Since the last Medical Letter article on glucosamine for osteoarthritis (vol.39, page 91, September 26, 1997), more data have become available. Glucosamine is available in US pharmacies and health food stores as sulfate, hydrochloride or n-acetyl salt.

Since the last Medical Letter review of cephalosporin antibiotics (volume 25, page 57, 1983), many new cephalosporins have become available in the USA.

Tiopronin (Thiola - Mission), a thiol compound (mercaptopropionyl glycine) that solubilizes cystine by reacting with it to form a mixed disulfide, is now available in the USA for treatment of refractory cystinuria.

Propofol (Diprivan - Stuart), a new intravenous (IV) sedative-hypnotic, was recently marketed in the USA for induction of anesthesia, or for maintenance of general anesthesia as part of a balanced anesthesia regimen. Older drugs used in a similar way include thiopental (Pentothal; and others) and midazolam (Versed).

Ablation of the globus pallidus, an old treatment for Parkinsons disease, is being tried again, using more refined stereotactic techniques, improved brain imaging and new methods for recording neuronal activity (CW Olanow, Ann Neurol, 40:341, September 1996).

Shock-wave generators like those now widely used to disintegrate urinary tract stones (Medical Letter, 27:72, 1985) have recently also been tried for treatment of radiolucent gallbladder stones. Three different types of lithotripsy devices, manufactured by at least eight different companies, are being used to treat gallbladder stones in multicenter trials in many locations in the USA. None of these devices has been approved for marketing by the US Food and Drug Administration.

Gabapentin (Neurontin - Parke-Davis), a cyclohexane acetic acid derivative, has been approved by the US Food and Drug Administration for use in addition to other antiepileptic drugs in patients with partial (focal) seizures with or without secondary generalization. Since this diagnostic category includes the largest number of patients with intractable epilepsy, new drugs with antiepileptic activity are generally tried first for this indication.

Implanted devices that monitor cardiac rhythm and can recognize and treat ventricular tachycardia or ventricular fibrillation are now widely used in the USA and other countries. Implantable cardioverter/defibrillators (ICDs) marketed here include the Ventak P and PRX (Cardiac Pacemakers, Inc., St. Paul, MN), the PCD (Medtronic, Minneapolis, MN), and the Cadence (Ventritex, Sunnyvale, CA) (JG Porterfield et al, Am J Cardiol, 72:301, 1993).

Metformin (Glucophage - Bristol-Myers Squibb), a hypoglycemic agent, was recently marketed in the USA for oral treatment of patients with non-insulin-dependent diabetes mellitus (NIDDM) not adequately controlled by diet alone. Previously marketed in more than ninety countries, including Canada, metformin (dimethylbiguanide) is chemically related to phenformin (phenylethylbiguanide), which was withdrawn from the US market in 1976 because it caused a high incidence of lactic acidosis. In approving metformin, the US Food and Drug Administration stipulated that a post-marketing controlled...

Nalmefene (Revex - Ohmeda), an i methylene analog of naltrexone (Trexan), is a long-acting opioid antagonist that has been approved by the US Food and Drug Administration for reversal of postoperative opioid drug effects, including respiratory depression, sedation and hypotension and for management of known or suspected opioid overdose in the emergency department. The only other opioid antagonists available in the USA are naloxone (Narcan), which is also injectable but has a short duration of action, and naltrexone, which has a long duration of action but is marketed only for oral...