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Allergy Medications: Antihistamines
July 3, 2009 |
Antihistamines
Antihistamines have been the mainstay of allergy treatment for decades. The so-called first-generation drugs like diphenhydramine (Benadryl), brompheniramine (Dimetane, Dimetapp), and chlorpheniramine (Chlor-Trimeton) are linked to drowsiness and cognitive impairment 47 Second-generation antihistamines such as cetirizine (Zyrtec), desloratadine (Clarinex), fexofenadine (Allegra), and loratadine (Claritin) have been promoted as nonsedating. Because they were supposed to be so much safer and better tolerated than the old-fashioned drugs, many came with a very steep price tag ($2 to $3 per pill). But there is growing concern that when given in doses that are adequate to relieve allergy symptoms, even these newer compounds may cause some sedation in some patients and produce mild impairment.48 Researchers now believe that “a clear and consistent distinction between sedating and nonsedating antihistamines does not exist.”‘
What this means is that the allergy victim is truly caught on the horns of a dilemma. Suffering with allergies makes you spacey, sleepy, and irritable and can impair your ability to function. Antihistamines can also cause sedation and impair performance. If such drugs only partially control symptoms (a fairly common situation), then you may end up with the worst
Claritin used to be the most widely prescribed antihistamine on the market. When it lost patent protection, the company took it OTC. Compared to many of the older nonprescription antihistamines, loratadine is probably less likely to cause drowsiness at recommended doses. We have seen no data to suggest that it is less effective than pricier prescription antihistamines.
Side effects: Headache, sleepiness, dry mouth, fatigue, jitteriness, and stomach upset. Liver problems may be a rare adverse reaction.
Downside: More expensive than old-fashioned antihistamines. Insurance companies may deny you affordable access to drugs like Allegra now that loratadine is available OTC. Loratadine may cause sedation and impair driving in susceptible people. Do not assume you are safe behind the wheel.
Cost: Approximately $5 to $10 for a month’s supply when purchased generically in bulk. The brand-name Claritin can cost two to four times that much.
situation of all—sedation from the medicine and from the allergic condition.”
In such a confusing situation, we would normally suggest that the allergy sufferer experiment with a variety of antihistamines to try and determine which one works best and is least troublesome in terms of side effects. The difficulty is that people are notoriously bad at assessing their level of impairment. There is a warning on the label of Benadryl and many other OTC allergy medicines reminding users that “marked drowsiness may occur” and urging them to “be careful when driving a motor vehicle or operating machinery.” Such cautions are as meaningless as telling a drunk to be careful behind the wheel. In fact, researchers have reported that diphenhydramine”had a greater impact on driving than alcohol did: ,51 These scientists discovered that “drowsiness ratings were not a good predictor of impairment, suggesting that drivers cannot use drowsiness to indicate when they should not drive.”
By the way, did you know that you could be arrested for driving while impaired after taking an OTC allergy pill? If your driving skills are not up to par, an officer can give you a ticket even though you have no alcohol in your system.
So, dear reader, we have no easy answers. We would like to say, if you have allergies, do not drive, especially if you are taking antihistamines. That would be the only prudent thing. We know that some people will disobey such a suggestion, however. Some experts believe that fexofenadine (Allegra) may be one of the least sedating and safer antihistamines to take if you must drive. 52,51 Others point out that even this non-sedating antihistamine may pose problems at higher doses. 54 If driving or operating machinery is essential or if you must make important decisions, we encourage you to look for other options besides oral antihistamines.
There is now a prescription antihistamine nasal spray called azelastine (Astelin). It is fairly fast acting but has the disadvantage of requiring twice-daily nasal spritzing. Some data suggest it may be as effective as oral antihistamines. Side effects may include a bitter taste in the mouth (20 percent of patients), headache, drowsiness (11 percent of patients), nasal burning or inflammation, sore throat, dry mouth, sneezing, fatigue, and dizziness. A 1 -ounce bottle can cost $75 to $85. Not exactly a perfect solution to the problem, eh?