By Lu-Ann Murdoch
A VACCINE FOR LYME DISEASE
SmithKline Beecham has introduced LYMErix, a recombinant Lyme disease vaccine. The product is indicated for active immunization against Lyme disease and asymptomatic infection caused by strains of Borrelia burgdorferi which are endemic to the North American continent. Endemic areas include the Northeastern and Midwestern states of the U.S., and the Long Point, Ontario area of Lake Erie.
B. burgdorferi, the bacterium which causes Lyme disease, is transmitted by the Ioxdes tick. Administration of Lyme disease vaccine results in the formation of antibodies to proteins on the outer surface of B. burgdorferi organisms. When an infected tick bites a human who has been vaccinated with the Lyme disease vaccine, the vaccine-induced antibodies interact with the B. burgdorferi organisms and prevent their transmission.
The vaccine is indicated for persons 15 years of age and older who are at risk of infection from Lyme disease. This includes people who work outdoors or participate in recreational activities in grassy or wooded areas where Lyme disease is endemic. Pet owners (particularly in endemic areas) and people who have a prior history of B. burgdorferi infection should also be considered for immunization.
Lyme disease vaccination consists of a series of three doses. A dosage of 30 µg/0.5 mL is administered by intramuscular injection into the deltoid area at 0, 1 and 12 months. After the three-dose series, the efficacy rate against Lyme disease has ranged from 82-90 per cent. Sixty per cent of people are protected after two doses.
The main side effects associated with Lyme disease vaccination include injection site soreness, redness and/or swelling, as well as fatigue, arthralgia and rash. Reactions are usually mild to moderate in nature, and are limited in duration.
The Lyme disease vaccine is a suspension, and must be shaken well before administration. It should be stored under refrigeration.
REGRANEX FOR DIABETIC ULCERS
Janssen-Ortho has launchedRegranex (becaplermin 0.01%) topical gel. The product is used to promote the healing of full-thickness, lower extremity ulcers in patients with diabetes. Becaplermin is a recombinant human platelet-derived growth factor. It acts similarly to naturally derived growth factor in that it promotes the chemotactic recruitment and proliferation of cells involved in wound repair.
When compared to the use of placebo gel, therapy with becaplermin gel increases the incidence of complete healing by about 40 per cent, and decreases the time to complete ulcer healing by about 30 per cent. It seems to be particularly effective for ulcers with an area (length multiplied by width) of <7 cm2.
Becaplermin gel should be used once daily. It is applied (using a tongue depressor or cotton swab) as a thin layer to the entire ulcerated area. The area is then covered with a dressing that maintains a moist wound-healing environment. Prior to the next application, the wound should be rinsed gently with saline to remove residual gel.
Becaplermin therapy is intended to be combined with good ulcer care, including initial debridement, pressure relief, moist dressings, systemic treatment of wound infection (if present) and additional debridement, as needed. Therapy should be reassessed if the ulcer has not decreased in size by approximately 30 per cent after 10 weeks, or if complete healing has not occurred within 20 weeks.
To date, the side effects reported with becaplermin gel have been similar to that of placebo gel. Erythema around the wound has been noted in about two per cent of patients.
Becaplermin gel should be stored under refrigeration.
OTHER NEW PRODUCTS
Novopharm has introducedNovo-Difenac-K (diclofenac potassium) 50 mg enteric coated tablets, a nonsteroidal anti-inflammatory agent.
Retavase (reteplase, recombinant) injection is a new thrombolytic agent from Crystaal Corporation. The product is indicated for use in the management of acute myocardial infarction (AMI) in adults. It is used to lyse thrombi which obstruct the coronary arteries, improve ventricular function and reduce the incidence of congestive heart failure following AMI, and to reduce mortality associated with AMI.
NEW DOSAGE FORMS/
Hoffmann-La Roche is now supplying CellCept (mycophenolate mofetil) 500 mg tablets, in addition to the original 250 mg capsule. One 500 mg tablet is bioequivalent to two 250 mg capsules. CellCept is indicated for the prophylaxis of organ rejection in patients receiving allogenic renal or cardiac transplants.
