Anaphylactic reactions, penicillins

After administering penicillin IM in the outpatient setting, the nurse asks the client to wait in the area for at least 30 minutes Anaphylactic reactions are most likely to occur within 30 minutesafter injection. 

The p-lactams (penicillins and their derivatives) are the drugs which most frequently cause IgE-mediated anaphylactic reactions. Diagnosis is based on skin tests. To date, the best vaUdated in vitro diagnostic methods are specific IgE and BAT. As for the determination of specific IgE using ImmimoCap (Phadia AB, Uppsala, Sweden), the sensitivity of the technique in the diagnosis of immediate reaction to (3-lactams with positive skin test ranges, according to the study, from 37 to 54% with a specificity of between 83 and 100% [23,24]. 

Some types of allergic reaction, for example immediate or delayed-type skin allergies, serum-sickness-like reactions and anaphylactic reactions, may occur in a proportion of patients given penicillin treatment. There is some, but not complete, cross-allergy with cephalosporins. 

Hypersensitivity reactions Serious and occasionally fatal hypersensitivity (anaphylactic) reactions have been reported in patients receiving therapy with beta-lactams. These reactions are more likely to occur in individuals with a history of sensitivity to multiple allergens. There have been reports of individuals with a history of penicillin P.903... 

Hameed TK, Robinson JL. Review of the use of cephalosporins in children with anaphylactic reactions from penicillins. Can J Infect Dis 2002 13(4) 253-8. 

Contraindications History of anaphylactic reaction to penicillins or hypersensitivity to cephalosporins... 

Contraindications Anaphylactic reaction to penicillins, history of hypersensitivity to cephalosporins or any one of its components. 

The newer derivatives seem less likely to cause hypersensitivity reactions, perhaps because the protein adducts generated are shorter lived. All four types of hypersensitivity reaction have been observed with penicillin. Thus, high doses may cause hemolytic anemia and immune complex disease and cell-mediated immunity may give rise to skin rashes and eruptions, and the most common reactions are urticaria, skin eruptions, and arthralgia. Antipenicillin IgE antibodies have been detected consistently with an anaphylactic reaction. The anaphylactic reactions (type 1 see above), which occur in 0.004% to 0.015% of patients, may be life threatening. 

One of the primary problems with penicillin drugs is the potential for allergic reactions.65 Hypersensitivity to penicillin is exhibited by skin rashes, hives, itching, and difficult breathing. In some individuals, these reactions may be minor and can often be resolved by changing the type of penicillin or the method of administration. In others, however, penicillin hypersensitivity may be severe and lead to an anaphylactic reaction (severe bronchoconstriction and cardiovascular collapse). 

A classic example of a drug that forms haptenic derivatives is penicillin. Penicillin and its structural analogs are widely used antibiotics that are, unfortunately, responsible for more allergic reactions than any other class of drug (1-10 percent of the population). Although all four types (see later discussion) of allergic reactions have been observed with penicillin, type I anaphylactic reactions, which can occur with a frequency of 1/15,000 patients, may be life-threatening. 

Hypersensitivity is the most important side-effect of penicillins and is manifest usually by rashes and rarely anaphylactic reactions. Allergic reactions to penicillins occur in 1-10% of exposed individuals anaphylactic reactions occur in fewer than 0.05% treated patients (Joint Formulary Committee, 2008). General side-effects of antibiotics include nausea, vomiting, abdominal pain, diarrhoea, headache and vaginitis. 

Allergic responses to drugs are mediated by the release of histamine or histamine-like substances, and they commonly present as skin rashes, particularly urticaria. More serious hypersensitivity responses include bronchospasm or the acute, explosive anaphylactic reaction with cyanosis and cardiovascular collapse. A delayed reaction known as serum sickness, although more often associated with such drugs as the penicillins and cephalosporins rather than with serum, manifests clinically 7 to 10 days after receiving the drug or serum as fever, malaise, joint pains, and urticarial skin rashes. 

With penicillins, opening of the p-lactam bond is possible. The resulting penicilloyl group binds as a hapten to a protein. This may lead to an Ig-E mediated anaphylactic reaction, manifested on the skin as urticaria. 

An estimated 1-17% of the population of the United States is considered at risk for having an anaphylactic reaction if exposed to one or more allergens, especially penicillin and insect stings. Most affected individuals successfully avoid such allergens and will never experience anaphylaxis. Of those who actually experience anaphylaxis, up to 1% may die as a result. Anaphylaxis results in approximately 18 deaths per year in the USA (compared to 2.4 million deaths from all other causes each year). The most common presentation includes sudden cardiovascular collapse (88% of reported cases of severe anaphylaxis). 

Cullen DJ. Severe anaphylactic reaction to penicillin during halothane anaesthesia. A case report. Br J Anaesth 1971 43(4) 410-12. 

Dry J, Leynadier F, Damecour C, Pradalier A, Herman D. Reaction pseudo-anaphylactique a la procaine-penicilline G. Trois cas de syndrome de Hoigne. [Pseudo-anaphylactic reaction to procaine-penicillin G. 3 cases of Hoigne s syndrome.] Nouv Presse Med 1976 5(22) 1401-3. 

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