What Is Triprolidine? Uses, Dosage, and What You Need to Know in 2026

Triprolidine is a first-generation antihistamine that has been used for decades to treat allergic rhinitis (hay fever), common cold symptoms, and other allergic conditions. While second-generation antihistamines have largely replaced it in clinical guidelines for ongoing allergy management, triprolidine remains in widespread use — particularly in combination with pseudoephedrine for acute cold and allergy relief. Here's everything you need to know about triprolidine in 2026.

What Is Triprolidine?

Triprolidine hydrochloride is an over-the-counter first-generation H1 antihistamine belonging to the alkylamine chemical class. It was first synthesized in the 1940s and has been available commercially since the 1950s. It works by blocking the H1 histamine receptor, preventing histamine from causing allergy symptoms like sneezing, runny nose, itchy eyes, and hives.

Triprolidine is not a controlled substance. It is available OTC for adults and children age 6 and older. Combination products with pseudoephedrine must be purchased from behind the pharmacy counter due to federal pseudoephedrine regulations — but they do not require a prescription.

What Is Triprolidine Used For?

Triprolidine is indicated for:

Seasonal and perennial allergic rhinitis (hay fever): Relief of sneezing, runny nose, nasal congestion, and itchy or watery eyes caused by allergens like pollen, dust mites, pet dander, and mold

Common cold symptoms: Used in combination with pseudoephedrine to relieve multiple cold symptoms simultaneously, including nasal congestion (pseudoephedrine) and runny nose/sneezing (triprolidine)

Urticaria (hives): Mild, uncomplicated allergic skin manifestations

Allergic conjunctivitis: Itchy, watery eyes caused by allergens

Brand Names and Available Formulations

Standalone triprolidine: Histex, Histex PD Drops, Zymine (oral solutions/syrups primarily for pediatric use); 0.938 mg/mL, 1.25 mg/5 mL

Triprolidine + Pseudoephedrine combination: Actifed (original formula, generic only in US), Aprodine, Aphedrid, Allerfrin, Genac (tablets: 60 mg/2.5 mg; syrup: 30 mg/1.25 mg per 5 mL)

Triprolidine Dosage Guide

Always follow the label directions or your doctor's instructions. General dosing guidelines:

Adults and children 12+: 2.5 mg every 4–6 hours; max 10 mg per 24 hours

Children 6–11 years: 1.25 mg every 4–6 hours; max 5 mg per 24 hours

Children 4–6 years: 0.938 mg every 4–6 hours (oral solution only; physician direction recommended)

Children 2–4 years: 0.625 mg every 4–6 hours (oral solution; only under physician direction)

Children under 2: Do not use without physician direction; FDA warns against OTC use

For combination tablets (60 mg pseudoephedrine / 2.5 mg triprolidine): Adults and children 12+ take 1 tablet every 4–6 hours; max 4 tablets per 24 hours.

How Long Does Triprolidine Take to Work?

Triprolidine is rapidly absorbed after oral administration. Therapeutic concentrations are typically achieved within 30–60 minutes of taking a dose, with relief lasting 4–8 hours. It is eliminated primarily through hepatic (liver) metabolism.

Who Should Not Take Triprolidine?

Triprolidine is contraindicated or should be used with extreme caution in:

Patients with angle-closure glaucoma (risk of acute glaucoma attack)

Patients with benign prostatic hyperplasia (BPH) or bladder-neck obstruction

Patients taking MAO inhibitors within the past 14 days

Children under 2 (or under 4 for self-medication)

Patients with severe asthma or COPD (risk of thickened secretions)

Where to Get Triprolidine in 2026

Triprolidine is available at most major pharmacies — though combination products with pseudoephedrine must be requested from behind the pharmacy counter. If you're having trouble finding it, medfinder can help locate it near you. See our full guide on how to find triprolidine in stock.