H. pylori Infection May Aggravate GI Injury in Patients Taking Low-dose Aspirin
Doctors commonly prescribe low-dose aspirin for the prevention of heart disease, but it may also be responsible for some potentially serious side effects when taken frequently. Among the most common of these are gastrointestinal erosions and ulcers.
A recent study in The American Journal of Gastroenterology sought to determine whether certain people taking low-dose aspirin specifically, people infected with Helicobacter pylori, a common bacterium that can cause ulcers are more susceptible to gastrointestinal erosions and ulcers than people who are not infected with H. pylori.
Researchers from the University of Texas Southwestern Medical School and Baylor College of Medicine recruited 61 healthy volunteers between the ages of 18 and 61. Of these, 29 volunteers were infected with H. pylori. Forty-six of the volunteers were then randomly selected to receive low-dose aspirin (either 81 mg daily or 325 mg every three days), while 15 received a placebo.
After 46 days of treatment, an upper GI endoscopy was performed on each subject to determine the extent of gastrointestinal injury. The researchers did not detect any injury in the stomach or duodenum (upper intestine) of the patients taking placebo. In the subjects taking aspirin, those patients who were infected with H. pylori were significantly more likely to have gastrointestinal injury than those who were not infected (50% vs. 16%).
However, there was no difference between the groups in complaints of pain, nausea, vomiting, indigestion, or heartburn. In addition, the difference in outcomes between patients taking 81 mg of aspirin daily and 325 mg every three days was not statistically significant.
The researchers caution that the results of this study may not hold for older people or those with gastrointestinal diseases such as peptic ulcer disease, because the volunteers were healthy and aged 61 or younger. However, this study does suggest eradicating H. pylori infection may help prevent gastrointestinal erosions and ulcers in patients taking low-dose aspirin on a long-term basis.
October 2001 Update
FDA Approves Gleevec to Treat Leukemia
Chronic myelogenous leukemia (CML), one of four main types of leukemia, strikes about 5,000 people every year. On average, patients live 3-4 years after receiving a diagnosis of CML. Last week, the FDA approved Gleevec (imatinib mesylate, also known as STI 571) as an oral treatment for CML.
Gleevec has been shown to substantially reduce the level of cancerous cells in the bone marrow and blood of treated patients. In clinical trials, 90 percent of patients in the first phase of CML went into remission within the first six months of taking Gleevec. Of patients in the second phase of CML, 63 percent went into remission with Gleevec. The drug produced few side effects.
Additional studies need to be done to determine how long the effects of this drug last, whether patients become resistant to the drug, and, most importantly, whether Gleevec can actually extend a patient's life.
Still, the results are promising. Currently, the only cure for CML is a bone marrow transplant. Even if a patient is lucky enough to find a marrow donor match, the procedure is successful less than 2/3 of the time. Interferon, a widely used treatment for CML, can extend a patient's life for up to two years, but it has several serious side effects and does not cure the disease. Gleevec may be used in patients in the early stage of CML who do not respond to interferon therapy, and in patients in the later stages of CML.
Most people with CML have a chromosomal abnormality, known as the Philadelphia chromosome, in which portions of two different chromosomes are switched. The result is the creation of an abnormal protein that allows the uncontrolled production of white blood cells, which can interfere with the function of other organs in the body. Gleevec blocks a signal sent out by the abnormal protein, thus blocking the rapid growth of white blood cells.
The FDA's approval of the drug came after a surprisingly short 2½ months. Most drugs that, like Gleevec, are granted a priority review, take six months to approve. The approval was based on three separate studies that involved about 1,000 patients with CML. The drug has generated enthusiasm in the medical community because it targets a specific, cancer-causing protein, without damaging other cells.
Scientists at an American Society of Clinical Oncology meeting announced earlier this month that Gleevec had also produced remission in 180 patients with advanced cases of an intestinal cancer known as gastrointestinal stromal tumor (GIST). Until now, GIST cancers have been incurable; GIST patients normally die within one year of receiving their diagnosis.
May 2001 Update
Comparing the Side Effects of Prostatectomy vs. Radiation Therapy
Prostate cancer is the most commonly diagnosed non-skin cancer among men in the United States. When caught early, it is also among the most treatable. Two of the more aggressive and common methods of treatment for early-stage prostate cancer are radiation therapy and surgery (radical prostatectomy) to remove the prostate gland. Although both options have favorable outcomes, physicians have not reached a consensus on which therapy is more effective. This means that men who are treated with either surgery or radiation can usually expect to live for many more years. The caveat is that they often have to live with the side effects of their treatment. Deciding on a treatment option, then, becomes a question of which side effects are more likely with each therapy, and also which side effects are more tolerable to a particular patient.
