Rx Update: September 2003
Joan Murhammer, R.Ph., Mary Ross, R.Ph., M.B.A., Kevin Bebout,
R.Ph.
Peer Review Status: Internally Reviewed
Estrogen and Estrogen and Progestin Combination Products
The prescribing information for all estrogen (e.g.,
Premarin®) and estrogen and progestin combination (e.g.,
Prempro®) therapies has been updated to include a boxed warning
with new risk information from the Women's Health Initiative (WHI)
study. The study reported increased risks of myocardial infarction,
stroke, invasive breast cancer, pulmonary emboli, and deep vein
thrombosis in postmenopausal women during 5 years of treatment with
conjugated estrogens 0.625 mg combined with medroxyprogesterone 2.5
mg when compared to placebo. Because of these risks, it is
recommended that estrogens with or without progestins should not be
used for the prevention of cardiovascular disease and should only be
prescribed at the lowest effective dose and for the shortest
duration.
Zonisamide and Topiramate
Zonisamide (Zonegran®) and topiramate (Topamax®) are both
anticonvulsants that have been reported to increase the risk of
developing oligohidrosis (decreased sweating) and hyperthermia.
Oligohidrosis and hyperthermia may have potentially serious sequelae,
which may be prevented by prompt recognition of symptoms and
appropriate treatment. Patients treated with these agents should be
monitored closely for evidence of decreased sweating and increased
body temperature, especially in warm or hot weather.
Salmeterol and Salmeterol and Fluticasone Combination
Products
The FDA announced the addition of new safety information and
warnings to the labeling for drug products that contain salmeterol
(e.g., Serevent®, Advair®), a long-acting bronchodilator used
to treat asthma and chronic obstructive pulmonary disease. The new
labeling includes a boxed warning about a small, but significant,
increased risk of life-threatening asthma episodes or asthma-related
deaths observed in patients taking salmeterol in a recently completed
large safety study.
Alfa Interferons
A boxed warning has been added to all alfa interferons regarding
the occurrence of neuropsychiatric, autoimmune, ischemic, and
infectious disorders in patients taking these medications. These
warnings apply to interferon alfa-2a (Roferon-A®), interferon
alfa-2b (Intron-A®), peginterferon alfa-2a (Pegasys®),
peginterferon alfa-2b (Peg-Intron®), and interferon alfacon-1
(Infergen®). Alfa interferons should be withdrawn in patients
with worsening signs or symptoms of these conditions. These
interferons should also be used with extreme caution in patients with
a history of psychiatric disorders. Patients should be advised to
immediately report any symptoms of depression and/ or suicidal
ideation to their prescribing physicians. Physicians should monitor
all patients for evidence of depression and other psychiatric
symptoms. In severe cases, the interferon should be stopped
immediately and psychiatric intervention instituted.
Lindane
The FDA has issued a Public Health Advisory concerning the use of
lindane (Kwell®) for the treatment of scabies and lice. The new
warning emphasizes that because of the potential for serious
neurological adverse effects, lindane should only be used as a
second-line treatment. The Advisory also updates information about
its potential risks, especially in children and adults weighing less
than 110 pounds, and reminds practitioners that reapplication of
lindane is not appropriate if itching continues after a single
treatment. To minimize the potential for patients to apply an excess
amount and to minimize reapplication of lindane, package sizes will
be limited to 30 to 60 ml. Pharmacists should dispense a quantity
sufficient for a single treatment, not to exceed 60 ml. A Medication
Guide, designed to inform patients of the risks of lindane products
and provide instructions for appropriate use of the drugs, must now
be dispensed by the pharmacist with each new prescription. Lindane is
not stocked at UIHC.