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For acute hives in a healthy adult, the maximum dosage of diphenhydramine is 300 mg per day orally, and for cetirizine, it is 10 mg per day orally.[1-2]
Diphenhydramine can be administered in doses of 25 to 50 mg orally 3 to 4 times daily, not exceeding 300 mg per day.[1]
Cetirizine is recommended at a dose of 10 mg once daily, either orally or intravenously.[2-3]
Loratadine is another option, with a maximum dosage of 10 mg per day orally.[4]
It is important to monitor for common side effects such as drowsiness, dry mouth, and dizziness, especially with diphenhydramine.[1]
Cetirizine and loratadine are generally less sedating compared to diphenhydramine but can still cause some drowsiness and fatigue.[2][4]
Additional info
When treating acute hives, the choice of antihistamine might depend on the patient's need for sedation (diphenhydramine being more sedating) and the duration of action required. Cetirizine and loratadine offer once-daily dosing which might be more convenient for some patients. It's crucial to consider the patient's overall health, presence of any renal or hepatic impairment, and any other medications they are taking due to potential drug interactions. Always consider the patient's lifestyle and preference to ensure adherence to the treatment plan.
References
Reference 1
1.
Elsevier ClinicalKey Drug Monograph
Content last updated: May 2, 2024.
Indications And Dosage
Oral dosage
Adults:
25 to 50 mg PO 3 to 4 times daily as needed. Max: 300 mg/day.
Infants, Children, and Adolescents:
1 to 1.5 mg/kg/dose (Max: 25 to 50 mg/dose) PO 3 to 4 times daily as needed. Max: 5 mg/kg/day or 300 mg/day.
Intravenous or Intramuscular dosage
Adults:
10 to 50 mg IV or IM every 4 to 6 hours, as needed. Single doses of 100 mg may be given if required. Max: 400 mg/day.
Adolescents:
25 to 50 mg/dose IV or IM every 4 to 6 hours as needed (Max: 400 mg/day).
Infants and Children:
1 to 2 mg/kg/dose (Max: 50 mg/dose) IV or IM every 4 to 8 hours as needed, up to 5 mg/kg/day (Max: 200 mg/day).
Reference 2
2.
Elsevier ClinicalKey Drug Monograph
Content last updated: May 5, 2024.
Indications And Dosage
10 mg/day PO; 10 mg/day IV. 2 drops/day per affected eye for ophthalmic solution.
Reference 3
3.
Food and Drug Administration (DailyMed).
Publish date: August 2, 2023.
Dosage And Administration Table
<table><col/><col/><tbody><tr><td valign="top" styleCode=" Botrule Toprule Lrule Rrule"/><td valign="top" styleCode=" Botrule Toprule Lrule Rrule"/></tr><tr><td valign="top" styleCode=" Botrule Toprule Lrule Rrule">Adults and children 6years and over</td><td valign="top" styleCode=" Botrule Toprule Lrule Rrule">1 tablet (5 mg) or 2 tablets (10 mg) once daily depending upon severity of symptoms; do not take more than 2 tablets (10 mg) in 24 hours.</td></tr><tr><td valign="top" styleCode=" Botrule Toprule Lrule Rrule">Adults 65years and over</td><td valign="top" styleCode=" Botrule Toprule Lrule Rrule">1 tablet (5 mg) once daily; do not take more than 1 tablet (5 mg) in 24 hours.
Dosage And Administration
DIRECTIONS Adults and children 6years and over 1 tablet (5 mg) or 2 tablets (10 mg) once daily depending upon severity of symptoms; do not take more than 2 tablets (10 mg) in 24 hours. Adults 65years and over 1 tablet (5 mg) once daily; do not take more than 1 tablet (5 mg) in 24 hours. Children under 6 years of age ask a doctor Consumers with liver or kidney disease ask a doctor
