Antispasmodic agents are a group of medications typically used to treat uncontrollable, sudden muscle contractions, called spasms. There are several different types of these drugs, which have different specific uses and purposes. Humans have several muscle types, and two of these, known as skeletal and smooth muscle, often require different medications to control potential spasms.
Skeletal muscles are connected to bones, and allow joints to move voluntarily. Several antispasmodic agents exist to treat conditions involving these muscles, including cyclobenzaprine, tizanidine, and carisoprodol. These drugs have different mechanisms that allow them to be effective, but many of these compounds seem to work by mediating nerve signal messages that normally control muscle movement.
Smooth muscle is another major class in the human body, and includes the muscle of gut and intestines; normally, the movement of these muscles help to move food, waste, and other substances through the body. The two types of antispasmodic agents that regulate these muscle movements include antimuscarinics and smooth muscle relaxants. Antimuscarinics are a type of antispasmodic agents that affect sites on certain cells called muscarinic receptors. By blocking these receptors, they prevent messages from being sent to smooth muscle cells that would normally tell them to contract. Spasms are caused by inappropriate contractions, so these drugs can prevent the cause of these movements in many cases; common medications in this class include hyoscyamine and atropine.
The other class of antispasmodic agents that affect this type of muscle are called smooth muscle relaxants. Compounds in this family include peppermint oil and mebeverine. These substances also bind to receptors located on the surface of smooth muscles, but unlike antimuscarinics, these compounds directly cause muscle relaxation after they bind. Relaxing the smooth muscles can often help to prevent contractions from occurring.
Other antispasmodic agents exist that do not fall into these general categories, and which function in different ways to relieve muscle contractions. Active substances found in cannabis, for example, have been found by some research to be effective in reducing nausea by acting as an antispasmodic, at least among some individuals. Papaverine may prevent spasms by inhibiting the action of certain proteins that are involved in the process of smooth muscle movement. Usually, however, conventional skeletal and smooth muscle agents are used in treatment by most individuals with these conditions, although some people prefer non-traditional and herbal compounds for their therapeutic purposes.