Parent Project Muscular Dystrophy - Leading the Duchenne muscular dystrophy community






Treatment / Care
Treatment / Care • Steroids/Nutritional Supplements/Antibiotics
Steroids/Nutritional Supplements/Antibiotics
There are multiple steroid/supplemental treatments for DMD although there is little agreement (even among researchers and clinicians) about many of them. Options include:


Prednisone
This is a catabolic steroid that slows the loss of muscle degeneration. It is the drug most widely used to treat DMD. In some cases walking may be prolonged for up to two years or more. Not only is muscle loss halted but its strength and function also improve dramatically. Unlike anabolic steroids taken by athletes and body builders, catabolic steroids do not build up tissue but instead break it down.

Why use these rather than anabolic steroids? Catabolic steroids, like the natural hydrocortisone, help the body break down tissues to release glucose (sugar) and mobilize energy in response to stress or danger. The exact way in which prednisone helps DMD patients is still not known, but it is likely due to its anti-inflammatory and immunosuppressant effects. Like hydrocortisone, prednisone fights inflammation (swelling) in injured or damaged tissues by suppressing the immune system. The cytotoxic T lymphocytes that rush in to clear away damaged cells may be slowed. Some researchers have speculate that prednisone may also somehow stimulate muscle protein production.

Because of this sugar effect, catabolic steroids are also known as 'glucocorticoids'. They are made and released from the outer portion (or cortex) of the adrenal gland, so they are also known as 'corticosteroids'. Prednisone is a synthetic form of the natural corticosteroid hydrocortisone. Prednisone has many pharmaceutical brand names.

Controlled tests with placebos clearly confirm that prednisone alleviates dystrophinopathic (characteristic produced by the absence of dystrophin) effects. Muscle mass and strength increases, though CK levels remain unaffected (as the muscle does not heal). Likewise, when young men who have been on prednisone stop taking it, they seem to lose its beneficial effects rather rapidly, no matter how long they have been on it. Prednisone works and works well, even though no one knows why.

However, for all its clear benefits, prednisone is known to have several strong side effects, including fluid retention (hence bloating and weight gain) which can lead to high blood pressure and the development of cataracts in the lenses of the eye. In some cases prednisone's benefits in strengthening muscle are cancelled out by obesity and inactivity. Linear growth (in height) may be arrested. There are also severe psychological side effects, such as difficulty concentrating, sleeping, and controlling emotions. Impairment in thinking, reading, and coping skills can lead to depression or aggression. Finally, long term use of immunosuppressants like prednisone can also impair the body's ability to fight infections and heal wounds.

Prednisone use must be monitored carefully to ensure that any gains in muscle function are not outweighed by negative side effects. Prednisone may have to be administered along with other oral supplements, such as calcium (to prevent osteoporosis). For many parents and physicians, the hardest decision is when to begin steroid use. Another major dispute involves the dosage regimen. A schedule in which the patient alternates periods of times on and off prednisone may help to provide the desired gains while blunting the harmful side effects. Currently there is no agreement from clinicians whether a "ten days on, ten days off" schedule, or an alternating "one day on, one day off" schedule, or even two high doses of prednisone a week (10 mg/kg/week) is best. In most cases prednisone is administered in daily doses of 0.75 mg/kg body mass/day. Still, different parents, physicians, and researchers will all give different answers. It may be that the proper dosage depends largely on the age and severity of the dystrophinopathic (characteristic produced by the absence of dystrophin) phenotype.

Deflazacort
Like prednisone, this is a catabolic steroid. It is not marketed in the U.S., though it is available in Canada, Mexico and other countries. As with prednisone, there is evidence that deflazacort significantly improves muscle strength and function. In addition, it appears to have less severe side effects than prednisone. However, although deflazacort may have fewer side effects (and it still has some) it is not otherwise more effective and is difficult for U.S. residents to obtain. In the past, U.S. residents have been able to obtain deflazacort (with a prescription only) through Victoria Pharmacy in Switzerland.

Albuterol
This is an immunosuppressant drug that is widely used in inhalant form for asthmatics. Preliminary evidence suggests that it may aid DMD young men by suppressing the immune cells that rush in to clean up and remove "leaky" muscle cells and debris. As with prednisone, albuterol interferes with the body's normal inflammation response. Though early data indicates few major side effects, all immunosuppresants are potentially harmful in that they may leave the patient unable to fight routine infections. Albuterol also appears to have some anabolic effects in that it promotes the growth of muscle tissue.


Creatine
This is a nutritional supplement that has recently gained much notice. Creatine helps the body to build up muscle's energy supply. The creatine kinase or CK enzyme (which is released from damaged muscle cells in DMD) adds chemical groups called 'phosphates' to creatine. Creatine stores these phosphate groups and donates them to contractile muscle filaments, which need them to contract. Creatine occurs naturally in muscle. Although it is found in meat and fish, it can also be added to the diet as a powdered nutritional supplement. The idea is that the more creatine muscle has, the more energy it has and thus the stronger its contraction. This is why professional athletes have experimented with extremely high doses.

Recent trials with DMD patients show a slight increase in muscle strength with administration of low levels (5 g/day) of creatine monohydrate. These low levels may prevent the potential kidney damage that can occur with high doses of creatine, but it is still difficult to give young DMD young men sufficient water along with creatine (and other dietary supplements). Behavioral changes may be another side effect of creatine use. As with prednisone (and other drugs listed here), preparing a plan in which the drugs are given for a short time followed by a break of one or several weeks may provide the same benefits as constant use. Medical studies of creatine and DMD continue.

Anabolic steroids
These, which act to build tissues in the body (unlike prednisone and other catabolic steroids that break them down), may help to fight DMD by compensating for muscle loss. A pilot study of oxandrolone, a synthetic anabolic steroid, showed some promise in preserving muscle strength. Anabolic steroids have attracted much attention from body builders and athletes who wish to "bulk up" their muscle mass, and the numerous harmful side effects of their use (including liver and kidney damage, sterility, stunting of growth, severe mood swings, and possible incidence of certain cancers) are well known and widely publicized. However, while research is still ongoing, the levels used by DMD young men-unlike those used by bodybuilders-would be rather low. Still, the levels of improvement (both in athletes as well as in DMD young men) appear minimal. It may be that a combination of anabolic steroids and other drugs can slow muscle degeneration until a better treatment (or cure) is found.


Calcium blockers
These have also been tried to stem the debilitating effects of DMD. Calcium-a mineral that is found in all tissues of the body-is known to harm cells when it leaks in through membrane channels. But the extent to which such drugs can prevent dystrophinopathy (given that the entire membrane is extremely leaky, and not just normal membrane channels) is questionable. Another factor that complicates the use of channel blockers for DMD is the fact that prednisone can lead to osteoporosis, which usually requires oral calcium supplements. However, the amount of calcium in tissues is regulated separately from the amount absorbed from the gut, and precious calcium will be removed from bone when insufficient amounts are ingested in the diet.

Gentamycin
This is an antibiotic that has figured prominently in recent news items about cases of DMD due to premature "stop codons." In these cases the complete gene for dystrophin is never "decoded" or translated so that this critical muscle protein is not made, or at least not made in full form. Research on mdx mice that simulate human DMD has shown that when gentamycin is administered, the premature stop codon is somehow ignored so that the entire gene transcript can be "read" and dystrophin can be produced. A preliminary trial on DMD young men is underway, and hopes are high that this will work in humans as well as it did in the model mice. Unfortunately, this treatment would only work for those instances (about 10% of all DMD cases) in which the gene defect is a premature stop codon.



    


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