The phosphodiesterase type 5 (PDE5) inhibitor tadalafil (Cialis - Lilly) is now being promoted for once daily treatment of erectile dysfunction. Tadalafil differs from sildenafil (Viagra) and vardenafil (Levitra), the other PDE5 inhibitors marketed for erectile dysfunction in the US, in having a much longer duration of action.

In recent months, both the lay media and some medical experts have raised concerns about the effectiveness and safety of ezetimibe, a widely used drug that prevents absorption of cholesterol from the GI tract. Ezetimibe is available alone as Zetia and in combination with 10, 20, 40 and 80 mg of simvastatin (Zocor, and others) as Vytorin.

The FDA has required the manufacturer of Plavix, an antiplatelet drug used in addition to aspirin to prevent cardiovascular events in high-risk patients,1 to add a boxed warning to the package insert about the risk of a poor response to the drug in patients with genetic polymorphisms of the cytochrome P450 enzyme CYP2C19. Clopidogrel is a prodrug and CYP2C19 is mainly responsible for its bioactivation. The Medical Letter reported last year that several studies have found higher rates of cardiovascular events, including stent thrombosis, in patients with these polymorphisms taking...

Bedaquiline (bed ak' wi leen; Sirturo – Janssen), a diarylquinoline antimycobacterial, has been given accelerated approval by the FDA as an orphan drug for use in addition to other drugs for treatment of adults with multidrug-resistant pulmonary tuberculosis (MDR-TB). It is the first drug approved specifically to treat MDR-TB.

View Expanded Table: Some Conventional DMARDs for Rheumatoid Arthritis

The potassium-competitive acid blocker vonoprazan (Voquezna – Phathom), which was approved earlier for treatment of erosive esophagitis, has now been approved by the FDA for relief of heartburn associated with nonerosive gastroesophageal reflux disease (GERD) in adults. Vonoprazan is also available copackaged with amoxicillin (Voquezna Dual Pak) and with amoxicillin and clarithromycin (Voquezna Triple Pak) for treatment of Helicobacter pylori infection.

Levodopa combined with carbidopa (Sinemet) is the treatment of choice for Parkinson's disease (Medical Letter, 30:113, 1988). After prolonged treatment, however, the symptoms of the disease often become difficult to manage. The benefit from each dose becomes shorter (the 'wearing-off' effect), sudden fluctuations occur between mobility and immobility (the 'on-off' phenomenon), and abnormal involuntary movements (dyskinesias) may become frequent. The dopamine agonist bromocriptine (Parlodel) can ameliorate some of these effects. Two new drugs, pergolide (Permax - Lilly), another dopamine...

Leflunomide (Arava - Hoechst Marion Roussel), which inhibits pyrimidine synthesis, and etanercept (Enbrel - Immunex/Wyeth-Ayerst), which blocks the action of tumor necrosis factor (TNF), have been approved by the FDA for treatment of rheumatoid arthritis. A third drug, infliximab (Remicade - Centocor), which also blocks TNF and has been used to treat rheumatoid arthritis, was approved earlier for treatment of Crohn's disease. Its use in Crohn's disease will be reviewed in a future issue.

FluMist (MedImmune), the first live-attenuated and first intranasally administered influenza vaccine, has been approved by the FDA to prevent influenza in healthy people 5-49 years old. Given as a nasal spray, it stimulates immunity by viral replication in the upper respiratory tract. This vaccine apparently will be advertised directly to the public as a "needle-free" alternative to intramuscular influenza vaccine.

Vytorin, a fixed-dose combination of the cholesterol absorption inhibitor ezetimibe (Zetia - Merck/Schering Plough) and the HMG-CoA reductase inhibitor ("statin") simvastatin (Zocor - Merck), has been approved by the FDA for treatment of hypercholesterolemia. It is available as tablets containing 10 mg of ezetimibe combined with 10, 20, 40 or 80 mg of simvastatin.