Vilazodone (Viibryd – Forest), a selective serotonin reuptake inhibitor (SSRI) and partial 5-HT_1A receptor agonist, has been approved by the FDA for treatment of depression. It has been claimed to have no sexual side effects and not to cause weight gain.

A selective serotonin reuptake inhibitor (SSRI) is generally used for initial treatment of major depressive disorder (MDD). A serotonin-norepinephrine reuptake inhibitor (SNRI), bupropion (Wellbutrin SR, and others), and mirtazapine (Remeron, and others) are reasonable alternatives. Improvement in symptoms can occur within the first two weeks of treatment with these drugs, but a substantial benefit may not be achieved for 4-8 weeks.

The enzyme alpha-galactosidase (Beano - AkPharma), derived from a mold and classified as a food, is sold without presecription in pharmacies and food stores. The manufacturer recommends taking the anzyme to decrease intestinal gas producted by eating the high-fiber diets now widely recommended in the USA.

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

Changes caused by one drug in the absorption, distribution, metabolism or excretion of another may lead to a pharmacokinetic adverse drug interaction (DN Juurlink et al, JAMA 2003; 289:1652). Additive drug interactions, such as vasodilation caused by both sildenafil (Viagra) and nitrates, can also have adverse effects.

The ability of grapefruit juice to increase serum concentrations of drugs was first discovered during a study of the effect of ethanol on felodipine (Plendil) pharmacokinetics. Double-strength grapefruit juice used to disguise the taste of ethanol resulted in higher than expected serum concentrations of felodipine (DG Bailey et al, Clin Invest Med 1989; 12:357).

Duloxetine hydrochloride (Cymbalta - Lilly), a selective serotonin and norepinephrine reuptake inhibitor (SNRI), has been approved by the FDA for treatment of major depressive disorder in adults, and more recently for diabetic peripheral neuropathy as well. The Medical Letter will review its role in diabetic neuropathy in a future issue.

Atovaquone (Mepron - Burroughs Wellcome), a hydroxynaphthoquinone, was recently approved by the US Food and Drug Administration (FDA) for oral treatment of mild to moderate Pneumocystis carinii pneumonia (PCP) in patients who cannot tolerate trimethoprim-sulfamethoxazole (Septra, Bactrim, and others). PCP is a common opportunistic infection and frequent cause of death in patients with AIDS.

Anxiety disorders (generalized anxiety disorder, panic disorder, social anxiety disorder, and various phobias) are the most common form of psychiatric illness. They can be treated effectively with cognitive behavioral therapy (CBT) and/or pharmacotherapy.

Augmentation with a second-generation (atypical) antipsychotic is a treatment option for patients with major depressive disorder (MDD) whose symptoms persist following antidepressant monotherapy. Aripiprazole (Abilify), olanzapine in a fixed-dose combination with fluoxetine (Symbyax), and extended-release quetiapine (Seroquel XR) have been approved by the FDA for such use.