Advertisements for clemastine (Tavist-1 - Sandoz), an ethanolamine oral antihistamine, have recently appeared on television and in major newspapers in the USA. Clemastine is an old drug (Medical Letter, 21:24, 1979) that has now become available without a prescription.

The FDA has approved Diclegis (Duchesnay), a fixed-dose, delayed-release combination of the H1-antihistamine doxylamine and the vitamin B6 analog pyridoxine, for treatment of nausea and vomiting of pregnancy in women who do not respond to conservative management. It is only available by prescription. Doxylamine and pyridoxine, both currently available over the counter, were previously available by prescription in a fixed-dose combination (Bendectin) for morning sickness. Bendectin was voluntarily withdrawn in the US in 1983 because of claims of teratogenicity that have since been...

The physiologic changes that occur with aging can affect the pharmacokinetics and pharmacodynamics of many prescription and over-the-counter drugs, increasing the likelihood of adverse effects.

Cetirizine (Zyrtec, and others) and cetirizine/pseudoephedrine (Zyrtec-D) are becoming available without a prescription this month for treatment of allergic rhinitis and urticaria in adults and children. Cetirizine is the second of the second-generation H1-antihistamines to become available over the counter. Loratadine (Claritin, and others) was the first.Cetirizine has been shown to be more effective than loratadine in suppressing histamine-induced wheals in healthy volunteers (W Carey et al. Drugs Exp Clin Res 2002; 28:243), but no well-controlled clinical trials have established that any...

With the coming of spring, direct-to-consumer (DTC) advertisements in newspapers, in magazines and on television are urging people with seasonal allergies to ask their doctors about one or another of the newer, non-sedating antihistamines.

Quzyttir (TerSera), an IV formulation of the second-generation H1-antihistamine cetirizine, has been approved by the FDA for treatment of acute urticaria in patients ≥6 months old. Oral formulations of cetirizine (Zyrtec, and others) have been for sale over the counter for years. Quzyttir is the first parenteral formulation of a second-generation H1-antihistamine to become available in the US; parenteral formulations of two first-generation H1-antihistamines, diphenhydramine (Benadryl, and others) and hydroxyzine (Vistaril, and others), have been available for many...

An FDA panel has recommended that stronger warnings about hepatotoxicity be added to the labeling for acetaminophen (www.fda.gov, search "acetaminophen hepatotoxicity").

The FDA has approved the marketing of loratadine (Claritin - Schering), a second-generation H₁-antihistamine, without a prescription. The drug was also recently approved for OTC use as Alavert (Wyeth) and other generics are expected.

Paclitaxel (Taxol - Bristol-Myers Squibb) is now available in the USA for treatment of metastatic ovarian cancer refractory to other drugs. The new drug is a natural product extracted in small amounts from the inner bark of the Western yew tree found mainly in the Pacific northwest (Taxus brevifolia). Efforts to synthesize the drug have been unsuccessful to date, but a semi-synthetic product (taxotere) prepared from the needles of European yews has shown some promise (R Pazdur et al, J Natl Cancer Inst, 89:1781, 1992), and a fungus (Taxomyces andreanae) growing on the Pacific yew was...

Nabilone (Cesamet - Lilly), a synthetic cannabinoid chemically related to tetrahydrocannabinol (THC), the main active ingredient in marijuana, was recently marketed in the USA for oral treatment of nausea and vomiting associated with cancer chemotherapy. Oral THC itself, known generically as dronabinol (Marinol), is also commercially available as an antiemetic for cancer patients (Medical Letter, 27:97, 1985). Other drugs used for this purpose include metoclopramide (Reglan - Medical Letter, 24:67, 1982), prochlorperazine (Compazine; and others), haloperidol (Haldol; and others), and...