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Update From the Medical Journals: October 2009
October 30, 2009  By Mary Pickett, M.D.
Harvard Medical School What's the latest news in the medical journals this month? Find out what your doctor is reading. H1N1 Flu Is Here In the last month, there has been a surge in the number of new cases of H1N1 influenza, also known as "swine flu." There are cases reported in almost every state in the U.S. The first doses of vaccine against H1N1 flu were also released. However, fewer doses than expected have come through so far. Most people with H1N1 flu have not had serious symptoms. But many people have had complications and have been hospitalized. The most common complications of this flu are pneumonia, severe bronchitis and dehydration. Researchers at the Centers for Disease Control and Prevention (CDC) reported October 8 in the New England Journal of Medicine that of 272 patients who were hospitalized with H1N1 influenza, almost all of them received the antibiotic olseltamivir (Tamiflu). Still, one out of four patients needed treatment in the intensive care unit (ICU) and 7% of people who were hospitalized died of the flu, despite the use of ventilators (artificial breathing machines). Based in part on this study, CDC experts have identified several risk factors that made these people more vulnerable to complications from this flu. They included having diabetes, asthma, or severe obesity before becoming ill with H1N1 flu. (People with a body mass index or "BMI" over 40 are at highest risk; people with BMI over 30 may also be at risk according to the CDC.) However, data from a larger study presented at a news conference several days after the October 8 report found that nearly half (46%) of 1,400 adults who were hospitalized had been previously healthy. Children seem particularly vulnerable to getting severely ill with H1N1 influenza. By mid-October, the CDC had recorded 86 deaths this year among children with H1N1 flu. The CDC continues to track the spread of flu and offer updates. Another report in The New England Journal of Medicine on October 8 concerned activity of H1N1 flu in Australia and New Zealand. The winter months and "flu season" there occur from June through August. Fifteen times the usual number of ICU beds were needed because of H1N1 cases. This study suggests that a large wave of H1N1 hospitalizations may come as we move into the peak months of our usual flu season — November through February. Vaccination rates could significantly affect how many people are affected. The best way to prevent H1N1 flu is to get vaccinated. But the supply of vaccine doses is still limited. The CDC says that five groups of people should have priority for receiving the H1N1 vaccine. You are in a priority group if you are: - Pregnant
- Living with or caring for infants younger than 6 months old
- Working as a healthcare provider or as emergency medical services personnel
- Ages 6 months through 24 years old, whether or not you have a medical illness
- Ages 25 years through 64 years old, if you have a chronic medical condition that would put you at risk for complications, or if you are severely obese.
According to the CDC, you have an increased risk for complications if you have: - Asthma or lung disease
- Heart disease (with the exception of hypertension), kidney or liver disease
- Neurologic (brain) disease or neuromuscular disease
- Hematologic (blood) diseases (this would include leukemia and other related illnesses)
- Diabetes
- Conditions (or medications) that result in a weakened immune system
- Obesity
The CDC recommends offering the vaccine to lower risk people as long as the supply of vaccine is not limited. Lower priority groups for the vaccine include: - Ages 25 to 64, without a medical illness or obesity
- People over age 65
These recommendations are significantly different from the vaccination recommendations for the "seasonal" (non-H1N1) flu vaccination. Seasonal flu vaccination is recommended for children ages 6 months to 19 years, pregnant women, people 50 years and older, individuals who live in a nursing home or long-term care facility, anyone with chronic medical conditions, caregivers and health care workers, and people who share a home with an infant younger than 6 months or a person who has a weakened immune system or other significant illness. The H1N1 vaccination comes in two forms — an injection (not a live vaccine) and a nose spray (a weakened, live virus vaccine). Children ages 9 years or younger need two doses of the vaccine for best results. The vaccine doses should be spaced apart by at least 21 days (ideally, 28 days apart). The H1N1 vaccine and the seasonal flu vaccine can be given together, unless both are being given as a nasal spray. People with chronic illnesses or severe obesity who develop flu symptoms (fever, cough, headache, sore throat, runny nose, and possibly vomiting or diarrhea) should contact their doctor quickly and consider starting the medication olseltamivir (Tamiflu). It is most effective if a person takes it within the first 48 hours of symptoms. Currently this medicine is not recommended for people who do not have underlying medical conditions, or who have mild enough symptoms of flu that they do not need to be hospitalized. Back to top More News in Brief - Two "Neuropathic" Pain Drugs May Be Better than One. To provide pain relief, doctors sometimes choose from a list of drugs that can reduce "neuropathic" (nerve) pain. These medicines can be used alone, or can be added to a pain treatment plan that includes another medicine, such as opiate pain medicine. Examples of neuropathic pain medicines include nortriptyline, amitriptyline (Elavil), gabapentin (Neurontin) or duloxetine (Cymbalta). Traditionally, only one neuropathic pain medicine is used at a time. But a new study published in The Lancet online on September 29 examined the effect of combining two different neuropathic pain medicines. The study compared the benefit of nortriptyline alone, gabapentin alone or nortriptyline plus gabapentin. The 47 patients in the study reported pain scores from 0 to 10 and also reported side effects. Without treatment, the average pain score was 5.4. The best pain relief came with use of both medicines, with an average score of 2.3. There did not appear to be more side effects with combination drug treatment. The strategy of combining neuropathic pain medicines is not widely used, but it might provide additional relief for some patients.
