Diphenhydramine Interactions
- Amantadine
- Amoxapine
Antimuscarinics
Anxiolytics, Sedatives, and Hypnotics
Barbiturates
- Buprenorphine
- Butorphanol
- Cetirizine
- Clozapine
- Cyclobenzaprine
- Dextroamphetamine
- Disopyramide
- Doxercalciferol
- Dronabinol, THC
- Entacapone
- Ethanol
General Anesthetics
- Haloperidol
- Maprotiline
Monoamine oxidase inhibitors (MAOIs)
- Nabilone
- Nalbuphine
- Olanzapine
Opiate agonists
- Orphenadrine
- Pentazocine
Phenothiazines
- Pramipexole
- Pregabalin
- Risperidone
- Ropinirole
Sedating H1-blockers
- Tolcapone
- Trazodone
Tricyclic antidepressants
Diphenhydramine Interactions
Because diphenhydramine causes pronounced sedation, an enhanced CNS depressant effect may occur when it is combined with other sedating H1-blockers or with cetirizine. Due to the duplicative pharmacology and potential for additive side effects, combination of diphenhydramine with other antihistamines is not generally recommended.
MAOIs may prolong and intensify the anticholinergic effects of antihistamines. The anticholinergic activity of MAOIs is minimal; however, anticholinergic effects sometimes occur. Most manufacturers recommend that sedating H1-antagonists not be used within two weeks of therapy with a MAOI.
Because diphenhydramine can cause pronounced sedation, an enhanced CNS depressant effect may occur when it is combined with other CNS depressants including anxiolytics, sedatives, and hypnotics (such as barbiturates and benzodiazepines), buprenorphine, butorphanol, carisoprodol, clozapine, dronabinol, THC, droperidol, entacapone, ethanol, general anesthetics, haloperidol, methocarbamol, mirtazapine, molindone, nabilone, nalbuphine, nefazodone, olanzapine, opiate agonists, pentazocine, phenothiazines, pimozide, pramipexole, pregabalin, procarbazine, quetiapine, risperidone, ropinirole, tolcapone, tramadol, trazodone, tricyclic antidepressants, or with other sedating H1-blockers. In addition, concurrent use of cannabinoids with sedating H1-blockers may result in additive tachycardia, which may be pronounced.
The anticholinergic effects of diphenhydramine may be significant and may be enhanced when combined with antimuscarinics. Other commonly used drugs with moderate to significant anticholinergic effects include amantadine, amoxapine, clozapine, cyclobenzaprine, disopyramide, maprotiline, olanzapine, orphenadrine, most phenothiazines, and most tricyclic antidepressants. Clinicians should note that antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation. With many of the listed agents, additive drowsiness may also occur when combined with sedating antihistamines.
Dextroamphetamine and other amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers (i.e., diphenhydramine). This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Doxercalciferol is converted in the liver to 1,25-dihydroxyergocalciferol, the major active metabolite, and 1-alpha, 24-dihydroxyvitamin D2, a minor metabolite. Although not specifically studied, cytochrome P450 enzyme inhibitors including diphenhydramine may inhibit the 25-hydroxylation of doxercalciferol, thereby decreasing the formation of the active metabolite and thus, decreasing efficacy. Patients should be monitored for a decrease in efficacy if diphenhydramine is coadministered with doxercalciferol.
[ Last revised: 6/21/2006 3:34:00 PM ]
References
. Clozaril® (clozapine) package insert. East Hanover, NJ; Novartis Pharmaceuticals Corporation; 2005 May.
. Haldol® injection for immediate release (haloperidol) package insert. Raritan, NJ: Ortho-McNeil Pharmaceutical, Inc.;2001 Sept.
. Ultram® (tramadol) package insert. Raritan, NJ.; Ortho-McNeil Pharmaceutical, Inc.; 2001 Aug.
. Risperdal® (risperidone) package insert. Titusville, NJ: Janssen Pharmaceutica Products, L.P.; 2003 Dec.
. Dexedrine® (dextroamphetamine) package insert. Research Triangle Park, NC; GlaxoSmithKline; 2002 Jan.
. Orap® (pimozide) package insert. Sellersville, PA: Teva Pharmaceuticals USA; 1999 Aug.
. Suboxone® (buprenorphine and naloxone)/Subutex® (buprenorphine) package insert. Richmond, VA: Reckitt Benckiser Pharmaceuticals, Inc.; 2002 Oct.
. Matulane® (procarbazine) package insert. Gaithersburg, MD: sigma-tau Pharmaceuticals, Inc.; 2002 July.
. Mirtazapine package insert. Ft Lauderdale, FL: Andrx Pharmaceuticals, Inc.; 2003 Sept.
