Cutaneous adverse reactions to clindamycin: results of skin tests and oral exposure

Scientific Rationale and Clinical Basis for Clindamycin Use in the Treatment of Dermatologic Disease

Clindamycin is a highly effective antibiotic of the lincosamide class. It has been widely used for decades to treat a range of skin and soft tissue infections in dermatology and medicine. Clindamycin is commonly prescribed for acne vulgaris, with current practice standards utilizing fixed-combination topicals containing clindamycin that prevent Cutibacterium acnes growth and reduce inflammation associated with acne lesion formation. Certain clinical presentations of folliculitis, rosacea, staphylococcal infections, and hidradenitis suppurativa are also responsive to clindamycin, demonstrating its suitability and versatility as a treatment option. This review describes the use of clindamycin in dermatological practice, the mechanism of protein synthesis inhibition by clindamycin at the level of the bacterial ribosome, and clindamycin's anti-inflammatory properties with a focus on its ability to ameliorate inflammation in acne. A comparison of the dermatologic indications for similarly utilized antibiotics, like the tetracycline class antibiotics, is also presented. Finally, this review addresses both the trends and mechanisms for clindamycin and antibiotic resistance, as well as the current clinical evidence in support of the continued, targeted use of clindamycin in dermatology.

The Role of Patch Testing in Evaluating Delayed Hypersensitivity Reactions to Medications

Confirming drug imputability is an important step in the management of cutaneous adverse drug reactions (CADR). Re-challenge is inconvenient and in many cases life threatening. We review the literature on ideal patch testing technique for specific CADRs. Testing should be performed approximately 3 months after the resolution of the eruption using standard patch testing techniques. Commercially available patch test preparations are available for a minority of drugs, so in most cases, testing should be performed with the drug at various recommended concentrations and in different vehicles. Testing to all known excipients, such as dyes, vehicles and preservatives is also important. Immunosuppressive medications should be discontinued or down titrated to the lowest tolerable dose to decrease the risk of false negative reactions. We provide an overview of expert recommendations and extant evidence on the utility of patch testing for identifying the culprit drug in common CADRs and for specific drug or drug classes. Overall, there appears to be significant variability in the patch test positivity of different drugs, which is likely the result of factors intrinsic to the drug such as dermal absorption (as a function of lipophilicity and molecular size) and whether the drug itself or a downstream metabolite is implicated in the immune reaction. Drugs with high patch test positivity rates include beta-lactam antibiotics, aromatic anticonvulsants, phenytoin, and corticosteroids, among others. Patch testing positivity varies both as a function of the drug and type of CADR. The sum of the evidence suggests that patch testing in the setting of morbilliform eruptions, fixed drug eruption, acute generalized exanthematous pustulosis, and possibly also drug-induced hypersensitivity syndrome, photoallergic and eczematous reactions may be worthwhile, although utility of testing may vary on the specific drug in question for the eruption. It appears to be of limited utility and is not recommended in the setting of other complex CADR, such as SJS/TEN and leukocytoclastic vasculitis.

Antibiotic Treatment, Mechanisms for Failure, and Adjunctive Therapies for Infections by Group A Streptococcus

Group A Streptococcus (GAS; Streptococcus pyogenes) is a nearly ubiquitous human pathogen responsible for a significant global disease burden. No vaccine exists, so antibiotics are essential for effective treatment. Despite a lower incidence of antimicrobial resistance than many pathogens, GAS is still a top 10 cause of death due to infections worldwide. The morbidity and mortality are primarily a consequence of the immune sequelae and invasive infections that are difficult to treat with antibiotics. GAS has remained susceptible to penicillin and other β-lactams, despite their widespread use for 80 years. However, the failure of treatment for invasive infections with penicillin has been consistently reported since the introduction of antibiotics, and strains with reduced susceptibility to β-lactams have emerged. Furthermore, isolates responsible for outbreaks of severe infections are increasingly resistant to other antibiotics of choice, such as clindamycin and macrolides. This review focuses on the challenges in the treatment of GAS infection, the mechanisms that contribute to antibiotic failure, and adjunctive therapeutics. Further understanding of these processes will be necessary for improving the treatment of high-risk GAS infections and surveillance for non-susceptible or resistant isolates. These insights will also help guide treatments against other leading pathogens for which conventional antibiotic strategies are increasingly failing.

