Earlier this year, the U.S. Food and Drug Administration asked pharmaceutical companies to lower the dosages of sleeping pills such as Ambien and Edluar because of reports that people were getting behind the wheel of their cars in the morning while still drowsy. Recently, the FDA pointed out that some allergy medications pose a similar risk. While it may not seem like a serious issue, drowsy driving can, in fact, lead to serious, even fatal, car accidents.
Medications such as Benadryl, Claritin and Zyrtec provide many people with the relief they need from seasonal allergies. Unfortunately, these sorts of medications - known as antihistamines - can also cause drowsiness and can even impact a person's reaction time.
The best advice is for people who take allergy medications to read the labels carefully and discuss the potential side effects with their doctors. Experts warn, too, that different brands of over the counter allergy medicines may be dosed differently. This means that while two different medications may contain the same active ingredient, one brand may have more of it. If someone is used to a particular dosage and takes another brand expecting to react to it in the same way, he could experience potentially serious side effects.
Doctors also recommend that people guard against mixing medications. Taking a sleeping pill at night and an antihistamine in the morning, for example, could lead to a dangerous interaction. Whether the drug is available over the counter or only by prescription, the label should contain information about what other medications to avoid.
Source: CBS News, “FDA: Allergy medications may make you too drowsy to drive,” Ryan Jaslow, June 1, 2013