Imipramine Cimetidine

Shapiro PA. Cimetidine-imipramine interaction case report and comments. Am J Psychiatry (1984) 141, 152. 

Miller DD, Macklin M. Cimetidine-imipramine interaction a case report. Am J Psychiatry (1983) 140, 351-2. 

Fig. 4.3 CSF concentration/free (unbound) plasma concentration ratios for neutral and basic drugs 1, ritropirronium 2, atenolol 3, sulpiride 4, morphine 5, cimetidine 6, meto-prolol 7, atropine 8, tacrine 9, digoxin 10, propranolol 11, carbamazepine 12, ondansetron 13, diazepam 14, imipramine 15, digitonin 16, chlorpromazine and acidic drugs, a, salicylic acid b, ketoprofen c, oxyphenbutazone and d, indomethacin compared to log D.

Imipramine (Tofranil) [Antidepressant/TCA] WARNING Close observation for suicidal thinking or unusual changes in behavior Uses Depres-sion, enuresis, panic attack, chronic pain Action TCA t CNS synaptic serotonin or norepinephrine Dose Adults. Hospitalized Initial 100 mg/24 h PO in doses T over several wk 300 mg/d max Output Maint 50-150 mg PO hs, 300 mg/24 h max Peds. Antidepressant 1.5-5 mg/kg/24 h daUy-qid Enuresis >6 y 10-25 mg PO qhs T by 10-25 mg at 1-2-wk int vals (max 50 mg for 6-12 y, 75 mg for >12 y) Rx for 2-3 mo, then tap Caution [D, /-] Contra Use w/ MAOIs, NAG, acute recovery from MI, PRG, CHF, angina, CVD, arrhythmias Disp Tabs, caps SE CV Sxs, dizziness, xerostomia, discolored urine Interactions t Effects W/ amiodarone, anticholinergics, BBs, cimetidine, diltiazem, Li, OCPs, quinidine, phenothiazines, ritonavir, verapamil, EtOH, evening primrose oil t effects OF CNS depressants, hypoglycemics, warfarin T risk of serotonin synd W/MAOIs 4-... 

Substrates Inhibitors Inducers CYP1A2 Acetaminophen, caffeine, clozapine, imipramine, theophylline, propranolol Most fluoroquinolone antibiotics, fluvoxamine, cimetidine Tobacco smoking, charcoal-broiled foods, cruciferous vegetables, omeprazole... 

Henauer, S.A. and Hollister, T.E. (1984) Cimetidine interaction with imipramine and nortriptyline. Clin Pharmacol Ther 35 183—187. 

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). 

Cimetidine Lidocaine, propranolol, verapamil, imipramine Increased absorption... 

Fluoxetine, paroxetine, bupropion, duloxetine, and other CYP450 2D6 inhibitors may increase TCA concentrations Fluvoxamine, a CYP450 1A2 inhibitor, can decrease the conversion of imipramine to desmethylimipramine (desipramine) and increase imipramine plasma concentrations Cimetidine may increase plasma concentrations of TCAs and cause anticholinergic symptoms Phenothiazines or haloperidol may raise TCA blood concentrations May alter effects of antihypertensive drugs may inhibit hypotensive effects of clonidine... 

Wells BG, Pieper JA, Self TH, Stewart CF, Waldon SL, Bobo L, Warner C. The effect of ranitidine and cimetidine on imipramine disposition. Eur J Chn Pharmacol 1986 31(3) 285-90. 

OCT3 (SLC22A3) Human MPP+, guanidine, monoamine neurotransmitters Drugs cimetidine, tyramine Corticosterone, p-estradiol, MPTP, o-methylisoprenaline, progesterone, SKF550 Drugs clonidine, desipramine, imipramine, phenoxybenzamine, prazosin, procainamide... 

Octnl (Slc22a4) Rat TEA, MPP+ DMA, nicotine Drugs cimetidine, desipramine, imipramine, procainamide, verapamil... 

You refer Gail to the psychiatrist, who instructs her to discontinue imipramine and orders a blood level to be drawn that afternoon. The psychiatrist suspects that Gail s metabolism of imipramine may be impaired by the addition of cimetidine. The symptoms that Gail describes are consistent with tricyclic toxicity. Cimetidine is known to inhibit the ability of liver enzymes to metabolize numerous other medications, including antidepressants (American Society of Hospital Pharmacists 1993). 

You find out several days later that Gail s imipramine level was elevated by about 40 percent. Her psychiatrist feels it will be safe for her to resume imipramine at a lower dose if she continues taking cimetidine. At her next session she is undecided about restarting her antidepressant and wishes to discuss it with you. 

