Many prescriptions for eye drops call for instillation of 1-2 drops. But Medical Letter consultants in ophthalmology seem to agree that all eye drops should generally be given in doses of only one drop. The volume of a single drop can vary with the viscosity of the solution, the design of the dropper, and patient technique. The average volume of a drop is 35-50 microliters, but can be as high as 75 microliters. An eye brimming with fluid holds 30 microliters at best, so even one drop is often an overdose. A second either washes out the first or increases the possibility of systemic toxicity,...

The FDA has approved icatibant (Firazyr – Shire), a selective bradykinin B2 receptor antagonist, for treatment of acute attacks of hereditary angioedema (HAE). HAE is a rare autosomal dominant disorder (estimated prevalence 1:10,000-50,000) in which patients experience recurrent and frequently unpredictable attacks of angioedema lasting 2-5 days, typically involving the extremities, gastrointestinal tract, genitalia, face, oropharynx or larynx. Laryngeal edema may be life-threatening. HAE is usually caused by a mutation of the C1-inhibitor (C1-INH) gene. C1-INH is a serine proteinase...

The oral retinoid isotretinoin (Accutane, and others) is the most effective drug available for treatment of acne.1 The FDA has recently approved a new oral isotretinoin product (Absorica – Cipher/Ranbaxy) for treatment of severe, recalcitrant nodular acne.Isotretinoin can completely clear severe nodulocystic lesions, in some cases leading to remission that can persist for years after treatment is stopped. Mucocutaneous adverse effects include dry skin, dry eye, epistaxis, nasopharyngitis, cheilitis, alopecia, eczema, skin fragility and photosensitivity. Musculoskeletal symptoms,...

Mitoxantrone (Novantrone - Lederle), a synthetic anthracene related to the anthracyclines doxorubicin (Adriamycin) and daunorubicin (Cerubidine), has now been marketed in the USA to be used in combination with other drugs for initial treatment of acute nonlymphocytic leukemia in adults.

Nizatidine (Axid - Lilly), a new H2-receptor antagonist similar to cimetidine (Tagamet), ranitidine (Zantac) and famotidine (Pepcid), was recently approved by the US Food and Drug Administration for treatment of active duodenal ulcer and for maintenance therapy after healing. Cimetidine, ranitidine and famotidine are also approved for treatment of pathological hypersecretory conditions such as Zollinger- Ellison syndrome; cimetidine is approved in addition for treatment of gastric ulcers.

Repaglinide (Prandin - Novo Nordisk) is a new oral glucose-lowering agent for treating type 2 diabetes (formerly called non-insulin-dependent diabetes mellitus or NIDDM). It has been approved by the FDA for monotherapy or for use in combination with metformin.

Dofetilide (Tikosyn - Pfizer), a new methanesulfonamide antiarrhythmic drug, has recently been marketed for oral treatment of atrial fibrillation and flutter.

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.

Entecavir (Baraclude - Bristol-Myers Squibb), a nucleoside analog, has been approved by the FDA for treatment of adults with active chronic hepatitis B virus (HBV) infection.

Diclofenac epolamine patch 1.3% (Flector Patch - Alpharma), a topical formulation of the nonsteroidal anti-inflammatory drug (NSAID) diclofenac, has been approved by the FDA for topical treatment of acute pain due to minor strains, sprains and contusions. It is the first topical NSAID patch approved in the US. A diclofenac patch has been used in Europe since 1993. Diclofenac sodium (Voltaren, and others) is available in the US as an oral tablet, in a 1% gel for treatment of osteoarthritis (to be reviewed in a future issue), in a 3% gel (Solaraze) for treatment of actinic keratoses, and in an...