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,...

Many patients ask their healthcare providers whether they should take vitamins. Since the last Medical Letter article on this subject, more data have become available on the benefits and risks of taking vitamins.

The US Food and Drug Administration recently approved the marketing of goserelin acetate (Zoladex - ICI Pharma), an implant for palliative treatment of advanced prostate cancer. Goserelin acetate is a synthetic decapeptide luteinizing hormone-releasing hormone (LH-RH) analog similar to leuprolide (Lupron; Lupron Depot) (Medical Letter, 27:71, 1985).

Idarubicin hydrochloride (Idamycin - Adria), an anthracycline structurally related to daunorubicin (Cerubidine, and others) and doxorubicin (Adriamycin, and others), was recently approved in the USA for treatment of acute myelogenous leukemia (AML) in adults.

Interferon β-1b (Betaseron - Berlex), an analog of human interferon β pro-duced in E. coli, may soon be approved by the US Food and Drug Administration for treatment of relapsing-remitting multiple sclerosis (MS), the most common form of the disease (G Mitchell, Med Clin North Am, 77:231, 1993).

Two portable instruments for monitoring prothrombin time have been approved by the US Food and Drug Administration (FDA). The Coumatrak (DuPont Pharma) and CoaguChek (Boehringer Mannheim Diagnostics) are marketed in the USA only for use by healthcare professionals. In Europe, however, the CoaguChek is also marketed for use by patients. A CoaguChek Plus portable system, which measures activated partial thromboplastin time (APTT) as well as prothrombin time, is also available in both Europe and the USA.

The FDA has approved three office laboratory tests for diagnosis of influenza. These tests are of special interest now because the FDA recently also approved two new drugs for treatment of influenza that must be started--to be effective--less than 48 hours after the onset of symptoms.

The FDA has approved a delayed-release oral formulation of prednisone (Rayos – Horizon Pharma). Rayos is not labeled for any specific indication, but the only published studies of the new product have been in patients with rheumatoid arthritis (RA).

The FDA has approved crofelemer (kroe fel’ e mer; Fulyzaq – Salix), a chloride channel inhibitor derived from the red sap of the South American plant Croton lechleri, for symptomatic relief of noninfectious diarrhea in patients with HIV taking antiretroviral drugs. It is the first drug approved for relief of antiretroviral-induced diarrhea and the first oral botanical drug approved by the FDA.

View the Table: GLP-1 and GIP/GLP-1 Receptor Agonists for Chronic Weight Management