The 2006 Medical Letter article on the then-new varicella-zoster vaccine concluded that Zostavax appears to be safe and effective in protecting patients ≥60 years old against herpes zoster and postherpetic neuralgia, especially in reducing the severity and duration of the disease.1 Some new information has recently become available.CLINICAL STUDIES — A Veterans Administration randomized, double-blind trial enrolled more than 38,000 patients ≥60 years old and followed them for a mean of 3.4 years after administration of Zostavax or placebo. Since the efficacy of the vaccine had been...

In recent years, many women have become concerned about the safety of pharmaceutical replacement hormones for treatment of menopausal symptoms. “Bioidentical” hormone preparations, which are not approved by the FDA, are heavily promoted in popular books and on TV as alternatives; these are derivatives of soy or plant extracts, chemically modified to be structurally identical to endogenous hormones. Most FDA-approved single-entity hormones are also derivatives of soy or plant extracts and are structurally identical to hormones produced by the ovary.

The FDA has approved Cologuard Plus (Exact Sciences), a new at-home multitarget stool DNA test, for colorectal cancer (CRC) screening in average-risk adults ≥45 years old. Cologuard, the first FDA-approved multitarget stool DNA test, has been available since 2014.

Sexual complaints related to desire, arousal, orgasm and painful intercourse are common in women. Since the last Medical Letter article on this subject, some new information has become available.

The gram-positive anaerobic bacillus Clostridium difficile is the most common identifiable cause of antibiotic-associated diarrhea. The antibiotics most often implicated have been ampicillin, second and third generation cephalosporins, clindamycin and fluoroquinolones. The emergence in recent years of a new, more toxic epidemic strain (BI/NAP1), possibly related to widespread use of fluoroquinolones, has caused a marked increase in the incidence and severity of C. difficile-associated disease (CDAD).

Use of a proton pump inhibitor (PPI) to protect against gastrointestinal (GI) bleeding in patients taking the antiplatelet agent clopidogrel (Plavix) may interfere with the activation of clopidogrel and diminish its antiplatelet effect, increasing the risk of cardiovascular events.1 A randomized, placebo-controlled trial (COGENT) has found that use of the PPI omeprazole in patients taking clopidogrel in addition to aspirin decreased the incidence of GI bleeding without increasing the risk of a cardiovascular event, but the number of cardiovascular events was small and the formulation of...

A new enteric-coated delayed-release formulation of risedronate (Atelvia – Warner Chilcott) has been approved by the FDA for treatment of postmenopausal osteoporosis. Unlike immediate-release risedronate (Actonel) and all other oral bisphosphonates, which must be taken after an overnight fast and at least 30 minutes before eating breakfast, the new formulation is taken immediately after breakfast with at least 4 ounces of water. Then the patient must remain upright for at least 30 minutes.CLINICAL TRIAL — Approval of Atelvia was based on a 52-week non-inferiority study in more than 900...

A randomized, placebo-controlled trial evaluating the addition of the direct renin inhibitor aliskiren (Tekturna – Novartis) to an angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) in 8606 patients with type 2 diabetes and renal impairment (ALTITUDE) was terminated prematurely by the manufacturer because the combined incidence of cardiovascular and renal events was higher in patients who received aliskiren than in those who received placebo.1Combining two different types of drugs that block the renin angiotensin system in patients at high-risk for...

The FDA has approved a new extended-release capsule formulation of topiramate (Qudexy XR – Upsher Smith), which can be opened and sprinkled on food for patients who have difficulty swallowing tablets or capsules, for treatment of epilepsy. Qudexy XR was marketed as a branded drug in March 2014 and as a generic drug four months later. An earlier extended-release formulation (Trokendi XR) must be swallowed whole.Trokendi XR is approved for initial monotherapy in patients ≥10 years old with partial-onset seizures or primary generalized tonic-clonic seizures and for adjunctive therapy in...

In 2007, an FDA advisory committee asked that placebo-controlled, dose-ranging trials be conducted to establish the efficacy of the oral decongestant phenylephrine (Sudafed PE, and others), which is sold over the counter (OTC) as a single agent and in combination with other drugs for treatment of cold and allergy symptoms. Phenylephrine replaced pseudoephedrine (Sudafed, and others) in many OTC formulations when access to pseudoephedrine-containing products was restricted in an effort to reduce their use in the synthesis of methamphetamine.CLINICAL STUDIES — In a randomized, open-label,...