Imipramine drug interactions

Additional ADRs linked to diet pills include psychosis myocardial ischemia drug interactions, such as the interaction of fenfluramine with imipramine, fenfluramine with amitriptyline or desipramine, or the toxic reaction between fluoxetine and phentermine and the release of serotonin while inhibiting its reuptake, contributing to hyperserotonin reactions. When the next craze takes hold of patients and their physicians, hopefully physicians and pharmacists will take a more vocal position and recommend restraint, xmtil some proof of efficacy and lack of toxicity is shown for new faddish off-label combinations. 

The prevalence of concurrent prescriptions raises concern regarding drug interactions with stimulants. Stimulants, especially MPH, have been used to augment the effects of tricyclic antidepressants in the treatment of refractory depression. Although one early report claimed that circulating levels of imipramine can rise seven fold when taken concurrently with MPH (Wharton et al., 1971), a more recent study found that combining stimulants with desipramine (DMI) did not increase the plasma level of DMI relative to children treated with DMI alone (Cohen et al., 1999). 

Clinicians should be aware of a few drug interactions with Zolpidem. Flumazenil acts as an antagonist to the hypnotic effects of zolpidem. There is decreased alertness when zolpidem is combined with cimetidine. There is an increase in anterograde amnesia in volunteers treated with a combination of imipramine and zolpidem. Haloperidol, ranitidine, chlorpromazine, warfarin, and digoxin, along with cimetidine and flumazenil, do not alter the pharmacokinetics of zolpidem (Salva and Costa, 1995). 

Precautions The tricyclic antidepressants should be used with caution in manic-depressive patients, since they may unmask manic behavior. The tricyclic antidepressants have a narrow therapeutic index for example, 5 to 6 times the maximal daily dose of imipramine can be lethal. Depressed patients who are suicidal should be given only limited quantities of these drugs and should be monitored closely. Drug interactions with the tricyclic antidepressants are shown in Figure 12.5. 

A patient suffering from a depressive disorder is being treated with imipramine. If he uses diphenhydramine for allergic rhinitis, a drug interaction is likely to occur because (A) Diphenhydramine inhibits imipramine metabolism... 

Yoon YR, Shim JC, Shin JG, Shon JH, Kim YH, Cha IJ. Drug interaction between paroxetine and imipramine. Kor Soc Pharmacol Meeting, Seoul, S Korea, October 1997, pl68. 

In pharmacodynamic interactions, the pharmacological effect of a drug is changed by the action of a second drug at a common receptor or bioactive site. For example, low-potency antipsychotics and tertiary amine TCAs have anticholinergic, antihistaminic, a-adrenergic antagonist, and quinidine-Kke effects. Therefore, concurrent administration of chlorpromazine and imipramine results in additive sedation, constipation, postural hypotension, and depression of cardiac conduction. 

Imipramine Mixed and variable blockade of NET and SERT Like SNRIs plus significant blockade of autonomic nervous system and histamine receptors Major depression not responsive to other drugs chronic pain disorders incontinence obsessive-compulsive disorder (clomipramine) Long half-lives CYP substrates active metabolites Toxicity Anticholinergic, G.-blocking effects, sedation, weight gain, arrhythmias, and seizures in overdose Interactions CYP inducers and inhibitors... 

Differential scanning calorimetry has also been used to study the interaction of DPPC liposomes with the neuromediators norepinephrine and 5-hydroxytryptamine and four antidepressant drugs (imipramine, indalpine, citalopram, and milnacipran) known to inhibit uptake of these neurotransmitters [39]. Changes in the thermograms, transition temperature maximum, Tt, and ATt were determined as a function... 

Tab. 5.27 Correlation coefficients between drug-membrane interaction parameters and biological data of the seven modifiers studied, (c/s- and trans-flupentixol, chlorpromazine, trifluoperazine, triflupromazine, imipramine, and quinacrine). Chlorpromazine was omitted from regression corresponding to the MCF-7/DOX cell line. Quinacrine data were not available for the P388/DOX cell line. (Reprinted from Tab. 2 of ref. 11 7, with permission from Bertelsmann-Springer)...

LEVODOPA, SELEGILINE, POSSIBLY RASAGILINE, ENTACAPONE, TOLCAPONE MAOIs Risk of adrenergic syndrome -hypertension, hyperthermia, arrhythmias - and dopaminergic effects with selegiline Levodopa and related drugs are precursors of dopamine. Levodopa is predominantly metabolized to dopamine, and a smaller proportion is converted to epinephrine and norepinephrine. Effects are due to inhibition of MAOI, which breaks down dopamine and sympathomimetics Avoid concurrent use. Onset may be 6-24 hours after ingestion. Carbidopa and benserazide, which inhibit dopa decarboxylase that converts L-dopa to dopamine, is considered to minimize this interaction. However, MAOIs should not be used in patients with Parkinson s disease on treatment with levodopa. Imipramine and amitriptyline are considered safer by some clinicians... 

Spina E, Campo GM, Avenoso A, PoUicino MA, Capuh AP. Interaction between Fluvoxamine and imipramine/desipra-mine in four patients. Ther Drug Monit 1992 14(3) 194-6. 

Radwanska, A. Frackowiak, T. Ibrahim, H. Aubry, A.-F. Kaliszan, R. Chromatographic mcxlelling of interactions between melanin and phenothiazine and dibenzapine drugs. Biomed.Chromatogr., 1995, 9, 233-237 [also acetopromazine, chlorpromazine, clomipramine, ethopromazine, fluphenazine, imipramine, perphenazine, prcxihlorperazine, promazine, propiomazine, thioridazine, trifluoperazine, tri-fluopromazine, trimeprazine]... 

Gram LF, Hansen MG], Sindrup SH et al. Citalopram interaction studies with levomepromazine, imipramine and lithium. Therap Drug Monitor 1993 15 18-24. 

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