- Acetaminophen (Tylenol) Might Blunt the Benefit of Childhood Vaccines. Parents and pediatricians often give children acetaminophen (Tylenol) prior to or immediately after vaccinations. This helps reduce pain from the shots and helps prevent fever. A study published by The Lancet on October 15 indicates that use of acetaminophen on childhood vaccination days could weaken the effect of vaccinations. The study randomized more than 450 children from the Czech Republic into two groups. One group received traditional childhood vaccinations without being treated with a form of acetaminophen called paracetamol. The other group received doses of paracetamol during the day of the vaccinations. Fewer children in the treated group had fever. However, when researchers measured specific immune system proteins after the vaccines were administered, the children also had a less active immune response.
- Link to New Virus May Explain Chronic Fatigue Syndrome. A new discovery might help solve a mystery: the cause of chronic fatigue syndrome (CFS), also known as chronic fatigue and immunodeficiency syndrome (CFIDS). Researchers published their findings October 8 in the journal Science. A recently discovered virus named XMRV is detectable in the blood of 67% of people who have been diagnosed with CFIDS but is present in only 3% of healthy people. Because it embeds itself in an infected person's DNA (genetic code), XMRV is called a "retrovirus." A retrovirus can cause a prolonged infection. XMRV does appear to cause a mildly weakened immune system. Although it has not been proven that this virus is a cause of chronic fatigue syndrome, the possibility is an exciting one to explore. Understanding the cause of this illness could lead to helpful treatments.
- Experimental Vaccine Might Aid in Fighting Cocaine Addiction. A vaccine designed to cause a person's immune system to produce antibodies against cocaine molecules may help fight cocaine addiction. The study appeared in the Archives of General Psychiatry. The antibodies don't destroy the cocaine. Instead, they attach to cocaine molecules and prevent cocaine from crossing the blood-brain barrier into the brain. The study enrolled 115 people who sought help for addiction to cocaine. Each person received five doses of the experimental vaccine. Thirty-eight percent of the treated people had what researchers considered to be a robust immune reaction from the vaccine — enough to prevent cocaine from causing a euphoria or "high." If cocaine was found in fewer than half of the urine drug test samples that were collected in the early weeks after the vaccination program, the vaccine was considered a success. Fifty-three percent of this subset of people were able to reduce cocaine use to this level of frequency during the six months of the study. This compared with only 23% of people who had a weak response to the vaccine (fewer antibodies). Clearly, even with this experimental vaccine and with the motivation to quit, cocaine addiction is difficult to get away from. This is probably not a big enough benefit to justify widespread use of the vaccine, since we don't know the long-term safety of this vaccine. But it might be enough of a response to justify continued research work with this new strategy.
Back to top Mary Pickett, M.D. is an Associate professor at Oregon Health & Science University where she is a primary care doctor for adults. She supervises and educates residents in the field of Internal Medicine, for outpatient and hospital care. She is a Lecturer for Harvard Medical School and a Senior Medical Editor for Harvard Health Publications.
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