Monday, September 29, 2008

Beta blockers and post-traumatic stress disorder

One of my family members watched another person die suddenly, violently, and unexpectedly this weekend. I think I'm more freaked than my near and dear one is, but here's my doctorly thought processes after I was done flipping out.

Norepinephrine (NE, aka noradrenaline) is a neurotransmitter integral to the stress response and the formation of emotional memories. The beta-sympathetic nervous system (the automatic 'fight or flight' response that occurs without conscious activation) is mediated by NE which enhances the vivid but not necessarily accurate memories associated with highly emotional experiences. Think of a moment that was a charged one for you, say where you were when President Kennedy was shot (if you're old enough) or when you first heard about the World Trade Centers, and notice the details of that memory compared with other, blander recollections.

Experts call the development of post-traumatic stress disorder (PTSD) a 'derailment of memory process.' Not everyone is prone to an exaggerated or detrimental response to strongly charged experiences, but those who are can develop stubborn and destructive behavior patterns that ripple way beyond the actual trauma over time. While bioethicists argue over the morality of supressing intense and unpleasant memories, for better or worse it is possible to attenuate these memories through the use of beta-blockers. Amazingly, not only do the benefits of such therapy accrue when the medication is used shortly after the traumatic even, but also when the event is re-enacted through scripted imagery after some time has passed.

Should I offer beta-blockers (such as propranolol or metoprolol) to my family member? Perhaps I should just take a deep breath and take some myself.

Saturday, September 20, 2008

The amygdala and the social conservative

I've mentioned before that I have an overactive amygdala. Through a series of genetically determined events that I've explained before here, I get an intense second-hand fear response that renders me unable to watch scary movies. Just can't take it when the actress hears a noise and heads right down to the cellar to investigate when I know full well she should run even as I also know it's only a movie.

Now anxiety is a good thing when it sets off an appropriate 'fight or flight' response that allows us to recognize danger and either run or creep down those stairs provided we're fully certified in the martial arts (of course, karate is no use at all against the supernatural...). And it's a bad thing when it renders us unable to leave the house or apply for a job (met a patient like that just yesterday). But who'd have thought that an overactive--or indifferent--amygdala might affect our political beliefs? Well, color me conservative as I read the following from Science Magazine.(1)

Political scientists teamed up with psychologists in Texas and Nebraska to find out if our political beliefs might have a biological basis. In their own words:

In a group of 46 adult participants with strong political beliefs, individuals with measurably lower physical sensitivities to sudden noises and threatening visual images were more likely to support foreign aid, liberal immigration policies, pacifism, and gun control, whereas individuals displaying measurably higher physiological reactions to those same stimuli were more likely to favor defense spending, capital punishment, patriotism, and the Iraq War.

During session one, the scientists quizzed the group--preselected for the strength of their political convictions no matter what the content of their attitudes-- on their political beliefs, demographics, and personality traits. When the subjects next came down to the lab, they were hooked up to physiological equipment that measured change in skin conductance as well as the strength of their blink or startle response. They were then shown three threatening images (a very large spider on the face of a frightened person, a dazed individual with a bloody face, and an open wound with maggots in it) or three sweet little pictures (a bunny, a bowl of fruit, and a happy child) interspersed amongst non-charged visuals.

Arousal causes increased moisture on the skin which increases conductance and fear causes a hard flinch or blink response of the muscles around the eye. Well I don't think I'd have a problem with a maggot show, but I know my heart rate would rise and I'd shut my eyes in moment to a large spider crawling on someone's face. The investigators found that an exaggerated response to the threatening pictures did correlate with a more conservative or socially protective attitude.

While the researchers were reluctant to conclude just what cause and effect processes were at work, they conjectured that "political attitudes and varying physiological responses to threat may both derive from neural activity patterns, perhaps those surrounding the amygdala. Amygdala activity is crucial in shaping responses to socially threatening images and may be connected to political predispositions."

Please note that in no way do I imply that all social conservatives have an exaggerated fear response. Nor do I think that close vigilance on the part of our society with respect to external danger is a bad thing.
Oxley, DR, et al. Political Attitudes Vary with Physiological Traits. Science19 September 2008: Vol. 321. no. 5896, pp. 1667 - 1670.

Friday, September 19, 2008

Viagra, women, and antidepressants

Depression is a surefire way to kill your libido. Treating depression with antidepressants is also a surefire way to kill your libido. Initially, patients may be so relieved to no longer be depressed that they are willing to give up their sexual interests for the medication benefits. After awhile, however, the increased pleasure in life and relationships makes intimacy issues unacceptable.

Doctors at the University of New Mexico wondered if phosphodiesterase type 5 inhibitors (aka Viagra, Cialis, or Levitra) might improve the sexual outlook for women whose spirits have risen on antidepressants even as their libidos have fallen. Viagra and company are known to lift certain parts in men on depression meds.

