Little to none in most people and moderate in some people
Chlorpheniramine
Moderate
Some
Clemastine
Strong
Moderate
Desloratadine
Few to none
Little to none
Diphenhydramine
Strong
Extreme
Fexofenadine
Few to none
Little to none
Loratadine
Few to none
Little to none
Prescription
Acrivastine‡
Few to none
Little to none
Azelastine
Few to none
Some
Cyproheptadine
Moderate
Some
Dexchlorpheniramine
Moderate
Some
Hydroxyzine
Moderate
Extreme
Levocetirizine
Few to none
Little to none
Mizolastine
Few to none
Little to none
Promethazine
Strong
Extreme
* Anticholinergic effects include dry mouth, blurred vision, constipation, difficulty with urination, confusion, and light-headedness (particularly after a person stands up). Older people are particularly susceptible to these effects.
† The degree of drowsiness varies, depending on the dose, other active ingredients in the formulation (as in formulations that contain a decongestant plus an antihistamine), and the person.
‡ Acrivastine is available only in combination with pseudoephedrine (a decongestant). The combination is taken by mouth.