What is the appropriate diphenhydramine (Benadryl) dose for an adult with a glomerular filtration rate of 58 mL/min? | Rounds What is the appropriate diphenhydramine (Benadryl) dose for an adult with a glomerular filtration rate of 58 mL/min? | Rounds
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What is the appropriate diphenhydramine (Benadryl) dose for an adult with a glomerular filtration rate of 58 mL/min?

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Diphenhydramine Dosing in Adults With Estimated GFR 58 mL/min

Adult diphenhydramine dosing does not list renal dose adjustment criteria in the prescribing information. [1] For an adult with an estimated glomerular filtration rate (eGFR) of 58 mL/min, the labeled adult dose regimen is appropriate. [1]

Medication Dosing Regimen

The labeled oral adult dose of diphenhydramine is 25 to 50 mg three or four times daily. [1] The labeled nighttime sleep-aid dose is 50 mg at bedtime. [1]

Renal Function Considerations for GFR 58 mL/min

Diphenhydramine is metabolized and only a small amount is excreted unchanged in urine in the prescribing information. [1] The prescribing information does not provide a specific renal impairment dose reduction based on creatinine clearance or eGFR. [1]

Dosing Limits

The prescribing information provides maximum daily dosage guidance for pediatric use but does not provide an adult maximum daily dose in the dosing section shown. [1]

Safety Considerations Relevant to CKD Patients

Diphenhydramine is associated with sedation and anticholinergic adverse effects. [1] These effects increase risk in older adults and with CNS depressants or alcohol use. [1]

Practical Dose Selection for This Renal Function Level

The labeled regimen supports use of the standard adult dosing range of 25 to 50 mg per dose with three to four daily administrations. [1] Nighttime sleep-aid dosing is 50 mg at bedtime. [1]

Monitoring for excessive sedation, confusion, urinary retention, and hypotension is recommended when diphenhydramine is used. [1] Antihistamine adverse effects require reassessment of ongoing dosing frequency. [1]

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