. Serzone® (nefazodone) package insert. Princeton, NJ: Bristol-Myers Squibb Company; 2003 Sep.
. Desyrel® (trazodone) package insert. Princeton, NJ: Bristol-Myers Squibb; 2003 Sep.
. Droperidol Injection, USP package insert. North Chicago, IL: Abbott Laboratories; 2002 Aug.
. Zyprexa® (olanzapine) package insert. Indianapolis IN: Eli Lilly and Company; 2004 March.
. Moban® (Molindone) package insert. Chadds Ford, PA: Endo Pharmaceuticals Inc; 2003 Jan.
. Tasmar® (tolcapone) package insert. Nutley, NJ: Roche Laboratories Inc..; 1998 Oct.
. Zyrtec® (cetirizine) package insert. New York, NY: Pfizer Labs; 2004 Mar.
. Mirapex® (pramipexole dihydrochloride) package insert. Ridgefield, CT: Boehringer Ingelheim Pharmaceuticals, Inc.; 2004 Jan.
. Comtan® (entacapone) package insert. East Hanover, NJ: Novartis Pharmaceuticals; 2000 March.
. Seroquel® (quetiapine fumarate) package insert. Wilmington, DE: AstraZeneca Pharmaceuticals LP; 2004 Jan.
. Stadol NS® (butorphanol tartrate) package insert. Princeton, NJ: Bristol-Myers Squibb Company; 2002 March.
. Hoffman BB, Lefkowitz RJ. Atropine, scopolamine, and related antimuscarinic drugs. Gilman AG, Rall TW, Nies AS, Taylor P, (eds.) In: Goodman and Gilman’s Pharmacological Basis of Therapeutics. 8th ed., New York, Pergamon Press. 1990. 150 - 61.
. Seixas FA. Alcohol and its drug interactions. Ann Intern Med 1975;83:86 - 92.
. Hoffman BB, Lefkowitz RJ. Monoamine oxidase (MAO) inhibitors. Gilman AG, Rall TW, Nies AS, Taylor P, (eds.) In: Goodman and Gilman’s Pharmacological Basis of Therapeutics. 8th ed., New York, Pergamon Press. 1990. 416 - 17.
. Welch MJ, Meltzer EO, Simons FE. H1-antihistamines and the central nervous system. Clin Allergy Immunol 2002;17:337 - 88.
. Talwin® Nx (pentazocine and naloxone) package insert. New York, NY: Sanofi-Synthelabo, Inc.; 2003 May.
. Nubain® (nalbuphine hydrochloride) package insert. Chadds Ford, PA: Endo Pharmaceuticals Inc; 2003 May.
. Evers AS, Crowder CM. General Anesthetics. Gilman AG, Hardman JG, Limbird LE, (eds.) In: Goodman and Gilman’s The Pharmacological Basis of Therapeutics. 10th ed., New York, McGraw-Hill Companies. 2001:337 - 365.
. Hectorol® (doxercalciferol) package insert. Middleton, WI: Bone Care International, Inc.; 2005 Jun.
. Baldessarini RJ. Drugs and the treatment of psychiatric disorders: psychosis and anxiety. In: Hardman JG, Limbird LE, Molinoff PB, et al., eds. Goodman and Gilman’s the pharmacological basis of therapeutics, 9th edn. New York: McGraw Hill, 1996;399 - 430.
. Baldessarini RJ. Drugs and the treatment of psychiatric disorders: depression and mania. In: Hardman JG, Limbird LE, Molinoff PB, et al., eds. Goodman and Gilman’s the pharmacological basis of therapeutics, 9th edn. New York: McGraw Hill, 1996;431 - 459.
. Hobbs WR, Rall TW, Verdoorn TA. Hypnotics and sedatives; Ethanol. In: Hardman JG, Limbird LE, Molinoff PB, et al., eds. Goodman and Gilman’s the pharmacological basis of therapeutics, 9th edn. New York: McGraw Hill, 1996;361 - 396.
. Frampton JE, Foster RH. Pregabalin: in the treatment of postherpetic neuralgia. Drugs. 2005;65:111 - 8.
. Hansten PD, Horn JR. Top 100 Drug Interactions Monographs. In: The Top 100 Drug Interactions - A guide to Patient Management. 2004 Edition. Edmonds, WA: H&H Publications; 2004:4 - 142.
. Requip® (ropinirole hydrochloride) package insert. Research Triangle Park, NC: GlaxoSmithKline; 2005 May.
. Cesamet™ (nabilone) package insert. Costa Mesa, CA: Valeant Pharmaceuticals International; 2006 May.
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