Donepezil hydrochloride (Aricept - Eisai), a piperidine-based acetylcholinesterase inhibitor, is now being marketed for oral treatment of cognitive symptoms in patients with mild to moderate dementia due to Alzheimer's disease. Donepezil is the second drug approved for this indication; tacrine hydrochloride (Cognex), also an acetylcholinesterase inhibitor, has been available in the USA for four years (Medical Letter, 35:87, 1993).

View the Inhibitors and Inducers of CYP Enzymes, P-Glycoprotein, and Other Transporters tables

Midodrine hydrochloride (ProAmatine - Roberts), an alpha1-selective adrenergic agonist, is now available for treatment of severe symptomatic orthostatic hypotension. Other treatments for this condition include other sympathomimetics, constrictive garments, erythropoietin (Epogen; Procrit) and fludrocortisone with salt (D Robertson and TL Davis, Neurology, 45 suppl 5: S26, 1995).

Itraconazole (Sporanox - Janssen), an oral antifungal triazole that has been available in the USA since 1992 for treatment of deep fungal infections (Medical Letter, 35:7, 1993), is now being marketed for treatment of dermatophyte infections of the toenails, with or without fingernail involvement.

Use of a selective serotonin reuptake inhibitor (SSRI) is common in women taking tamoxifen (Nolvadex, and others) for breast cancer, both to treat depression and to decrease hot flashes. However, tamoxifen must be metabolized by CYP2D6 to become pharmacologically fully active (MJ Higgins et al. J Natl Compr Canc Netw 2009; 7:203), and the SSRIs fluoxetine (Prozac, and others) and paroxetine (Paxil, and others) are strong inhibitors of CYP2D6. Sertraline (Zoloft, and others) inhibits CYP2D6 to a lesser extent. Citalopram (Celexa, and others) and escitalopram (Lexapro), the 2 other SSRIs...

Colesevelam hydrochloride (Welchol - Sankyo Pharma), a nonabsorbed hydrophilic polymer that binds bile acids, has been approved by the FDA for reduction of plasma LDL cholesterol in patients with primary hypercholesterolemia.

When patents expire on brand-name drugs and generic formulations become available, patients and managed care organizations may express a preference for the lower-cost generics. Are they equivalent to the brand-name product?

Mefloquine hydrochloride (Lariam - Roche), a new antimalarial drug chemically related to quinine, has been approved by the US Food and Drug Administration (FDA) for prevention and treatment of Plasmodium falciparum and P. vivax malaria.

Older patients are especially susceptible to drug-induced cognitive impairment. They are more likely to be taking multiple drugs, to have higher blood levels of those drugs because of renal or hepatic dysfunction, and to have pre-existing cognitive problems that make it difficult to detect the role of drugs causing new symptoms or making old ones worse.

Vardenafil (Levitra -Bayer) is the second oral drug approved by the FDA for treatment of erectile dysfunction. Sildenafil (Viagra - Medical Letter 1998; 40:51), the first oral drug, has been available for 5 years. Pharmacokinetics, effectiveness, adverse effects, dosage and cost of the new drug are reviewed. Whether it offers any benefits over sildenafil is discussed.