Megace and Thromboembolic Disease
Source: Koller E, et al. Nutrition 1999; 15:294-298.
Megestrol acetate (megace) is used extensively in the treatment of wasting in patients with AIDS and malignancy. Because it is a progestational agent, there is concern that it may affect clotting pathways, resulting in increased coagulability and thromboembolic risk in some patients. Koller and colleagues from the Center for Drug Evaluation at the FDA investigated the occurrence of 92 episodes of thromboembolism in 90 patients receiving megestrol acetate who were reported to the FDA between 1970 and 1997. Events included pulmonary emboli (n = 45), deep venous thrombosis (n = 38), central retinal vein occlusion (n = 3), and, in one patient each, superficial venous thrombosis, axillary vein occlusion, superior vena caval occlusion, brachiocephalic artery thrombosis, and internal jugular and subclavianvein occlusion. Events generally occurred within the first three months of drug use.
Only 11 of the 90 had AIDS (12.2%). There was no apparent difference in the daily dose between AIDS and nonAIDS patients. However, the average dose of megestrol acetate was significantly lower in patients with pulmonary emboli (mean, 490 mg/d) compared with those with deep venous thrombosis (mean, 1554 mg/d). No other risk factor could be identified in this retrospective survey, although Koller et al acknowledged the difficulties in the collection of key information years after an event. In addition, underlying conditions that may have predisposed patients to thrombosis, such as protein C deficiency, could not be assessed.
Fewer patients with AIDS and thromboembolic events were reported than those with malignancy, possibly because many patients with AIDS are younger, male, and have less underlying disease, and are, therefore, less predisposed to thromboembolic disease. While clinicians should be aware of the remote possibility of thromboembolism in their patients with AIDS, Megace remains a safe and effective agent for use in those with wasting. n
Household Exposure to Hepatitis A Warrants Vaccination
Source:Sagliocca L, et al. Lancet 1999; 353:1136-1139.
Sagliocca and colleagues from Naples, Italy, investigated the protective efficacy of hepatitis A vaccine in household contacts of patients with sporadic hepatitis A infection. Households were randomly assigned to receive either hepatitis A vaccine or no vaccine. Based on earlier clinical trial data demonstrating that 96% of adults receiving 1440 ELISA units of hepatitis A vaccine developed protective titers within four weeks of inoculation, the selected dosages used in this study were 1440 ELISA units for adults and 720 ELISA units for children. All vaccine recipients were vaccinated within eight days of onset of symptoms in the index case. Serologies were obtained at baseline, 14, and 45 days.
About one-third of the participants were immune at baseline, and an additional nine patients had evidence of positive IgM antibody and were classified as "co-infected." No household contact developed symptoms of acute hepatitis A infection within two weeks of onset of symptoms in the index case.
A statistically significant benefit to hepatitis A vaccination in household contacts resulted in premature study closure. Secondary infections occurred in only two of 71 (2.8%) households in the vaccine group compared with 10 of 75 households (13.3%) in the nonvaccine group. Among household contacts, two of 197 (1.0%) of those receiving vaccine vs. 12 of 207 (5.8%) of those in the nonvaccine group developed secondary infection. The protective efficacy of vaccine was 82%. Sagliocca et al estimated that vaccination was required in 18 individuals to prevent secondary infection in one—at a cost of about $900 in the United States. Although the study was uncontrolled, similar beneficial results were obtained in a recent effort to halt an outbreak of hepatitis A infection in Native Americans in Alaska. Clinicians should recognize this as an opportunity to quickly administer hepatitis A vaccine to household contacts of patients with known or suspected hepatitis A infection. n
Pinworms and Urinary Tract Infections
Source: Ok UZ, et al. APMIS 1999; 107:474-476.
Ok and colleagues explored the possible relationship between Enterobius vermicularis (pinworms) and urinary tract infection (UTI) in young girls in Turkey. Using the standard cellophane method, pinworms eggs were found in 20 of 55 (36.4%) young girls with UTI. In contrast, only nine of 55 (16.4%) young girls who had never had a UTI had evidence of pinworms (P < 0.05). Ok et al suggest that pinworms may be a risk factor for UTI in little girls and advise close examination with nighttime application of cellulose tape to both the perianal and peroneal areas in any young girl with a UTI.
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