A recent analysis of data from the Prostate Cancer Outcomes Study helps to clarify this issue by comparing the side effects of the two therapies in men between the ages of 55 and 74, two years after treatment. The results showed that men in both treatment groups experienced significant decreases in sexual function. Of the men in the surgery group, 80% became impotent, compared to 62% of the men in the radiation group. Age and status of sexual function prior to treatment affected these outcomes. Twelve percent of the men who underwent surgery experienced dripping or leaking urine, compared to only 2% of the men who had radiation therapy. Few men in either group were bothered by bowel problems. Of the men who were affected, however, radiation patients experienced more diarrhea, bowel urgency, and painful hemorrhoids (33%, 30%, and 19%, respectively) compared to surgery patients (22%, 16%, and 10%).
Overall, this study showed that men who opt for surgery can expect to have more urinary and sexual problems, while men who choose radiation are more likely to suffer from bowel disturbances. A man's age and initial health are also important factors in the development and duration of long-term side effects from either treatment. Physicians and their patients should use this information, as well as a discussion of the patient's priorities, preferences, and concerns, to help decide which treatment method is appropriate.
March 2001 Update
Children and Peanut Allergies
Children usually outgrow allergies to milk and eggs, but not to peanuts. In a recent study, researchers found that the majority of children with peanut allergies will have adverse reactions to accidental peanut exposure within five years. In addition, allergic reactions are likely to worsen over the years.
Researchers followed 83 children who were diagnosed with a peanut allergy before their 4th birthday. Of these children, 61 had initial non-life-threatening reactions, while 22 had potentially life-threatening reactions. After 5.9 years, they found that 50 of the 83 children had experienced a total of 115 adverse reactions to peanuts.
Most of the reactions increased in severity after the initial reaction. Of the children with initial non-life-threatening reactions who had additional reactions, 44% had at least one potentially life-threatening subsequent reaction. And of the 22 children who had initial life-threatening reactions followed by additional reactions, 71% had at least one additional life-threatening reaction.
In 12 of the original 83 children, the initial reaction occurred after touching, (not eating) peanuts, and they experienced only skin symptoms. Eight of these 12 had subsequent reactions, and all eight had at least one occurrence of respiratory or gastrointestinal symptoms. Children with only skin symptoms had significantly lower serum peanut-specific antibodies than those with other initial symptoms, but there was no "safe" antibody level below which subsequent reactions were only skin-specific.
Most children with peanut allergies accidentally ingest peanuts and this study showed that allergic reactions are likely to get progressively worse with each exposure. Children must be educated to avoid peanuts and foods containing peanuts. In addition, children should always have access to a self-injectable epinephrine kit that both parents and children should know how to use if the need arises.
February 2001 Update
Pet Reptiles and Salmonella
Between 1996 and 1998, approximately 16 state health departments reported salmonella infections in persons who had direct or indirect contact with reptiles (i.e., lizards, snakes, or turtles) to the Centers for Disease Control and Prevention.
Salmonella infection can result in severe illness and even death, particularly in infants, young children, and anyone with a compromised immune system. The CDC issued the following recommendations to reduce the chances of anyone in your family contracting this potentially deadly infection from these increasingly popular exotic pets:
- Pet store owners, veterinarians, and pediatricians should provide information to owners and potential purchasers of reptiles about the risk of acquiring salmonellosis from reptiles.
- People should always wash their hands thoroughly with soap and water after handling reptiles or reptile cages.
- People at increased risk for infection or serious complications of salmonellosis (e.g., children younger than age 5 and immunocompromised persons) should avoid contact with reptiles.
- Pet reptiles should be kept out of households where children younger than age 5 and immunocompromised persons live. Families expecting a new child should remove the pet reptile from the home before the infant arrives.
- Pet reptiles should not be kept in childcare centers.
- Pet reptiles should not be allowed to roam freely throughout the home or living area.
- Pet reptiles should be kept out of kitchens and other food-preparation areas to prevent contamination.
- Kitchen sinks should not be used to bathe reptiles or to wash their dishes, cages, or aquariums. If bathtubs are used for these purposes, they should be cleaned thoroughly and disinfected with bleach.