7 Interactions found for:
- 3 Major
- 3 Moderate
- 1 Minor
Drug Interactions
Moderate
Benadryl
+ Hydroxyzine
The following applies to the ingredients: Diphenhydramine (found in Benadryl) and Hydroxyzine
MONITOR: Agents with anticholinergic properties (e.g., sedating antihistamines; antispasmodics; neuroleptics; phenothiazines; skeletal muscle relaxants; tricyclic antidepressants; disopyramide) may have additive effects when used in combination. Excessive parasympatholytic effects may result in paralytic ileus, hyperthermia, heat stroke, and the anticholinergic intoxication syndrome. Peripheral symptoms of intoxication commonly include mydriasis, blurred vision, flushed face, fever, dry skin and mucous membranes, tachycardia, urinary retention, and constipation. Central symptoms may include memory loss, disorientation, incoherence, hallucinations, psychosis, delirium, hyperactivity, twitching or jerking movements, stereotypy, and seizures. Central nervous system-depressant effects may also be additively or synergistically increased when these agents are combined, especially in elderly or debilitated patients. Use of neuroleptics in combination with other neuroleptics or anticholinergic agents may increase the risk of tardive dyskinesia. In addition, some neuroleptics and tricyclic antidepressants may cause prolongation of the QT interval and theoretically, concurrent use of two or more drugs that can cause QT interval prolongation may result in additive effects and increased risk of ventricular arrhythmias including torsade de pointes and sudden death.
MANAGEMENT: Caution is advised when agents with anticholinergic properties are combined, particularly in the elderly and those with underlying organic brain disease, who tend to be more sensitive to the central anticholinergic effects of these drugs and in whom toxicity symptoms may be easily overlooked. Patients should be advised to notify their physician promptly if they experience potential symptoms of anticholinergic intoxication such as abdominal pain, fever, heat intolerance, blurred vision, confusion, and/or hallucinations. Ambulatory patients should be counseled to avoid activities requiring mental alertness until they know how these agents affect them. A reduction in anticholinergic dosages may be necessary if excessive adverse effects develop.
References
- Stadnyk AN, Glezos JD "Drug-induced heat stroke." Can Med Assoc J 128 (1983): 957-9
- Zelman S, Guillan R "Heat stroke in phenothiazine-treated patients: a report of three fatalities." Am J Psychiatry 126 (1970): 1787-90
- Mann SC, Boger WP "Psychotropic drugs, summer heat and humidity, and hyperplexia: a danger restated." Am J Psychiatry 135 (1978): 1097-100
- Warnes H, Lehmann HE, Ban TA "Adynamic ileus during psychoactive medication: a report of three fatal and five severe cases." Can Med Assoc J 96 (1967): 1112-3
- Gershon S, Neubauer H, Sundland DM "Interaction between some anticholinergic agents and phenothiazines." Clin Pharmacol Ther 6 (1965): 749-56
- Sarnquist F, Larson CP Jr "Drug-induced heat stroke." Anesthesiology 39 (1973): 348-50
- Johnson AL, Hollister LE, Berger PA "The anticholinergic intoxication syndrome: diagnosis and treatment." J Clin Psychiatry 42 (1981): 313-7
- Lee BS "Possibility of hyperpyrexia with antipsychotic and anticholinergic drugs." J Clin Psychiatry 47 (1986): 571
- Forester D "Fatal drug-induced heat stroke." JACEP 7 (1978): 243-4
- Moreau A, Jones BD, Banno V "Chronic central anticholinergic toxicity in manic depressive illness mimicking dementia." Can J Psychiatry 31 (1986): 339-41
- Hvizdos AJ, Bennett JA, Wells BG, Rappaport KB, Mendel SA "Anticholinergic psychosis in a patient receiving usual doses of haloperidol." Clin Pharm 2 (1983): 174-8
- Cohen MA, Alfonso CA, Mosquera M "Development of urinary retention during treatment with clozapine and meclizine [published erratum appears in Am J Psychiatry 1994 Jun;151(6):952]." Am J Psychiatry 151 (1994): 619-20
- "Product Information. Cogentin (benztropine)." Merck & Co., Inc PROD (2001):
- Kulik AV, Wilbur R "Delirium and stereotypy from anticholinergic antiparkinson drugs." Prog Neuropsychopharmacol Biol Psychiatry 6 (1982): 75-82
- "Product Information. Artane (trihexyphenidyl)." Lederle Laboratories PROD (2001):
Drug and Food Interactions
Moderate
Hydroxyzine
+ Food
The following applies to the ingredients: Hydroxyzine
GENERALLY AVOID: Alcohol may potentiate some of the pharmacologic effects of CNS-active agents. Use in combination may result in additive central nervous system depression and/or impairment of judgment, thinking, and psychomotor skills.
