From the Guidelines
Cephalexin has a higher risk of toxic epidermal necrolysis (TEN) compared to Terbinafine. As a beta-lactam antibiotic, cephalexin belongs to a class of medications that carries a higher risk of severe cutaneous adverse reactions (SCARs) including TEN and Stevens-Johnson Syndrome (SJS) 1. Beta-lactam antibiotics are among the most common causes of drug-induced TEN, while terbinafine, an antifungal medication, has been associated with these reactions less frequently, with an incidence of serious adverse events of 0.04% 1. Some key points to consider when prescribing these medications include:
- The risk of TEN with cephalexin typically emerges within the first 8 weeks of treatment, with most cases occurring within the first 14 days.
- Patients with a history of severe cutaneous reactions to either medication should avoid that drug in the future, and this information should be prominently documented in their medical records as a severe allergy.
- If a patient develops symptoms such as skin pain, mucosal involvement, blistering, or a spreading rash while taking either medication, they should seek immediate medical attention and discontinue the drug. It's also important to note that while terbinafine has been associated with rare reports of serious adverse reactions, including Stevens–Johnson syndrome and toxic epidermal necrolysis, the overall risk is lower compared to cephalexin 1. Therefore, when considering the risk of toxic epidermal necrolysis, Terbinafine is a safer option compared to Cephalexin.
From the Research
Comparison of Cephalexin and Terbinafine
- Cephalexin is a beta-lactam antibiotic, and according to 2, beta-lactam antibiotics are among the drugs most commonly involved in Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN).
- Terbinafine is an antifungal medication, and there is no direct mention of it being a common cause of SJS/TEN in the provided studies.
- However, it is essential to note that any drug can potentially cause SJS/TEN, and the risk may vary depending on individual factors and genetic predispositions, as discussed in 3 and 4.
- A study on the specific risk of SJS/TEN associated with Cephalexin and Terbinafine is not provided, but based on the available information, beta-lactam antibiotics like Cephalexin may have a higher reported association with SJS/TEN compared to Terbinafine.
Drug-Induced SJS/TEN
- The provided studies 2, 4, 5 suggest that certain medications, including antibiotics, anticonvulsants, and non-steroidal anti-inflammatory drugs, are more commonly associated with SJS/TEN.
- Early recognition and prompt withdrawal of the causative agent are crucial for improving patient survival, as highlighted in 5.
- It is also important to consider the patient's medical history, including any previous adverse reactions to medications, as noted in 5.