Clinically important, potentially hazardous interactions with alcohol, cimetidine, erythromycin, imipramine, ketoconazole, promethazine, rifampicin, rifampin, thioridazine... 

Also analyzed acebutolol, acepromazine, acetaminophen, acetazolamide, acetophenazine, albuterol, amitriptyline, amobarbital, amoxapine, antipsrrine, atenolol, atropine, azata-dine, baclofen, benzocaine, bromocriptine, brompheniramine, brotizolam, bupivacaine, buspirone, butabarbital, butalbital, caffeine, carbamazepine, cetirizine, chlorqyclizine, chlordiazepoxide, chlormezanone, chloroquine, chlorpheniramine, chlorpromazine, chlorpropamide, chlorprothixene, chlorthalidone, chlorzoxazone, cimetidine, cisapride, clomipramine, clonazepam, clonidine, clozapine, cocaine, codeine, colchicine, qyclizine, (yclo-benzaprine, dantrolene, desipramine, diazepam, diclofenac, diflunisal, diltiazem, diphenhydramine, diphenidol, dipheno late, dipyridamole, disopyramide, dobutamine, doxapram, doxepin, droperidol, encainide, ethidium bromide, ethopropazine, fenoprofen, fentanyl, flavoxate, fluoxetine, fluphenazine, flurazepam, flurbiprofen, fluvoxamine, fii-rosemide, glutethimide, glyburide, guaifenesin, haloperidol, homatropine, hydralazine, hydrochlorothiazide, hydrocodone, hydromorphone, hydro g chloroquine, hydroxyzine, ibuprofen, imipramine, indomethacin, ketoconazole, ketoprofen, ketorolac, labetalol, le-vorphanol, lidocaine, loratadine, lorazepam, lovastatin, loxapine, mazindol, mefenamic acid, meperidine, mephenytoin, mepivacaine, mesoridazine, metaproterenol, methadone, methdilazine, methocarbamol, methotrexate, methotrimeprazine, methoxamine, methyl-dopa, methylphenidate, metoclopramide, metolazone, metoprolol, metronidazole, midazolam, moclobemide, morphine, nadolol, nalbuphine, naloxone, naphazoline, naproxen, nifedipine, nizatidine, norepinephrine, nortriptyline, oxazepam, oxycodone, oxymetazo-line, paroxetine, pemoline, pentazocine, pentobarbital, pentoxifylline, perphenazine, pheniramine, phenobarbital, phenol, phenolphthalein, phentolamine, phenylbutazone, phenyltoloxamine, phenytoin, pimozide, pindolol, piroxicam, pramoxine, prazepam, prazosin, probenecid, procainamide, procaine, prochlorperazine, procyclidine, promazine, promethazine, propafenone, propantheline, propiomazine, propofol, propranolol, protriptyline, quazepam, quinidine, quinine, racemethorphan, ranitidine, remoxipride, risperidone, salicylic acid, scopolamine, secobarbital, sertraline, sotalol, spironolactone, sulfinpyrazone, sulindac, temazepam, terbutaline, terfenadine, tetracaine, theophylline, thiethyl-perazine, thiopental, thioridazine, thiothixene, timolol, tocainide, tolbutamide, tolmetin, trazodone, triamterene, triazolam, trifluoperazine, triflupromazine, trimeprazine, trimethoprim, trimipramine, verapamil, warfarin, xylometazoline, yohimbine, zopiclone... 

Wong, S.H.Y. McHugh, S.L. Dolan, J. Cohen, K.A. Tricyclic antidepressant analysis by reversed-phase liquid chromatography using phenyl columns. J.Liq.Chromatogr., 1986, 9, 2511-2538 [also acetaminophen, amobarbital, amoxapine, barbital, chlordiazepoxide, chlorpromazine, cimetidine, clomipramine, codeine, desipramine, desmethyldoxepin, diazepam, doxepin, fluphenazine, flurazepam, glutethimide, hydroxyamoxapine, imipramine, lorazepam, maprotiline, meperidine, metabolites, nortriptyline, oxazepam, pentobarbital, perphenazine, phenobarbital, phenytoin, propoxyphene, protriptyline, secobarbital, thioridazine, trazodone]... 

Simultaneous amoxapine, chlordiazepoxide, chlorpromazine, cimetidine, desipramine, diazepam, doxepin, flurazepam, imipramine, lorazepam, norfluoxetine, nortriptyline, oxazepam, pentobarbital, perphenazine, phenobarbital, phen5doin, prochlorperazine, secobarbital, thioridazine, trifluoperazine Noninterfering acetaminophen, codeine, meperidine Interfering amitriptyline, propo q>hene... 

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