Are there any medications that help with teeth grinding, I hate using the guard?

Not really. Teeth grinding or clenching, called bruxism can cause painful aches in the upper jaw, wear and tear on the teeth and sometimes poor sleep. The guard is the first line for bruxism. Medications are only helpful in some cases and are prescribed a by a physician. Sometimes, bruxism may be associated with increased levels of stress and addressing that may be helpful.
Not directly . . . . Many things can cause clenching and grinding of the teeth (technically referred to as bruxism). Nocturnal bruxing happens at night, and can be related to stress, anxiety, or the bodies natural response to teeth that do not fit together correctly. If your bruxism is stress related, there are medications that can treat the anxiety, which could lessen the grinding.
Some are helpful... Guard is a great first line, but there are other options... Getting a full analysis to determine why you are grinding, and if you might benefit from a bite equilibration is good start... Obstructive sleep disorders can make it difficult to tolerate a guard... A muscle relaxant (flexeril) could reduce the force of your clench, and Elavil (amitriptyline) has been proven to inhibit clenching and grinding for some...
Diagnose. First lets determine why! is there a malocclusion, is it habitual, what stressors are involved?Then we can address how to treat.
No. Sleep medication may actually worsen your grinding. Sometimes with adjustments the guard can become more comfortable. You may consider seeing a dentist who has pankey mastey training and invisalign. Training.
A few. In some cases, your doctor may suggest taking a muscle relaxant before bedtime, for a short period of time. Elavil (amitriptyline) has been proven to inhibit clenching and grinding for some. Botox injections may help some people with severe bruxism who don't respond to other treatments.
No pill. Nothing you can take that will stop bruxism (teeth grinding). Have general dentist refer you to orthodontist to check your occlusion. Bruxism seen in many patients that have malocclusions. Talk to your dentist about a different type of mouth guard.
Bruxism. Unfortunately, bruxism or grinding your teeth appears to be something that is exceptionally common for humans. The night guard helps to provide a "skating rink" to protect your teeth from the damage of bruxism at night. We'd rather you grind up the plastic than your teeth.
No. A well designed lower bite guard is easy to get used to and does not affect your entire system as any drug will.