Wednesday, November 28, 2007

Zyrtechnicality

Near the beginning of the month, the FDA approved Zyrtec-D for over-the-counter sale in the U.S.

Rx-to-OTC conversions are always a matter of great interest for pharmacists and patients alike. Prilosec OTC floated around the FDA for a long time because the FDA was uncertain as how to to label it for patient use, eventually settling on the current information. And one of the other big non-drowsy antihistamines on the market, Claritin, was actually moved to OTC as a result of a petition by insurance company WellPoint; apparently, they got tired of paying for it. Prescription antihistamines are a huge portion of the pharmaceutical market share, totaling over $4.3 billion in 2001.The price of Claritin dropped over 70% after becoming OTC, and generic versions soon followed. Zyrtec's patent supposedly expires this December, so we may see generic versions sometime soon.

So what's the big deal?

First, for what it's worth, the U.S. is kind of behind the curve on this. OTC Zyrtec has been available in Canada for a while now under the brand name Reactine.

Second, most comparative studies suggest there is no clinical difference between newer antihistamines, though side-effects may vary somewhat. Some other studies say one or the other is better; many patients I talk to swear that Claritin is ineffective but that Zyrtec or Allergra works wonders. Aside from patient preference, the only major difference between these drugs is cost. And while the availability of Zyrtec as a competitor might drive down the cost of Claritin, generics have already done that considerably. I purchased 240 generic loratadine (Claritin) tablets last spring for about $30, which is what my insurance company wanted me to pay for prescription Zyrtec each month (retail price being something like $74). Eight months of therapy for the price of one. Not bad.

As an aside, it's kind of weird that only Zyrtec-D is going over the counter. Zyrtec-D, like its cousin Claritin-D, contains both an antihistamine (cetirizine, the generic name for Zyrtec) and the popular decongestant pseudoephedrine (PSE), well-known as being the primary ingredient in methamphetamine production. I expect "plain" Zyrtec to follow eventually, and this has little significance, but it's just an observation. Strictly speaking, all the studies I've cited were done with antihistamines alone, but since both products are available in combination with PSE, the comparisons are still valid. While both antihistamines may offer better relief to stuffy nose sufferers across the world when combined with PSE, the effect of PSE isn't going to change significantly by being paired with an antihistamine, so comparing the antihistamines directly should be sufficient. It is worth noting that Zyrtec theoretically causes slightly more drowsiness than Claritin, but it's conceivable that the mild stimulant effects of PSE will counteract that. Maybe that's the reason plain Zyrtec isn't going OTC yet. Who knows.

One of the pharmacoeconomic impacts of insurance companies pushing Claritin OTC back in 2002 is that many state Medicaid programs stopped paying for non-sedating antihistamines because patients could now get them over-the-counter. Medicaid patients who found Claritin ineffective or whose physicians prescribed other drugs were frequently out of luck, and at least a few patients were probably still unable to afford Claritin, leaving them totally out to dry. It's actually pretty likely that, at least initially, consumers will pay more for Zyrtec-D when it goes over-the-counter than they do now. Insurance companies, conversely, will save money by not reimbursing patient costs for the drug. The price for uninsured patients should drop sharply, though this doesn't necessarily mean Zyrtec-D will be the best deal available. Practically speaking, Rx-to-OTC switches tend to make self-treatment more convenient and increase patient access to medication at the drawback of increased costs for all but the uninsured. Where is that money going? Insurance premiums are still on the rise; I'll believe that making Zyrtec OTC will reduce premiums by lowering the expenses of insurance companies when I see it happen with my own eyes.

Expect to see a lot of advertising for "new" Zyrtec-D, now available OTC. Don't expect it to revolutionize the self-treatment of allergies. At best, maybe the "antihistamine wars" will make it cheaper for all of us to keep from sneezing around cats.

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