If you are a victim of someone who is spreading malicious lies about you, and you are somehow damaged as a result, you may have a claim for defamation of character. There is a cause of action available in most states' courts for defamation of character.
The elements of in Missouri are: 1) publication, 2) of a defamatory statement, 3) that identifies the plaintiff, 4) that is false, 5) that is published with the requisite degree of fault (negligence), and 6) damages the plaintiff's reputation. Nazeri v. Missouri Valley College, 860 S.W.2d 303 (Mo. banc 1993). If the person being defamed is a public figure, then the degree of fault rises to actual malice to obtain damages.
Missouri courts are stricter than some other state courts, because Missouri courts require proof of actual damages in order to recover in the defamation case. There must be harm to the victim's reputation, and that harm must be measured in some economic way. If a person can prove he lost out on a job opportunity, or that his business suffered a loss of revenue because of the lies, that is one way to prove economic loss. Some states, however, do not require proof of economic loss or even harm to reputation, if the lies that are being spread reach to a certain level of egregiousness. For instance, in some states, a person can make a case of libel per se against a person spreading lies about him if the person spreading the lie alleges a crime, or alleges that the person has an infectious disease, or makes a statement that impeaches the person in his trade or profession. But in Missouri, the burden of proof is much higher.
Punitive damages are also recoverable in a Missouri defamation claim. But, in order to recover punitive damages, the plaintiff has to prove with clear and convincing evidence that Defendant acted with malice (evil motive or reckless disregard).
Here is a great article from the Missouri Bar which gives you more information.