Medkit

Medkits also known as Medic Kits are the most commonly used healing items which are easily available at any vendor. They replenish health to every character in your party up to slightly over 1/4 of life and cures infection. To use them open the inventory and in the weapon section select the medic kits and press the fire button on them. If you and your party's health is full, the medic kit won't do anything. If you use it when near full life with you and your party members, you would waste a valuable item.

Where it is located

 * Doing a holdup and successfully doing it will allow you to get into the secret stash and it may have one
 * Destorying an ambulance will result in a several of medkit laying around
 * Killing anyone with boxes may result in a medkit
 * Buying it from various vendors

Most Effective Way to Use
You should use it when you have and party is at critical health or if your survivor(s) have an effective weapon that is about to die. Let any survivor with knives die until you have a higher weapon level, they usually serve as a decoy since they back up from any horde of zombies during a takeover.