Histaprin

Diphenhydramine · Tablet · Oral

Over the counter Histamine-1 Receptor Antagonist

Active ingredient

Active Ingredient (in each caplet) Diphenhydramine Hydrochloride 25mg

Purpose

Purpose: Antihistamine

Uses

Uses: Temporarily relieves these symptoms due to the common cold, hay fever, or other upper respiratory allergies: runny nose sneezing itching of the nose or throat itchy, watery eyes

Warnings

Warnings: Do not use with any other products containing diphenhydramine, even one used on skin

Ask a doctor before use

Ask a doctor before use if you have : trouble urinating due to enlarged prostate gland glaucoma a breathing problem such as emphysema or chronic bronchitis

Ask a doctor or pharmacist

Ask a doctor or pharmacist before use if you are taking sedatives or tranquilizers

When using this product

When using this product: drowsiness may occur avoid alcoholic beverages alcohol, sedatives and tranquilizers may increase the drowsiness effect use caution when driving a motor vehicle or operating machinery excitability may occur, especially in children

Pregnancy or breast-feeding

If pregnant or breast-feeding , ask a health professional before use.

Keep out of reach of children

Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center right away. 1-800-222-1222

Directions

Directions Do not take more than directed Adults and children 12 years of age and over: Take 1 caplet every 4 to 6 hours while symptoms persist do not take more than 6 caplets in 24 hours unless directed by a doctor Children under 12 years of age: ask a doctor

Inactive ingredients

corn starch, D&C red #27 aluminum lake, dibasic calcium phosphate dihydrate, magnesium stearate, microcrystalline cellulose, polyethylene glycol, polyvinyl alcohol, silicon dioxide, stearic acid, talc, titanium dioxide

Label text from the FDA structured product label by NorMed (revised Jan 14, 2026). Long sections are shortened; the complete label is on DailyMed.

Active ingredients

Histaprin NDC products (1)

NDCStrength & formLabelerType
50332-0150Diphenhydramine Hydrochloride 25 mg/1
Tablet
NorMedOTC MONOGRAPH DRUG

Frequently asked questions

What is Histaprin used for?

Uses: Temporarily relieves these symptoms due to the common cold, hay fever, or other upper respiratory allergies: runny nose sneezing itching of the nose or throat itchy, watery eyes

Who makes Histaprin?

Histaprin is listed by 1 labeler in the FDA NDC directory, including NorMed.