Cephalexin is a commonly prescribed antibiotic in Australia, used to treat a variety of bacterial infections. While it is generally safe and effective, there are important warnings and precautions that users should be aware of to ensure safe use and to minimize risks. This blog post outlines key warnings related to cephalexin based on Australian health guidelines and product information.
Allergic Reactions and Contraindications
One of the most critical warnings for cephalexin is the risk of allergic reactions. Cephalexin belongs to the cephalosporin class of antibiotics, and people who have had previous allergic reactions to cephalexin, other cephalosporins, or penicillin should avoid using it. Allergic symptoms can include:
- Swelling of the face, lips, tongue, or throat
- Difficulty breathing, wheezing, or shortness of breath
- Rash, itching, or hives on the skin
If you experience any of these symptoms, stop taking cephalexin immediately and seek emergency medical attention.
Use with Caution in Certain Populations
- Pregnancy and Breastfeeding: Cephalexin is classified as a Category A drug by the Australian Therapeutic Goods Administration (TGA), indicating it is generally considered safe during pregnancy. However, it should only be used when clearly needed and under medical supervision. It is excreted in breast milk, so caution is advised during breastfeeding.
- Kidney Impairment: Dosage adjustments may be necessary for patients with reduced kidney function to avoid accumulation and toxicity.
- History of Severe Allergies: Patients with a history of serious allergic reactions to antibiotics should inform their healthcare providers before starting cephalexin.
Common and Serious Side Effects
Most side effects of cephalexin are mild and include nausea, vomiting, diarrhea, headache, dizziness, and tiredness. Oral or vaginal thrush (yeast infections) may also occur due to disruption of normal flora.
More serious side effects, although rare, require urgent medical attention:
- Severe allergic reactions (anaphylaxis)
- Severe diarrhea, especially if watery or bloody, which may indicate Clostridium difficile-associated diarrhea or colitis. This can occur during or weeks after treatment. Do not take anti-diarrheal medications without consulting a doctor.
- Signs of liver problems such as yellowing of the skin or eyes
- Unusual bleeding or bruising
- Severe skin reactions such as rash, blistering, or peeling
If you notice any serious side effects, contact your doctor immediately or go to the nearest emergency department.
Overdose and What to Do
Taking more than the prescribed dose of cephalexin can lead to symptoms such as nausea, diarrhea, blood in urine, convulsions, or hallucinations. In case of suspected overdose, contact the Australian Poisons Information Centre on 13 11 26 or seek emergency medical care right away, even if no symptoms are present.
Important Usage Warnings
- Do not use cephalexin if the packaging is damaged or past its expiry date.
- Always inform your healthcare provider about all other medications you are taking to avoid potential drug interactions.
- Complete the full prescribed course, even if you start feeling better before finishing the medication.
- If you experience severe diarrhea or signs of thrush (white patches in the mouth or vaginal itching), inform your doctor promptly.
Summary
Cephalexin is a valuable antibiotic widely used in Australia, but it comes with important warnings to ensure safe and effective use. Allergic reactions, serious gastrointestinal side effects, and proper dosing adjustments are key considerations. Always follow your healthcare provider’s instructions, report any unusual symptoms promptly, and seek emergency care if severe side effects occur.