Antimicrobial Desensitization: A Review of Published Protocols

Antimicrobial desensitization represents a last-line option for patients with no alternative therapies, where the benefits of this intensive process must outweigh the potential harm from drug exposure. The goal of antimicrobial desensitization procedures is to establish a temporary state of tolerance to drugs that may otherwise cause hypersensitivity reactions. While no universal antimicrobial desensitization protocols exist, this review critically analyzes previously published desensitization protocols. The purpose of this review is to provide a greater insight for clinicians and institutions to ensure desensitization procedures are efficacious while minimizing potential for patient harm. With an increasing rate of antimicrobial resistance and the critical need to preserve antimicrobial agents, desensitization may represent another option in our antimicrobial stewardship toolkit.

Angiotensin-converting Enzyme Inhibitor and Other Drug-associated Angioedema

Nonsteroidal antiinflammatory agents, β-lactam antibiotics, non-β lactam antibiotics, and angiotensin-converting enzyme inhibitors are the most common classes of drugs that cause angioedema. Drug-induced angioedema is known to occur via mechanisms mediated by histamine, bradykinin, or leukotriene, and an understanding of these mechanisms is crucial in guiding therapeutic decisions. Nonallergic angioedema occurs in patients with genetic variants that affect metabolism or synthesis of bradykinin, substance P, prostaglandins, or leukotrienes, or when patients are taking drugs that have synergistic mechanisms. The mainstay in treatment of nonallergic drug-induced angioedema is cessation of the offending agents.

Isolation and identification of two unknown impurities from the raw material of clindamycin hydrochloride

Clindamycin hydrochloride belongs to the antibiotic family of lincomycin. It has the same antibacterial spectrum as lincomycin, but the antibacterial activity is four to eight times stronger than that of lincomycin. There have been some adverse reactions in clinical use of clindamycin hydrochloride and its finished drug products. The impurities in drugs are directly related to their safety. In this study, two unknown impurities were isolated from the raw material of clindamycin hydrochloride through various chromatographic methods. Their structures were identified as clindamycin isomer (impurity 1) and dehydroclindamycin (impurity 2) by mass spectrometry and NMR spectroscopy. Both of them were found for the first time. The two impurities exhibit a similar but lower antibacterial activity compared with clindamycin hydrochloride.

Hypersensitivity reactions to non beta-lactam antimicrobial agents, a statement of the WAO special committee on drug allergy

Antibiotics are used extensively in the treatment of various infections. Consequently, they can be considered among the most important agents involved in adverse reactions to drugs, including both allergic and non-allergic drug hypersensitivity [J Allergy Clin Immunol 113:832–836, 2004]. Most studies published to date deal mainly with reactions to the beta-lactam group, and information on hypersensitivity to each of the other antimicrobial agents is scarce. The present document has been produced by the Special Committee on Drug Allergy of the World Allergy Organization to present the most relevant information on the incidence, clinical manifestations, diagnosis, possible mechanisms, and management of hypersensitivity reactions to non beta-lactam antimicrobials for use by practitioners worldwide.

Clindamycin-induced acute kidney injury: large biopsy case series

BACKGROUND

While clindamycin-induced acute kidney injury (AKI) is uncommon, it has occurred more frequently in recent years.

SUMMARY

We investigated 24 patients diagnosed with clindamycin-induced AKI retrospectively. The dosage of clindamycin was 1.0-1.5 g/day. Fifteen patients had episodes of gross hematuria, but fever, skin rash and eosinophilia were rare. Urine analysis revealed mild proteinuria and severe tubular dysfunction. Twenty-three patients were diagnosed with AKI stage 3 upon admission. The clindamycin lymphocyte transformation assay was positive for 63.2% of the patients. Acute interstitial nephritis (AIN) and acute tubular necrosis (ATN) were proven by renal biopsy, and renal insufficiency appeared to result from tubular toxicity and drug crystals. In the majority (87.5%) of the patients, AKI was severe and required renal replacement therapy, but all of their renal function recovered significantly 2 months after discharge. Clindamycin-induced AKI is largely reversible and has episodes of gross hematuria. Renal biopsies confirmed AIN or ATN in these patients.

Update on the management of antibiotic allergy

Drug allergy to antibiotics may occur in the form of immediate or non-immediate (delayed) hypersensitivity reactions. Immediate reactions are usually IgE-mediated whereas non-immediate hypersensitivity reactions are usually non-IgE or T-cell mediated. The clinical manifestations of antibiotic allergy may be cutaneous, organ-specific (e.g., blood dyscracias, hepatitis, interstitial nephritis), systemic (e.g., anaphylaxis, drug induced hypersensitivity syndrome) or various combinations of these. Severe cutaneous adverse reactions manifesting as Stevens Johnson syndrome or toxic epidermal necrolysis (TEN) may be potentially life-threatening. The management of antibiotic allergy begins with the identification of the putative antibiotic from a detailed and accurate drug history, complemented by validated in-vivo and in-vitro allergological tests. This will facilitate avoidance of the putative antibiotic through patient education, use of drug alert cards, and electronic medical records with in-built drug allergy/adverse drug reaction prescription and dispensing checks. Knowledge of the evidence for specific antibiotic cross-reactivities is also important in patient education. Apart from withdrawal of the putative antibiotic, immunomodulatory agents like high-dose intravenous immunoglobulins may have a role in TEN. Drug desensitization where the benefits outweigh the risks, and where no alternative antibiotics can be used for various reasons, may be considered in certain situations. Allergological issues pertaining to electronic drug allergy alerts, computerized physician prescriptions and decision support systems, and antibiotic de-escalation in antimicrobial stewardship programmes are also discussed.

