Penicillin v potassium tablets are effective in treating mild to moderate infections caused by sensitive strains of bacteria, including tonsillitis, pharyngitis, scarlet fever, and dengue caused by streptococcus; bronchitis, pneumonia, otitis media, and sinusitis caused by pneumococcus; and skin and soft tissue infections caused by staphylococcus. It can also prevent the recurrence of rheumatic fever and infective endocarditis, as well as spirochete infections. Common adverse reactions to penicillin v potassium tablets are nausea and vomiting, epigastric discomfort, diarrhea, and black hairy tongue. Allergic reactions include rash, urticaria, serum sickness-like reactions, laryngeal edema, drug fever, and eosinophilia. In a few patients, hemolytic anemia, leukopenia or thrombocytopenia, transient increase in serum aminotransferase, neurotoxicity, and nephrotoxicity may occur. Prolonged heavy drug use may also cause penicillin-resistant, Staphylococcus aureus, gram-negative bacilli, and Candida albicans coinfections. In addition, patients with a history of allergy to penicillins and a positive reaction to penicillin skin test are prohibited, patients with infectious mononucleosis are prohibited, patients with asthma, eczema, hay fever, urticaria and other allergic diseases should be used with caution, renal hypogonadism should be used with caution, the elderly should be used with caution, pregnant women should be used with caution, lactating women should be used with caution or suspension of breastfeeding, and the use of children’s medication is not clear. If you need to take penicillin v potassium tablets, please consult a professional doctor and follow the doctor’s instructions, do not blindly use drugs.