There are two types of medicines, one for rate control when in tachycardia and one for rhythm regulation. Whichever of those two you need your cardiologist and/or EP will tell you.

Metoprolol interferes with adrenergic receptors in the heart. It prevents reactivity in the myocytes which makes them ramp up more easily and speed up their output.
https://cvpharmacology.com/cardioinhibitory/beta-blockers
The many anti-arrhythmics do the same thing, but with calcium, sodium, and potassium.
https://my.clevelandclinic.org/health/drugs/22867-what-are-antiarrhythmics
I'm not aware of a medicine that treats ventricular tachycardia per se, but there may be one. Either that or a pacemaker.

Edit (added after looking): https://www.drugs.com/condition/ventricular-tachycardia.html