Antihistamines has 26 known drug interactions based on U.S. FDA drug labeling data. 6 are classified as major interactions requiring close medical supervision. Notable interactions include combinations with Droperidol, Epinephrine, Lorazepam. Patients taking Antihistamines should inform their healthcare provider of all current medications — including over-the-counter drugs and supplements — to avoid potentially harmful combinations. Data sourced from OpenFDA and the NIH National Library of Medicine.
- Total
- 26
- Major
- 6
- Moderate
- 20
Major (6)
- Antihistamines + Droperidol— Potential pharmacodynamic interaction; combined QT prolongation may precipitate arrhythmias.
- Antihistamines + Epinephrine— Potentiate arrhythmogenic effects of epinephrine; observe carefully for cardiac arrhythmias.
- Antihistamines + Lorazepam— Produces increased CNS-depressant effects including respiratory depression and sedation.
- Antihistamines + Pentobarbital Sodium— Concomitant use may produce additive CNS depressant effects.
- Antihistamines + Phenobarbital Sodium— Concomitant use of antihistamines with barbiturates may produce additive central nervous system depressant effects.
- Antihistamines + Temazepam— Produces additive CNS-depressant effects when co-administered with temazepam.
Moderate (20)
- Antihistamines + Alprazolam Odt C-Iv— Produce additive CNS depressant effects when coadministered with alprazolam.
- Antihistamines + Amphetamine Sulfate— Amphetamines may counteract the sedative effects of antihistamines.
- Antihistamines + Dextroamphetamine Saccharate And Amphetamine Aspartate And Dextroamphetamine Sulfate And Amphetamine Sulfate— Amphetamines may counteract the sedative effect of antihistamines.
- Antihistamines + Dextroamphetamine Sulfate— Amphetamines may counteract the sedative effects of antihistamines.
- Antihistamines + Diazepam— May potentiate or be potentiated by diazepam action. Careful consideration should be given when combining.
- Antihistamines + Dicyclomine Hydrochloride— May increase certain actions or side effects of anticholinergic drugs including dicyclomine hydrochloride.
- Antihistamines + Diphenoxylate Hydrochloride And Atropine Sulfate— May potentiate CNS depressant effects of diphenoxylate hydrochloride and atropine sulfate. Monitor for CNS adverse react…
- Antihistamines + Epinephrine In Sodium Chloride— Potentiate epinephrine effects and increase arrhythmogenic potential.
- Antihistamines + Estazolam— May potentiate the action of estazolam; careful consideration of CNS effects needed.
- Antihistamines + Flurazepam Hydrochloride— Produces additive CNS depressant effects. Downward dose adjustment may be necessary.
- Antihistamines + Heparin Sodium— May partially counteract the anticoagulant action of heparin. Careful monitoring recommended.
- Antihistamines + Histamine— Lessen the skin test wheal and erythema responses elicited by histamine. Should be discontinued at least 5 days before s…
- Antihistamines + Hyaluronidase— Large doses of antihistamines may require larger amounts of hyaluronidase for equivalent dispersing effect; these drugs …
- Antihistamines + Hyaluronidase, Ovine— Large doses may require larger amounts of hyaluronidase for equivalent dispersing effect; tissues become partly resistan…
- Antihistamines + Hydrocodone Bitartrate And Acetaminophen— Concomitant use may exhibit additive CNS depression; dose of one or both agents should be reduced.
- Antihistamines + Hyoscyamine Sulfate— Some antihistamines may cause additive adverse effects from cholinergic blockade when combined with hyoscyamine sulfate.
- Antihistamines + Nabilone— Additive or super-additive tachycardia, drowsiness, and CNS depression reported with concurrent use.
- Antihistamines + Phenobarbital— Concomitant use of antihistamines with phenobarbital may produce additive CNS depressant effects.
- Antihistamines + Quazepam— Produces additive CNS depressant effects. Downward dose adjustment may be necessary.
- Antihistamines + Thalidomide— Antihistamines concomitantly with thalidomide may cause additive sedative effect and should be avoided.