MANAGEMENT: Patients receiving CNS-active agents should be warned of this interaction and advised to avoid or limit consumption of alcohol. Ambulatory patients should be counseled to avoid hazardous activities requiring complete mental alertness and motor coordination until they know how these agents affect them, and to notify their physician if they experience excessive or prolonged CNS effects that interfere with their normal activities.
References
- Warrington SJ, Ankier SI, Turner P "Evaluation of possible interactions between ethanol and trazodone or amitriptyline." Neuropsychobiology 15 (1986): 31-7
- Gilman AG, eds., Nies AS, Rall TW, Taylor P "Goodman and Gilman's the Pharmacological Basis of Therapeutics." New York, NY: Pergamon Press Inc. (1990):
- "Product Information. Fycompa (perampanel)." Eisai Inc (2012):
- "Product Information. Rexulti (brexpiprazole)." Otsuka American Pharmaceuticals Inc (2015):
Moderate
Benadryl
+ Food
The following applies to the ingredients: Diphenhydramine (found in Benadryl)
GENERALLY AVOID: Use of anticholinergic agents with alcohol may result in sufficient impairment of attention so as to render driving and operating machinery more hazardous. In addition, the potential for abuse may be increased with the combination. The mechanism of interaction is not established but may involve additive depressant effects on the central nervous system. No effect of oral propantheline or atropine on blood alcohol levels was observed in healthy volunteers when administered before ingestion of a standard ethanol load. However, one study found impairment of attention in subjects given atropine 0.5 mg or glycopyrrolate 1 mg in combination with alcohol.
MANAGEMENT: Alcohol should generally be avoided during therapy with anticholinergic agents. Patients should be counseled to avoid activities requiring mental alertness until they know how these agents affect them.
References
- Linnoila M "Drug effects on psychomotor skills related to driving: interaction of atropine, glycopyrrhonium and alcohol." Eur J Clin Pharmacol 6 (1973): 107-12
Drug and Pregnancy Interactions
Major
Hydroxyzine
+ Pregnancy
The following applies to the ingredients: Hydroxyzine
Use is contraindicated.
US FDA pregnancy category: Not Assigned.
Risk Summary: There are limited data available on use of this drug in early pregnancy to inform of a drug-related risk.
Comments:
-Some authorities state that use is contraindicated during early pregnancy.
-This drug crosses the placental barrier, which may lead to higher fetal than maternal concentrations.
-If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential harm to the fetus.
-Reports in neonates exposed during late pregnancy and/or labor and delivery included central nervous system (CNS) depression, clonic movements, extrapyramidal symptoms, hypotension, movement disorders, neonatal hypoxic conditions, and/or urinary retention.
Animal studies have revealed evidence of fetal abnormalities at doses substantially above the human therapeutic range. There are no controlled data in human pregnancy.
US FDA pregnancy category Not Assigned: The US FDA has amended the pregnancy labeling rule for prescription drug products to require labeling that includes a summary of risk, a discussion of the data supporting that summary, and relevant information to help health care providers make prescribing decisions and counsel women about the use of drugs during pregnancy. Pregnancy categories A, B, C, D and X are being phased out.
References
- "Product Information. Vistaril (hydroxyzine)." Pfizer U.S. Pharmaceuticals PROD (2001):
- "Product Information. Atarax (hydroxyzine)." Pfizer U.S. Pharmaceuticals PROD (2001):
- Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
Minor
Benadryl
+ Pregnancy
The following applies to the ingredients: Diphenhydramine (found in Benadryl)
Use is recommended only if clearly needed and the benefit outweighs the risk.
