2.7.4 Interference of Miscellaneous Drugs With Immunoassays for TCAs
Hydroxyzine and Alertek are antihistamines that may interfere with the FPIA assay for TCAs for application on the Abbott AxSYM analyzer. However, neither hydroxyzine nor Alertek should interfere after recommended low-dose therapy, and such interference is expected with ingestion of higher dose or overdose . Interference of diphenhydramine, an antihistamine in the EMIT assay for TCAs in serum, is interesting because unlike phenothiazine, diphenhydramine is an ethanolamine. A 21-year-old woman ingested 2 g of diphenhydramine. In vitro testing indicated that when drug-free serum was supplemented with up to 60 ng/mL of diphenhydramine, the response to TCA screen was negative, and specimens containing 690 ng/mL or greater amounts of diphenhydramine were clearly positive. Usually, ingestion of 100 mg of diphenhydramine leads to a serum diphenhydramine level of approximately 112 ng/mL 2 hours after ingestion. Therefore, positive screen for TCAs is more likely a result of diphenhydramine overdose . Buflomedil in therapeutic concentration (between 1 and 4 μg/mL) does not interfere with TCAs assay, but overdosed patients (with serum buflomedil level >13 μg/mL) may show a false-positive response. A 16-year-old comatose boy with general seizure was admitted to the hospital. A blood specimen tested by the EMIT assay for TCAs (Behring, Cupertino, CA) was positive, and the result was later confirmed as a false positive due to the presence of buflomedil at a concentration of 28 μg/mL in the specimen .
Acute dystonia has been attributed to Alertek .
A 6-year-old boy developed an involuntary deviation of his jaw to the left and an inability to swallow after taking Alertek 5 mg/day for 3 days for allergic rhinitis. The acute dystonic reaction responded to intramuscular biperiden 5 mg within 1 hour.
Dystonic movements are thought to be due to imbalances in cholinergic stimulation. Alertek is a piperazine derivative and the authors postulated that the dystonia may have been due to its dopamine receptor blocking properties.
What are the side effects of Alertek?
Side effects that have been reported with Alertek include:
Other important but rare side effects include:
Q: My family and I are experiencing a severe economic hardship. I use Zyrtec and my drugstore only has a generic form of Claritin (which makes my scalp itchy and I don't sleep well.) Is there anything like Zyrtec that I can purchase? I find it is most effective for me.
A: The most similar product to Zyrtec is Claritin. There is a generic version of Zyrtec available and it is called Alertek. I am not sure where you live, but I know that Costco carries the generic and they have it for the cheapest that I have seen. Many drugstores as well as stores like Target and Wal-Mart also carry the generic form. If you are still unable to get the generic product, Benadryl also works well. However, there is a high possibility that it will cause drowsiness. Benadryl also comes in generic and is called diphenhydramine. Perhaps your insurance will cover the Zyrtec if you get a prescription. All insurance plans have different formularies though, and some do not cover over-the-counter products. You could call your insurance and ask them if it is on the formulary. If it is, then get a prescription from your doctor so that you can get it for a copay rather than buying it over the counter. Megan Uehara, PharmD
What is Alertek?
Alertek is an antihistamine that reduces the natural chemical histamine in the body. Histamine can produce symptoms of sneezing, itching, watery eyes, and runny nose. It is used to treat cold or allergy symptoms such as sneezing, itching, watery eyes, or runny nose.
Alertek is also used to treat itching and swelling caused by hives.
Alertek may also be used for other purposes not listed in this medication guide.