Allopurinol partially prevents disuse muscle atrophy in mice and humans.

Disuse muscle wasting will likely affect everyone in his or her lifetime in response to pathologies such as joint immobilization, inactivity or bed rest. There are no good therapies to treat it. We previously found that allopurinol, a drug widely used to treat gout, protects muscle damage after exhaustive exercise and results in functional gains in old individuals. Thus, we decided to test its effect in the prevention of soleus muscle atrophy after two weeks of hindlimb unloading in mice, and lower leg immobilization following ankle sprain in humans (EudraCT: 2011-003541-17). Our results show that allopurinol partially protects against muscle atrophy in both mice and humans. The protective effect of allopurinol is similar to that of resistance exercise which is the best-known way to prevent muscle mass loss in disuse human models. We report that allopurinol protects against the loss of muscle mass by inhibiting the expression of ubiquitin ligases. Our results suggest that the ubiquitin-proteasome pathway is an appropriate therapeutic target to inhibit muscle wasting and emphasizes the role of allopurinol as a non-hormonal intervention to treat disuse muscle atrophy.

Safety and efficacy of botulinum toxin A for the treatment of spasticity in amyotrophic lateral sclerosis: results of a pilot study.

Spasticity can be a very disabling problem in some amyotrophic lateral sclerosis (ALS) phenotypes, such as upper motor neuron-dominant ALS (UMN-D ALS) and primary lateral sclerosis (PLS). Our aim is to describe the safety and efficacy of botulinum toxin A (BoTox-A) for improving gait in those ALS phenotypes. UMN-D ALS and PLS outpatients experiencing gait disturbances, secondary to moderate-to-severe spasticity despite optimized oral medication, were offered BoTox-A treatment. Stretching exercises were indicated to complement BoTox-A effect, and ankle-foot orthotics were prescribed when appropriate. Tolerance (muscle strength, disease progression rate) and efficacy (10-m walk test) were measured at baseline and after treatment. Eight out of 122 ALS outpatients were offered BoTox-A treatment. One declined and the other seven were administered BoTox-A in the lower limbs, every 5-8 months. All of them experienced improvement in the clinical outcome and all but one referred subjective improvement. Moreover, after a median follow-up of 16 months and three injections, BoTox-A effect was maintained with no adverse events. This study provides class IV evidence that BoTox-A is safe , and could be beneficial in the short term and long term in a subset of ALS patients with moderate-to-severe spasticity.