AU TGA pregnancy category: A
US FDA pregnancy category: B
Comment:
-Exposure during the third trimester may result in adverse reactions in premature infants and neonates.
Animal models have failed to reveal evidence of impaired fertility or fetal harm at doses up to 5 times the human dose. There are no controlled data in human pregnancy.
AU TGA pregnancy category A: Drugs which have been taken by a large number of pregnant women and women of childbearing age without any proven increase in the frequency of malformations or other direct or indirect harmful effects on the fetus having been observed.
US FDA pregnancy category B: Animal reproduction studies have failed to demonstrate a risk to the fetus and there are no adequate and well-controlled studies in pregnant women.
References
- "Product Information. Benadryl (diphenhydramine)." Parke-Davis PROD (2002):
- "Product Information. Benadryl Children's Allergy Fastmelt (diphenhydrAMINE)." Pfizer U.S. Pharmaceuticals Group (2022):
- Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
- Cerner Multum, Inc. "Australian Product Information." O 0
- "Product Information. DiphenhydrAMINE Hydrochloride (diphenhydramine)." West-Ward Pharmaceuticals Corporation (previously Roxane Laboratories Inc) (2019):
Drug and Breastfeeding Interactions
Major
Benadryl
+ Breastfeeding
The following applies to the ingredients: Diphenhydramine (found in Benadryl)
Use is not recommended.
-According to some authorities: Use is contraindicated.
Excreted into human milk: Yes
Comments:
-The effects in the nursing infant are unknown.
-This drug may affect milk production, especially at high doses given early in the postpartum period and/or when used concomitantly with a sympathomimetic drug.
References
- "Product Information. Benadryl (diphenhydramine)." Parke-Davis PROD (2002):
- "Product Information. Benadryl Children's Allergy Fastmelt (diphenhydrAMINE)." Pfizer U.S. Pharmaceuticals Group (2022):
- Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
- Cerner Multum, Inc. "Australian Product Information." O 0
- United States National Library of Medicine "Toxnet. Toxicology Data Network. http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT" (2013):
Major
Hydroxyzine
+ Breastfeeding
The following applies to the ingredients: Hydroxyzine
Use is not recommended, and a decision should be made to discontinue breastfeeding or discontinue the drug, taking into account the importance of the drug to the mother.
Excreted into human milk: Yes (cetirizine [main metabolite]); Unknown (parent drug)
Excreted into animal milk: No data (parent drug)
Comments:
-Some authorities state that use is contraindicated.
-This drug may be excreted into breast milk.
-Serious side effects have been reported in breastfed newborns/infants.
-Some experts state that healthcare providers should consider switching treatment to alternative agents (e.g., desloratadine, fexofenadine, loratadine), especially in breastfed newborn or preterm infants.
References
- "Product Information. Vistaril (hydroxyzine)." Pfizer U.S. Pharmaceuticals PROD (2001):
- "Product Information. Atarax (hydroxyzine)." Pfizer U.S. Pharmaceuticals PROD (2001):
- Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
- United States National Library of Medicine "Toxnet. Toxicology Data Network. http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT" (2013):
- Briggs GG, Freeman RK. "Drugs in Pregnancy and Lactation." Philadelphia, PA: Wolters Kluwer Health (2015):
Therapeutic Duplication Warnings
Warning
Antihistamines
The following applies to: Benadryl (diphenhydramine), Hydroxyzine
The recommended maximum number of medicines in the 'antihistamines' category to be taken concurrently is usually one. Your list includes two medicines.
Therapeutic duplication is the use of more than one medicine from the same drug category or therapeutic class to treat the same condition. This can be intentional in cases where drugs with similar actions are used together for demonstrated therapeutic benefit. It can also be unintentional in cases where a patient has been treated by more than one doctor, or had prescriptions filled at more than one pharmacy, and can have potentially adverse consequences.
Switch to: Consumer Interactions
Drug Interaction Classification | |
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These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication. |
|
Major | Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit. |
Moderate | Moderately clinically significant. Usually avoid combinations; use it only under special circumstances. |
Minor | Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan. |
Unknown | No interaction information available. |
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