Lamisil Topical Spray (terbinafine HCl 1%) is now available from Novartis. The new dosage form joins Lamisil 125 mg and 250 mg tablets, and 1% cream. Lamisil spray should be applied once daily for one week, for the treatment of fungal infections of the skin (tinea pedis, tinea corporis/cruris). It is used twice daily for one week, for the treatment of pityriasis (tinea) versicolor. The spray is not effective for fungal nail infections.
Hoffmann-La Roche’s Activasert-PA (alteplase) intravenous injection is now approved for the management of acute ischemic stroke in adults. Its use is intended to improve neurological recovery and reduce the incidence of disability from stroke. Treatment should only be initiated within three hours of the onset of stroke symptoms, and after exclusion of intracranial hemorrhage by cranial computerized tomography (CT) scan or other diagnostic imaging method sensitive enough to detect intracranial bleeding.
Parke-Davis has expanded the indications of the lipid-lowering agent, Lipitor (atorvastatin calcium), to include the management of dysbetalipoproteinemia (Type III), hypertriglyceridemia (Type IV) and homozygous familial hypercholesterolemia.
Leo Pharma has added a patient information section to the product monograph for the antibiotic, Pondocillin (pivampicillin).
Hoffmann-La Roche has revised the product monograph for Rocaltrol (calcitriol). Mothers taking the drug are now permitted to breastfeed, provided that the serum calcium levels of the infant and mother are monitored. (See also below for a new dosing regimen for Rocaltrol.)
Janssen-Ortho has added a patient information section to the Risperdal (risperidone) product monograph. The directions for opening the oral solution bottle and using the pipette have also been slightly modified. In addition, the description of the 1 mg tablet as “half-scored” has been changed to “may be scored” in anticipation of the introduction of non-scored tablets later this year.
Glaxo Wellcome has made extensive revisions to the Purinethol (mercaptopurine) product monograph. The dosage and administration section now includes dosing guidelines according to body surface area as well as body weight. The monograph indicates that there are no specific studies of the drug in elderly subjects, but if there is any evidence of hepatic or renal impairment in this age group, a reduction in mercaptopurine dosage should be considered.
Glaxo Wellcome has discontinued Quinidine sulphate 200 mg tablets due to low demand.
The anabolic steroid, Anapolon (oxymetholone), is no longer available from the U.S. supplier, Unimed Pharmaceuticals. As a result, the Canadian distributor, Hoffmann-La Roche, has discontinued the product in Canada. Anapolon was indicated for the treatment of anemias (e.g., aplastic anemia) caused by deficient red blood cell production. Bone marrow transplantation or immunosuppressive therapy are first-line therapies for aplastic anemia; anabolic steroids have been effective in some refractory cases. With the discontinuation of Anapolon, other anabolic steroids which could be considered for use in aplastic anemia include danazol and nandrolone decanoate.
NEW DOSING REGIMENS
Dosing guidelines for pediatric patients have been approved for Abbott’s HIV protease inhibitor, Norvir (ritonavir). As in adults, the drug should be used in combination with other antiretroviral agents. The pediatric starting dosage of ritonavir is 250 mg/m2 orally twice daily, increasing at two- to three-day intervals by increments of 50 mg/m2 twice daily until the recommended dosage of 400 mg/m2 twice daily (maximum 600 mg twice daily) is reached.
Hoffmann-La Roche has added a statement concerning the use of oral intermittent (pulse) therapy to the Rocaltrol (calcitriol) monograph. Dosing two or three times per week has been shown to be effective, even in patients refractory to continuous therapy. (See Monograph revisions above for additional changes to the Rocaltrol monograph.)
LU-ANN MURDOCH, B.Sc.Phm., is consulting clinical editor of Pharmacy Practice, consultant pharmacist for Patient Care, and on the editorial staff of The Pharmacist’s Letter.