Digoxin & Gender

Digoxin is a very commonly prescribed drug, and is used to improve the function of chronically failing hearts, and for controlling the heart rate in the case of certain cardiac rhythm disturbances.  In patients with congestive heart failure (CHF), digoxin improves the strength of heart muscle contractions.  Digoxin is derived from the leaves of the foxglove plant (Digitalis purpurea), and has been prescribed in one form or another since the 18^th century. 

A newly published study in the New England Journal of Medicine calls into question the effectiveness of this venerable heart medication.  The so-called “Digitalis Investigation Group” study looked at 6,800 patients with CHF.  Among men with CHF, the use of digoxin appeared to have no effect on overall death rates when compared with men who were given a placebo (“sugar pill”).  Interestingly, women who took digoxin experienced a 23 percent increase in the overall rate of death when compared to women taking placebo pills. 

Although this study found a slight reduction in the number of hospital visits associated with the use of digoxin by CHF patients, the lack of improvement in the overall death rate for men taking the drug is disappointing news.  At the same time, the increased risk of death associated with digoxin use in women with CHF is worrisome.  This is the first study to show such a gender-specific difference in the effects of digoxin, although the reasons for this observation are unclear at this time.  This study would appear to generally call into question the benefits of digoxin in the treatment of CHF, particularly among women.  However, if you are currently taking digoxin for a heart condition, please do not arbitrarily stop taking this medication.   I would recommend, instead, that you visit with your doctor, and discuss this study and its implications.  Additional studies will have to be done to confirm this study’s novel findings.  Meanwhile, digoxin may have already lost some of its therapeutic luster.

Driving & Degenerative Disc Disease

Chronic low back pain is extremely common in industrialized nations, and is the most common cause for workman’s compensation claims.  Professional drivers, such as truck and taxi drivers, have long been thought to be at increased risk for developing lumbar disc degeneration.  The intervertebral discs are tough fibrous rings that serve as shock absorbers for the spine.  It has been assumed that prolonged sitting, and vibration transmitted to the spine’s natural shock absorbers, play a key role in this increased risk of spinal disc disease among drivers.  However, a new study in the journal Lancet appears to suggest otherwise.

In an interesting study, 45 pairs of identical male twins were studied in Finland.  The twin pairs were especially selected in that one of the two twins in each pair was a driver by occupation while the other twin was not.  Driving histories were obtained for all study participants, and spinal disc degeneration was assessed by MRI scans.  The study failed to identify any difference in the incidence of spinal disc degeneration between the brothers who were professional drivers and their non-driver twins.  The study’s authors conclude that prolonged driving can exacerbate preexisting back conditions, but does not appear to cause or contribute to degenerative changes in the spinal discs.

Coenzyme Q₁₀ & Parkinson’s Disease

Parkinson’s disease (PD) is an incurable neurological disorder that results from the deterioration and death of dopamine-producing cells in a part of the brain called the substantia nigra.  Patients with PD develop progressive difficulties in initiating movements.  PD also causes tremors of the hands and, in some cases, dementia similar to that which occurs in patients with Alzheimer’s disease.  Some of the lost dopamine can be replaced or scavenged in the brains of patients with PD with drugs.  More recently, transplantation of substantia nigra cells from fetal brain tissue has been attempted with variable degrees of success (and considerable ethical controversy).  

In the current issue of the Archives of Neurology, the effects of coenzyme Q₁₀ on early PD were studied in 80 patients over a period of 16 months.  Coenzyme Q₁₀ is a naturally occurring substance in the body that plays a critical role in energy metabolism, and also has antioxidant properties as well.  In this study, coenzyme Q₁₀, when given in higher doses (up to 1,200 mg per day), significantly slowed the progression of PD-related movement disorders.  This is an intriguing study, and it is consistent with other studies that have shown beneficial effects in patients with early PD who were taking high doses of antioxidants, including vitamins C and E.  High doses of antioxidant compounds appear to slow the loss of substantia nigra cells in PD patients who are in the early stages of this disease.  Further study of this phenomenon and the effects of coenzyme Q₁₀ in particular, should be studied on a larger scale, as this pilot study only looked at 80 patients.  However, this small study may offer some hope to the approximately one million Americans who suffer from the devastating effects of PD.

Ginseng & Erections

Ginseng has been used in many Asian countries for centuries to cure a variety of ills, including impotence.  However, previous scientific studies have not been able to demonstrate any specific therapeutic effects associated with ginseng consumption.  A study reported in the current issue of the Journal of Urology might change this perception of ginseng, however.

A total of 45 male patients with documented erectile dysfunction were enrolled in the study.  Half of the patients took ginseng tablets for 8 weeks (900 mg, three times per day), and the other half took a placebo pill for 8 weeks.  All patients were then observed for 2 weeks without receiving either ginseng or placebo pills.  After this 2 week hiatus, the patients switched treatments, with the prior ginseng group subsequently receiving placebo pills for 8 weeks.  The prior placebo pill group was also switched to ginseng for a period of 8 weeks after the 2 week rest period.  Using blood hormone levels, patient surveys, a device that measures penile tip rigidity, and ultrasound evaluations of the penis, the study’s authors concluded that the use of ginseng significantly increased penis erectile function and rigidity.  In view of the many unsubstantiated health claims that have been made for ginseng over the years, and the lack of sound scientific evidence to support such claims, this study is highly interesting.  Additional studies, involving larger numbers of patients, should be performed to confirm the findings of this small pilot study.  However, ginseng could prove to be a useful treatment for erectile dysfunction, either with or without Viagra.  It should also be noted that a number of new erectile dysfunction drugs are about to hit the market.  Most of them are chemically similar to Viagra, but have been designed so as to enhance their effectiveness while reducing the side effects associated with Viagra.

Viagra & Stroke

While I am on the subject of Viagra, an interesting little study in the journal Stroke looked at the effects of Viagra on rats that suffered strokes following surgical blockage of the main artery feeding their brains.  Scientists surgically blocked the rats’ cerebral arteries and then administered Viagra to some of the rats for a duration of 7 days, while the remaining rats received only water.  Surprisingly, the rats that were supplied with Viagra in their drinking water made a significantly better neurological recovery, following their strokes when compared to the rats that received water only.  While there was no difference in the size of the stroke between the two groups of rats, a study of their brains revealed an increase in the number of nerve cells in several regions of the brain among the rats that had received Viagra.  This fascinating study suggests a possible role for Viagra in the treatment of acute strokes.  Additional preliminary studies will, of course, have to be performed in human patients who have recently developed a stroke.  If Viagra proves to have similar beneficial effects on humans as it appeared to have on rats, then this could be a very exciting breakthrough in the care of patients with strokes.

Dr. Robert A. Wascher