Penicillin should be used with caution in individuals with histories of significant allergies and/or asthma. All degrees of hypersensitivity, including fatal anaphylaxis, have been observed with oral penicillin. I'm allergic to penicillin and sulfa. Dentist prescribed Clindamycin 150 mg for 10 days for infection in my tooth. Got hives, rash, swollen lips and extreme itching and blotches from head to toe. Drug allergies are a hypersensitive reaction of the immune system to certain medications we may take. Potentially life-threatening reactions to a drug may occur. There are some important things to consider before taking antibiotics. Penicillin. Don't take one of the penicillin-based antibiotics if you've had an allergic reaction to them in the past. The Basics and Beyond the Basics. The Basics patient education pieces are written in plain language,… reactions to an allergy specialist. OAS is IgE-mediated and considered a form of contact allergy that develops in patients sensitized to pollens. HOW SUPPLIED. Penicillin/Penicillin G Potassium Intravenous Inj Sol: 50mL, 1000000U, 2000000U, 3000000U Penicillin/Penicillin G Potassium/Penicillin G Sodium/Pfizerpen Intravenous Inj Pwd F/Sol: 5000000U, 20000000U Some Medications are Deadly to Guinea Pigs. While all antibiotics will affect the gut flora of a guinea pig, some are deadly and can cause a fatal enterotoxemia. No! Do not take any drug containing cephalosporins if you are allergic to penicillin. This drug is a cousin let's say, to penicillin. In my case it causes a severe reaction, and I was hospitalized for 5 days by taking a drug named Vantin. a ceph antibiotic. Keflex is a cephalosporins drug and there have been instances of cross allergies between the two drugs. If you are allergic to penicillin it is usually best to avoid Keflex too. [Your email has been verified.] To place a successful order you will need to complete your account profile. If you have any questions or need assistance please don't hesitate to give us a call at 1-800-630-3214.