Amitriptyline drug interactions

Newberry DL, Bass SN, Mbanefo CO. A fluconazole/amitriptyline drug interaction in three male adidts. Clin Infect bis (1997) 24, 270-1. 

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. 

Determination of amitriptyline plasma concentrations is not routinely recommended but maybe useful in identifying toxicity, drug interactions, or noncompliance (adjustments in dosage should be made according to clinical response not... 

Jerling, M., Bertilsson, L., and Sjoqvist, F. (1994) The use of therapeutic drug monitoring data to document kinetic drug interactions an example with amitriptyline and nortriptyline. Ther Drug Monit 16 1-12. 

Although most physicians avoid the combination of an MAOl with most other antidepressants, a number of reports indicate that MAOIs combined with a TCA can be effective and safe in treatment-resistant patients. This combination should be used only by a physician skilled in their use and familiar with their potential adverse effects and drug interactions. Generally, tertiary amine TCAs have been used in combination with MAOIs. Once the dose of the TCA is established, the MAOl should be slowly added. Never attempt the reverse order without a 2-week delay. It may also be prudent to lower the TCA dose slightly before starting the MAOl. An example might be the addition of phenelzine to amitriptyline, starting with an initial dose of 15 mg and subsequent dose increments weekly as needed. The total dose of an MAOl, used in combination with TCA, is usually lower than when used alone (e.g., 30 to 60 mg per day). When the combination is discontinued, the MAOl should be stopped first. 

St John s wort can cause drug interactions by inducing hepatic microsomal drug-metabolizing enzymes or the drug transporter P-glycoprotein, which causes a net efflux of substrates, such as amitriptyline, from intestinal epithelial cells into the gut lumen (SEDA-24,12). In 12 patients (9 women, 3 men) the addition of St John s wort 900 mg/ day to amitriptyline 150 mg/day led to a 20% reduction in plasma amitriptyline concentrations, while nortriptyline concentrations were almost halved (210). 

Drug-Drug and Drug-Food Interactions. Since cinacalcet is metabolized by multiple hepatic enzymes there is potential for drug interactions. Cinacalcet is also a potent inhibitor of the enzyme CYP2D6. As a result, dose adjustments of concomitant medications that are predominantly metabolized by this enzyme and have a narrow therapeutic index such as flecainide, thioridazine, vinblastine, and most tricyclic antidepressants (i.e., amitriptyline) may be required. ... 

V. Drug or laboratory interactions. There is some evidence that milk thistle may inhibit CYP2C9 and CYP3A4 enzyme activity, which might theoretically increase plasma levels of dmgs metabolized by these enzymes, including amitriptyline, diazepam, clozapine, warfarin, mirtazapine, ketoconazole, and others. Drug interactions with milk thistle extract have not been reported in humans. 

Loomis CW, Racz WJ, Drug interactions of amitriptyline and nortriptyline with warfarin in the rat. Res Commun Chem Pathol Pharmacol (1980) 30, 41-58,... 

Technique-drug interaction Amitriptyline Data in reference [88 ] have been reanalysed [89 ] using more sensitive statistical methods. The reanalysis suggested that interactions of amitriptyline with acupuncture over time on pain intensity and pain relief were statistically significant. Acupuncture by itself was associated with greater pain relief, but the combination of acupuncture and amitriptyline was associated with reduced pain relief and resulted in an adverse treatment interaction on mortality, especially in patients with poor health. The death rate for the combination of acupuncture and amitriptyline was 53% compared with 11% for acupuncture only. 

Schmider J, von Moltke LL, Shader Rl, et al. Extrapolating in vitro data on drug metabolism to in vivo pharmacokinetics evaluation of the pharmacokinetic interaction between amitriptyline and fluoxetine. Drug Metab Rev 1999 31 545-560. 

Kudo K, Imamura T, Jitsufuchi N, Zhang XX, Tokunaga H, Nagata T. Death attributed to the toxic interaction of triazolam, amitriptyline and other psychotropic drugs. Forensic Sci Int 1997 86(1-2) 35 11. 

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... 

In an analysis of phase HI studies, changes in vital signs did not differ between patients given linezolid and comparator drugs (i.e. antibiotics) when either were used with drugs known to interact with MAOIs, including unnamed cyclic antidepressants. A case report describes the serotonin syndrome in an elderly patient treated with linezolid 600 mg every 12 hours, 21 days after amitriptyline 10 mg daily, paroxetine 20 mg daily and alprazolam 500 micrograms daily were started. ... 

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