Can Amoxicillin cause drug hypersensitivity?

ADVERSE REACTIONS The following are discussed in more detail in other sections of the labeling: • Anaphylactic reactions [see Warnings and Precautions ( Error! Hyperlink reference not valid. )] • Severe Cutaneous Adverse Reactions [see Warnings and Precautions ( Error! Hyperlink reference not valid. )] • Drug-Induced Enterocolitis Syndrome (DIES) [see Warnings and Precautions ( Error! Hyperlink reference not valid. )] • Clostridioides difficile -Associated Diarrhea (CDAD) [see Warnings and Precautions ( Error! Hyperlink reference not valid. )] The most common adverse reactions (greater than 1%) observed in clinical trials of amoxicillin capsules, amoxicillin tablets or for oral suspension were diarrhea, rash, vomiting, and nausea. ( Error! Hyperlink reference not valid. ) To report SUSPECTED ADVERSE REACTIONS, contact Teva at 1-888-838-2872 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The most common adverse reactions (greater than 1%) observed in clinical trials of amoxicillin capsules, amoxicillin tablets or for oral suspension were diarrhea, rash, vomiting, and nausea. Triple therapy: The most frequently reported adverse events for patients who received triple therapy (amoxicillin/clarithromycin/ lansoprazole) were diarrhea (7%), headache (6%), and taste perversion (5%). Dual therapy: The most frequently reported adverse events for patients who received double therapy amoxicillin/lansoprazole were diarrhea (8%) and headache (7%). For more information on adverse reactions with clarithromycin or lansoprazole, refer to the Adverse Reactions section of their package inserts. 6.2 Postmarketing Experience In addition to adverse events reported from clinical trials, the following events have been identified during postmarketing use of penicillins. Because they are reported voluntarily from a population of unknown size, estimates of frequency cannot be made. These events have been chosen for inclusion due to a combination of their seriousness, frequency of reporting, or potential causal connection to amoxicillin. • Infections and Infestations: Mucocutaneous candidiasis. • Gastrointestinal: Drug-induced enterocolitis syndrome (DIES), black hairy tongue, and hemorrhagic/pseudomembranous colitis. Onset of pseudomembranous colitis symptoms may occur during or after antibacterial treatment [see Warnings and Precautions ( Error! Hyperlink reference not valid. )] . • Immune: Hypersensitivity reactions, anaphylactic/anaphylactoid reactions (including shock), angioedema, serum sickness-like reactions (urticaria or skin rash accompanied by arthritis, arthralgia, myalgia, and frequently fever), hypersensitivity vasculitis [see Warnings and Precautions ( Error! Hyperlink reference not valid. )] . • Skin and Appendages: Rashes, pruritus, urticaria, erythema multiforme, SJS, TEN, DRESS, AGEP, exfoliative dermatitis, and linear IgA bullous dermatosis. • Liver: A moderate rise in AST and/or ALT has been noted, but the significance of this finding is unknown. Hepatic dysfunction including cholestatic jaundice, hepatic cholestasis and acute cytolytic hepatitis have been reported. • Renal: Crystalluria has been reported [see Overdosage ( Error! Hyperlink reference not valid. )] . • Hemic and Lymphatic Systems: Anemia, including hemolytic anemia, thrombocytopenia, thrombocytopenic purpura, eosinophilia, leukopenia, and agranulocytosis have been reported. These reactions are usually reversible on discontinuation of therapy and are believed to be hypersensitivity phenomena. • Central Nervous System: Reversible hyperactivity, agitation, anxiety, insomnia, confusion, convulsions, behavioral changes, aseptic meningitis, and/or dizziness have been reported. • Miscellaneous: Tooth discoloration (brown, yellow, or gray staining) has been reported. Most reports occurred in pediatric patients. Discoloration was reduced or eliminated with brushing or dental cleaning in most cases.

