Title: Keflex and Sulfa Allergies | Healthfully
Headings: 
Sulfa Drugs
Sulfa Drugs and Skin Allergic Reaction
Sulfonamide Drug Hypersensitivity Syndrome
Keflex Allergic Reaction

Content: Keflex and Sulfa Allergies | Healthfully
Keflex is a broad-spectrum cephalosporin antibiotic used to treat upper respiratory infections, urinary tract infections, as well as ear, bone, and skin infections. This antibiotic exhibits bactericidal properties by interfering with formation of the cell wall, causing osmotic imbalance and ultimately cell lysis. Sulfa drugs or sulfonamides are bactereriostatic agents derived from sulphanilamide 2. These drugs inhibit the growth of bacterial organisms by inhibiting folic acid biosynthesis and consequently the synthesis of deoxyribonucleic acid, or DNA, and ribonucleic acid, or RNA. Individuals who experience an allergic reaction to these antibiotics should discontinue the drug immediately and seek immediate medical help. Sulfa Drugs
Sulfa drugs, also known as sulfonamides, are chemical compounds that contain a SO2NH2 moiety 2. Based on their chemical structure, these drugs are divided into three classes, however, they all have the same mechanism of action. These drugs inhibit bacterial growth by acting as a competitive inhibitor to the enzyme, p-aminobenzoic acid. PABA is required for the biosynthesis of folic acid, which in turn is required for the synthesis of nucleic acids, and ultimately, DNA and RNA. Bacterial organisms sensitive to sulfa drugs are unable to synthesize folic acid in the presence of these antibiotics, and thus are unable to synthesize the compounds necessary for cellular growth and multiplication.