Is Cephalexin (Cefalexin) effective for treating sinusitis?

From the Guidelines

Cephalexin is not the preferred antibiotic for treating sinus infections due to its poor coverage of common bacterial pathogens, such as Haemophilus influenzae and Moraxella catarrhalis, as noted in the study published in the Journal of Allergy and Clinical Immunology 1.

Key Points to Consider

• Most sinus infections are viral and do not require antibiotics, as stated in the Annals of Internal Medicine study 1.
• Bacterial sinus infections typically persist for more than 10 days, worsen after initial improvement, or present with severe symptoms like high fever and facial pain.
• The American Academy of Otolaryngology-Head and Neck Surgery emphasizes watchful waiting (without antibiotic therapy) as initial management for all patients with uncomplicated acute bacterial rhinosinusitis (ABRS), regardless of severity 1.
• Amoxicillin-clavulanate is the preferred agent for treating ABRS, and doxycycline or a respiratory fluoroquinolone may be used as an alternative in patients with ABRS, as recommended by the Infectious Diseases Society of America (IDSA) 1.

Treatment Approach

• Reserve antibiotic treatment for acute rhinosinusitis for patients with persistent symptoms for more than 10 days, onset of severe symptoms or signs of high fever (>39 °C) and purulent nasal discharge or facial pain lasting for at least 3 consecutive days, or onset of worsening symptoms following a typical viral illness that lasted 5 days that was initially improving (double sickening) 1.
• Consider adjunctive therapy, such as intranasal saline irrigation or intranasal corticosteroids, to alleviate symptoms and potentially decrease antibiotic use 1.

Patient Management

• Most patients with acute rhinosinusitis should be managed with supportive care, including analgesics for pain and antipyretics for fever, as well as additional therapies tailored to the patient's symptoms, such as systemic or topical decongestants, saline nasal irrigation, mucolytics, intranasal corticosteroids, and antihistamines 1.

From the Research

Cephalexin for Sinus Infection

• Cephalexin is an antibiotic that can be used to treat sinus infections, as shown in a study from 1985 2.
• The study found that cephalexin was effective in treating sinusitis, with satisfactory clinical results in 83% of patients.
• However, other studies have compared the effectiveness of different antibiotics for sinus infections, including amoxicillin, amoxicillin-clavulanate, and cephalosporins 3, 4, 5.
• These studies found that amoxicillin and amoxicillin-clavulanate were effective in treating sinus infections, but that cephalosporins, such as cephalexin, may have fewer adverse effects 3, 4.
• A study from 2021 found that amoxicillin was a viable option for adults with acute sinusitis, with similar efficacy to amoxicillin-clavulanate and fewer gastrointestinal-related adverse events 5.
• The choice of antibiotic for sinus infection should be based on the severity of the infection, the patient's medical history, and the potential for adverse effects, as well as the results of diagnostic tests, such as imaging or bacterial culture 6, 2, 3, 4.

Alternatives to Cephalexin

• Other antibiotics that can be used to treat sinus infections include:
  • Amoxicillin
  • Amoxicillin-clavulanate
  • Cefuroxime
  • Cefpodoxime
  • Cefdinir
  • Clarithromycin
  • Azithromycin
• The choice of antibiotic should be based on the patient's medical history, the severity of the infection, and the potential for adverse effects 6, 3, 4, 5.

Duration of Therapy

• The optimal duration of therapy for sinus infections is unknown, but most studies recommend treatment for 7-14 days 6, 3, 4.
• Some studies have found that longer durations of therapy may be necessary for more severe infections or for patients with underlying medical conditions 6, 3, 4.