Patch Testing for Evaluating Drug Reactions Due to Systemic Antibiotics

Several studies have evaluated patch testing for the diagnosis of drug eruptions, but widespread acceptance of this procedure is lacking in North America. The objective of this review is to address patch testing for the evaluation of exanthematous drug eruptions due to systemic antibiotics, using a MEDLINE database search for articles in English on patch testing for systemic drug eruptions caused by antibiotics.

Clindamycin skin testing has limited diagnostic potential

We examined the role of clindamycin prick and intradermal skin testing in a tertiary care clinic population. Experience with diagnostic modalities such as prick and intradermal testing has been limited with clindamycin. A retrospective chart review was conducted for patients with immunologic reactions temporally associated with clindamycin who were referred to the Drug Safety Clinic (Toronto, Ontario). A total of 31 patients were identified who had undergone prick and intradermal skin testing. All 31 negative immediate prick and intradermal tests were followed by a 150 mg oral dose of clindamycin. 10/31 (32%) subjects had significant reactions to the oral clindamycin provocation. 2 patients reported delayed reactions at the clindamycin intradermal test sites. Our experience suggests that prick and intradermal skin testing is not adequate in identifying patients with previous allergic reactions associated with clindamycin. Oral provocation tests can be used in patients with histories of clindamycin adverse reactions; however, it should be offered on a risk-benefit basis.

The usefulness of skin tests to prove drug hypersensitivity

BACKGROUND

Suspected drug hypersensitivity is common. Only a minority of cutaneous adverse drug reactions (CADRs) are allergic in origin and will reappear after the next exposure. Methods to confirm suspected CADRs are needed and skin testing could serve as one possibility.

OBJECTIVES

To analyse the usefulness of skin tests in revealing drug allergy. The relevance of skin test results was evaluated with drug provocation studies.

METHODS

During 1989-2001, 947 patients with a history of suspected CADR were examined with skin tests including patch tests (PTs) (826 patients), skin prick tests (SPTs) (935 patients) and photopatch tests (12 patients). The occurrence of positive and negative test reactions to different drugs was correlated with clinical history. Drug provocation was carried out in 246 patients.

RESULTS

Antimicrobial drugs were suspected and tested most often. A positive PT reaction to one or more drug was seen in 89 of 826 (10.8%), most often to beta-lactams, clindamycin and trimethoprim. A positive SPT reaction was seen in 10 of 935 (1.1%) patients. Challenge was carried out in 17 patients with positive skin test results. Thirteen of 16 (81.2%) PT positives developed exanthema, three remained negative and one SPT-positive patient developed urticaria. Among skin test negatives, 207 of 229 (90.4%) challenges were negative and 22 of 229 (9.6%) were positive, 12 with exanthema, three with fixed drug eruptions and seven with urticaria.

CONCLUSIONS

Skin testing, especially the PT, was a useful screening method to find a cause of CADR if the reaction was exanthema and if antimicrobial, cardiovascular or antiepileptic drugs were suspected. The SPT detected occasional positives with antimicrobials. In cases of fixed drug eruption, PTs performed at the earlier reaction site were useful. When skin tests are negative or dubious, oral challenge should be carried out to confirm the association.

Veterinary pharmacovigilance. Part 4. Adverse reactions in humans to veterinary medicinal products

Although seemingly rare, adverse reactions to veterinary products do occur. These may arise from inadvertent exposure during use or as a result of occupational accidents. They are often mild in nature and include adverse effects such as minor skin reactions. However, more serious reactions may occur, and they are not restricted to the effects of the veterinary medicines themselves. For example, high-pressure injection injuries may occur as a result of accidents occurring during animal vaccination operations. This paper reviews some of these events, mentions where appropriate the regulatory actions taken, and describes some of the measures used to minimise such effects in the future, and serves to bring the issues discussed here to the attention of pharmacologists, pharmacoepidemiologists and others who train those who use veterinary medicinal products.