Motor systems, drugs acting

The phenothiazine drugs act by blocking dopamine receptors in the limbic system. Unfortunately, phenothiazines also block dopamine in the striatum, upsetting the balance between dopamine and acetylcholine and resulting in side-effects known as extrapyramidal motor signs. These signs include bradykinesia, muscle... 

Colonic transit time is only slightly affected by food, but is redueed under stress. Studies have shown that drugs, which act on the parasympathetie or sympathetie nervous system, affeet the propulsive motor aetivity, thereby influeneing the eolonie transit time [12]. Although not significantly affected by most diseases [13], the transit time is shorter in patients who complain of diarrhea and longer in patients with eonsti-pation. 

Because these drugs relax muscles, they can cause prolonged muscle weakness and motor coordination problems. Some of these drugs also act on the central nervous system and cause side effects such as confusion, dizziness, sedation, nausea, and dry mouth. Most muscle relaxants are prescribed... 

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