Penicillin VK is not effective in treating viral infections. The antibiotic works by infiltrating the structure of the bacteria and killing it. The bacteria can fight back by producing enzymes called beta-lactamases, which can attack the penicillin and make it less effective. To counter this, the penicillin is usually prescribed in combination with an inhibitor. The inhibitor keeps the enzyme from developing and so the penicillin is able to do its job.
Resistance to penicillin can occur. When the antibiotic is overused, bacteria starts to build up a tolerance for it. Once that occurs, medical care providers have to treat infections with other types of antibiotics. Side effects for penicillin VK are usually mild. Upset stomach, mouth sores and diarrhea are the most common side effects. In some rare cases, the patient might develop a hairy tongue. The tongue usually clears without the need for medical intervention. It is important to maintain good dental hygiene while taking penicillin to lower the chances of experiencing a hairy tongue. More serious side effects, such as joint pain, need to be reported immediately to the doctor.Learn more about Medications & Vitamins