WARNINGS AND PRECAUTIONS • Anaphylactic reactions: Serious and occasionally fatal anaphylactic reactions have been reported in patients on penicillin therapy, including amoxicillin. Discontinue Amoxicillin for Oral Suspension, USP if a reaction occurs ( 5.1 ). • Severe cutaneous adverse reactions (SCAR): Monitor closely. Discontinue if rash progresses. ( 5.2 ) • Drug-induced enterocolitis syndrome (DIES) has been reported with amoxicillin use. If this occurs, discontinue Amoxicillin for Oral Suspension, USP and institute appropriate therapy. ( 5.3 ) • Clostridioides difficile -associated diarrhea (CDAD) (ranging from mild diarrhea to fatal colitis): Evaluate if diarrhea occurs. ( 5.4 ) 5.1 Anaphylactic Reactions Serious and occasionally fatal hypersensitivity (anaphylactic) reactions have been reported in patients on penicillin therapy including amoxicillin. Although anaphylaxis is more frequent following parenteral therapy, it has occurred in patients on oral penicillins. These reactions are more likely to occur in individuals with a history of penicillin hypersensitivity and/or a history of sensitivity to multiple allergens. There have been reports of individuals with a history of penicillin hypersensitivity who have experienced severe reactions when treated with cephalosporins. Before initiating therapy with amoxicillin, careful inquiry should be made regarding previous hypersensitivity reactions to penicillins, cephalosporins, or other allergens. If an allergic reaction occurs, amoxicillin should be discontinued, and appropriate therapy instituted. 5.2 Severe Cutaneous Adverse Reactions Amoxicillin may cause severe cutaneous adverse reactions (SCAR), such as Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), drug reaction with eosinophilia and systemic symptoms (DRESS), and acute generalized exanthematous pustulosis (AGEP). If patients develop skin rash they should be monitored closely, and amoxicillin discontinued if lesions progress. 5.3 Drug-Induced Enterocolitis Syndrome (DIES) Drug-induced enterocolitis syndrome (DIES) has been reported with amoxicillin use [ see Adverse Reactions ( 6.2 ) ], with most cases occurring in pediatric patients ≤18 years of age. DIES is a non-IgE mediated hypersensitivity reaction characterized by protracted vomiting occurring 1 to 4 hours after drug ingestion in the absence of skin or respiratory symptoms. DIES may be associated with pallor, lethargy, hypotension, shock, diarrhea within 24 hours after ingesting amoxicillin, and leukocytosis with neutrophilia. If DIES occurs, discontinue Amoxicillin for Oral Suspension, USP and institute appropriate therapy. 5.4 Clostridioides difficile -Associated Diarrhea (CDAD) Clostridioides difficile -associated diarrhea (CDAD) has been reported with use of nearly all antibacterial agents, including amoxicillin, and may range in severity from mild diarrhea to fatal colitis. Treatment with antibacterial agents alters the normal flora of the colon leading to overgrowth of C. difficile . C. difficile produces toxins A and B which contribute to the development of CDAD. Hypertoxin-producing strains of C. difficile cause increased morbidity and mortality, as these infections can be refractory to antimicrobial therapy and may require colectomy. CDAD must be considered in all patients who present with diarrhea following antibacterial use. Careful medical history is necessary since CDAD has been reported to occur over 2 months after the administration of antibacterial agents. If CDAD is suspected or confirmed, ongoing antibacterial use not directed against C. difficile may need to be discontinued. Appropriate fluid and electrolyte management, protein supplementation, antibacterial treatment of C. difficile , and surgical evaluation should be instituted as clinically indicated. 5.5 Development of Drug-Resistant Bacteria Prescribing amoxicillin in the absence of a proven or strongly suspected bacterial infection or prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria. 5.6 Skin Rash in Patients with Mononucleosis A high percentage of patients with mononucleosis who receive amoxicillin develop an erythematous skin rash. Thus, amoxicillin should not be administered to patients with mononucleosis. 5.7 Phenylketonurics Amoxicillin chewable tablets contain aspartame which contains phenylalanine. Each 200 mg chewable tablet contains 1.82 mg phenylalanine; each 400 mg chewable tablet contains 3.64 mg phenylalanine. The oral suspension formulations of amoxicillin do not contain phenylalanine and can be used by phenylketonurics.