presence of an antidepressant. 

Little research has been conducted on how LSD interacts with other drugs. The most complete research is with antidepressant drugs because these commonly prescribed medications affect the same brain chemical, serotonin, that LSD does. There are three types of antidepressants, and each interacts differently with LSD ... 

Antidepressant use offers considerable scope for an adverse interaction with other drugs through both pharmacodynamic and pharmakokinetic mechanisms. It is therefore prudent always to check specific sources for a possibly unwanted outcome whenever a new drug is added or removed to a prescription list that includes an antidepressant. 

Treatment is symptomatic and supportive. Concerns have been noted in the literature about the potential for adverse interactions with other drugs, especially antidepressants and sympathomimetics. 

Antidepressants are considered to have additive effects, therefore combined use is not recommended. Inhibitors of serotonin reuptake by CNS neurons may interact with other drugs or circumstances which cause serotonin release. The enhancement of the serotonergic effects may produce a life-threatening serotonin syndrome. Drugs which can increase the serotonin level when taken in combination with SSRIs include TCAs, MAOIs, reversible inhibitors of monoamine oxidase, carbamazepine, lithium, or serotoneric substances. These drugs should not be coadministered with SSRIs and they may increase the risks of developing a serotonin syndrome. 

Patients with coexisting cardiovascular and pulmonary conditions (e.g., ARDS, pulmonary infection, pulmonary aspiration) may be more susceptible to the toxic effects or complications of tricyclic antidepressant poisoning. The influence of chronic exposure to tricyclic antidepressants on the risks of an acute overdose is unclear. Tricyclic antidepressants interact with other central nervous system depressant drugs, which together may lead to increased central nervous system and respiratory depression. 

Would protein binding interactions with other drugs (e.g., warfarin) be likely to occur with tricyclic antidepressants ... 

Indications for the MAO inhibitors are limited and must be weighed against their potential toxicity and their complex interactions with other drugs. Thus, the MAO inhibitors generally are considered drugs of late choice for the treatment of severe depression. Nevertheless, MAO inhibitors sometimes are used when vigorous trials of several standard antidepressants have been unsatisfactory and when ECT is refused. In addition, MAO inhibitors may have selective benefits for... 

The major drug interactions of antidepressants are shown in Table 35—6.9,19,30 Antidepressants cause both pharmacodynamic (e.g., additive pharmacologic effects) and pharmacokinetic (e.g., changes in drug levels) interactions with other medications. 

Hesse LM, Venkatakrishnan K, Court MH, et al. CYP2B6 mediates the in vitro hydroxyla-tion of bupropion potential drug interactions with other antidepressants. Drug Metab Dispos... 

To review pharmacokinetic interactions of antidepressants with other drugs. 

Sulfonylureas In acute poisoning with sulfonylureas, the stomach should be washed and treated with activated charcoal, and hypoglycemia must be treated. Sulfonylureas interact with oral contraceptives, thiazide diuretics, corticosteroids, adrenaline, chlorpromazine, ACE inhibitors, some NSAIDs, antihistamines, anticoagulants, MAOIs, antidepressants, and many other drugs. Care must be exercised when treating with sulfonylureas. 

The use of cisapride and its benefit to harm balance in children has been reviewed (25). Overall it is well tolerated. The most common adverse effects are diarrhea, abdominal cramps, borborygmi, and colic. Serious adverse events are rare and include isolated cases of extrapyramidal reactions, seizures in epileptic patients, cholestasis, QT interval prolongation and ventricular dysrhythmias, anorexia, and enuresis. Interactions of cisapride with other drugs are similar to those reported in adults. Co-administration of drugs that inhibit CYP3A4, such as imidazoles, macrolide antibiotics, the antidepressant nefazodone, and protease inhibitors such as ritonavir, are contraindicated. Furthermore, co-administration of anticholinergic drugs can compromise the beneficial effects of cisapride. 

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