Penicillin VK is a potassium salt of penicillin V. Strep throat is typically treated with antibiotics, such as either penicillin or amoxicillin. Treatment when infected is with antibiotics such as doxycycline, penicillin, or ceftriaxone. Amoxicillin may be replaced with metronidazole in patients who are allergic to penicillin. Treatment is typically with antibiotics including&colon; azithromycin by mouth or benzathine penicillin by injection. Reports of successful treatment with parenteral penicillin or ampicillin exist. In cases of penicillin allergy, doxycycline is used. Cefalexin is a useful alternative to penicillins in patients with penicillin intolerance. In those who are allergic to penicillin, cephalosporins or macrolides may be used. It may be used by those who are allergic to penicillin or cephalosporins. Trimethoprim-sulfamethoxazole has been shown effective in patients allergic to penicillin. Semisynthetic penicillins are prepared starting from the penicillin nucleus 6-APA. He is allergic to feathers and penicillin. It is generally safe in those who are allergic to penicillin. It should not be used in people who are allergic to penicillin.