Comparative Pharmacology
Head-to-head clinical analysis: BENADRYL PRESERVATIVE FREE versus DIPHEN.
Peer-Reviewed Evidence
Head-to-head clinical analysis: BENADRYL PRESERVATIVE FREE versus DIPHEN.
BENADRYL PRESERVATIVE FREE vs DIPHEN
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Diphenhydramine competitively antagonizes histamine at H1-receptors on effector cells, leading to relief of allergic symptoms. It also possesses anticholinergic, antiemetic, sedative, and local anesthetic effects.
Diphenhydramine is a first-generation antihistamine that competitively antagonizes histamine at H1 receptors. It also exhibits anticholinergic, sedative, antiemetic, and local anesthetic effects.
25-50 mg IV/IM every 4-6 hours as needed; maximum single dose 100 mg, maximum daily dose 400 mg.
50 mg IV/IM every 4 hours as needed for nausea/vomiting; 25-50 mg PO every 4-6 hours as needed for nausea/vomiting or motion sickness; 25 mg PO 3-4 times daily for vertigo; 15.6-25 mg IM/IV for antiemetic in surgery; maximum 300 mg/day.
None Documented
None Documented
Clinical Note
moderateDiphenoxylate + Torasemide
"The risk or severity of adverse effects can be increased when Diphenoxylate is combined with Torasemide."
Clinical Note
moderateDiphenoxylate + Etacrynic acid
"The risk or severity of adverse effects can be increased when Diphenoxylate is combined with Etacrynic acid."
Clinical Note
moderateDiphenoxylate + Furosemide
"The risk or severity of adverse effects can be increased when Diphenoxylate is combined with Furosemide."
Clinical Note
moderateTerminal elimination half-life: 4-8 hours (mean ~5 hours). Prolonged in hepatic impairment (up to 2-fold) and elderly (7-12 hours).
Terminal elimination half-life is 22–72 hours (mean 30–40 hours); increases with hepatic disease or enzyme inhibitors.
Primarily renal (90% as metabolites and unchanged drug); ~1% excreted in feces via bile. Unchanged diphenhydramine accounts for <5% of urinary recovery.
Primarily hepatic metabolism; renal excretion of inactive metabolites accounts for ~70% of eliminated drug; biliary/fecal excretion accounts for ~30%.
Category C
Category C
Antihistamine
Antihistamine
Diphenoxylate + Bumetanide
"The risk or severity of adverse effects can be increased when Diphenoxylate is combined with Bumetanide."