Over a period of 4 years, they randomized 98 women whose depressions AND sexual interests were completely squashed on serotonin reuptake inhibitor type medications. Taking no one's word for granted, they not only followed up the women's sexual activity event log, but also administered the Clinical Global Impression function scale, the Female Sexual Function Questionnaire, the University of New Mexico Sexual Function Inventory (female version of course), AND the Hamilton Depression Rating scale (just to make sure no depression was creeping back in the picture).

The women on the real deal Viagra sent their Clinical Global Impression sexual function scale soaring to nearly double the levels of their pre-treatment activity. They also improved their scores on their Sexual Function quizzes. The investigators do note that this study selected for a group of women motivated to improve their sexual functioning and relationships, and therefore the findings might not be generalizable to all women experiencing such troubles while on antidepressants. It's also possible that filling out forms and quizzes on sexual functioning might enhance sexual interest.

I find this study particularly interesting as Viagra-like drugs work particularly well in men through the promotion of blood flow into certain parts that must be engorged with blood for proper sexual functioning. It is encouraging to find that the medications can increase interest and activity in women whose sexual response is less dependent on the localized pooling of blood.

Sunday, September 14, 2008

Herd Immunity...

or why you should get a flu shot.

Flu season is coming, and hopefully this year's outbreaks will be preceded by a robust flu shot season. Here are the 2 most commonly cited reasons why my patients decline the vaccine:
  1. I always get the flu from the flu shot. While some people notice fluish sorts of symptoms such as mild fever and muscle aches after receiving the shot, the inactivated viral particles which comprise the vaccine cannot cause disease.
  2. I never get the flu. Well, lucky you. Remember, however, those who await your arrival back home. Perhaps you generally don't get the flu, but if you with your hardy immune system pick up a mild case while in close proximity with the coughing public, that young child, elderly grandma, or chronically ill spouse could be vulnerable to an amplified version of same with devastating or even fatal results.
Be a good member of the herd. When you get vaccinated, the influenza virus does not get a free ride in your respiratory tract on to its next victim.

Sunday, September 07, 2008

You can change your wicked ways...

but at the heart of your matter, your poor choices live on.

The Coronary Artery Risk Development in Young Adults (CARDIA) study followed twenty years of health outcomes in over 3500 young adults. The researchers studied modifiable risk factors such as cigarette use, prehypertension (BP's 120-139/80-89), LDL-cholesterol, and fasting blood sugars.

Many of the subjects with less than sterling health habits didn't smoke that much nor did they have huge elevations in the other parameters studied. Many of them turned their acts around and improved their lifestyle choices over the course of the trial. Despite improvements made, their early adult profiles were more predictive of the presence of coronary artery calcification (CAC) after age 35 than their most current situation. CAC has been shown to correlate with the presence of atherosclerotic changes in coronary arteries.

Monday, September 01, 2008

Voltaren Gel

This is a great idea, but the logistics are awkward.

Voltaren is an non-steroidal anti-inflammatory (NSAID) pain reliever, and a rather effective one at that. It is available in pill form as the generic diclofenac. The downside of any NSAID is its adverse effect on the stomach and intestinal tract, causing pain, gastritis, ulcers, and diarrhea. In addition, the drugs can increase the risk of stroke and heart attack, and, in susceptible individuals, can decrease blood flow to the kidneys thus increasing the risk over years of use of decreased kidney function. Specific to Voltaren is the risk of "severe hepatic reactions, including liver necrosis, jaundice, fulminant hepatitis with and without jaundice, and liver failure" per Well shoot, who wants any of that?

We do, however, want arthritis pain relief, and Voltaren does that well. So Novartis minced it up and put it in an alcohol-based gel so that we could smear it right on our throbbing joints. Once absorbed through the skin, it reduces arthritic hand pain 46% after 6 weeks of use, and pain levels plunge 51% after 3 months of slathering it on arthritic knees. Drug levels reaching your stomach, kidneys, and liver are 6% that of an oral dose so, while the risks are not nothing, they're a whole lot less than the pill delivers.

The problem is in the how much cream how often department. The web site recommends 2 gm four times daily to upper extremity sites and 4 gm four times daily for the lower extremity. A tube of toothpaste is 170 gms so that amount of Voltaren Gel would get you through just over ten days of knee treatment. The stuff is definitely gooey, lightly but pleasantly scented, and dries within 4-5 minutes leaving a light sheen but no residual sticky stuff. I cannot imagine using it during the workday if I wore pantyhose. Pulling them back up again after gelling your hip would be like getting a wet bathing suit back on a small child. But then again, who wears pantyhose anymore? What about for one throbbing , chronically hyperextended index finger swollen from years of writing chart notes and prescriptions? The very thing I think, but you can't wash the area for 1 hour after each application.

The other problem is cost. By my calculations, you would apply your way through $172 worth of gel to service one bum knee for a month. Does insurance pay? Dunno, but I kind of think not.