What is Cefdinir?
Cefdinir is a third-generation cephalosporin antibiotic used to treat a wide range of mild-to-moderate bacterial infections [1.6.3, 1.6.6]. It works by killing bacteria or preventing their growth [1.6.2]. Healthcare providers commonly prescribe it for conditions such as pneumonia, bronchitis, ear infections, sinusitis, and certain skin infections [1.6.1, 1.6.5]. It is available as an oral capsule and a powder for suspension [1.6.3]. Cefdinir is effective against many common bacteria but will not work for viral infections like the common cold or flu [1.6.1].
Common and Serious Side Effects
Like all medications, cefdinir can cause side effects. The most commonly reported side effect is diarrhea [1.5.3]. Other common side effects include nausea, vomiting, headache, and vaginal itching or discharge [1.2.3, 1.5.2].
While most side effects are mild, cefdinir can also cause serious reactions that require immediate medical attention. These include severe, watery, or bloody diarrhea (which can occur months after the last dose), severe skin reactions with blistering and peeling, signs of an allergic reaction like hives and swelling, and kidney problems [1.2.3, 1.5.2]. Fever is listed as a serious or rare side effect that should be reported to a doctor promptly [1.2.2, 1.5.1].
The Phenomenon of Drug-Induced Fever
Drug-induced fever is defined as a fever that coincides with the administration of a drug and has no other explanation [1.8.2]. The fever typically resolves within 48 to 72 hours after the offending drug is discontinued [1.8.6, 1.8.1]. Antimicrobials, such as beta-lactams (the class that includes cephalosporins like cefdinir), are among the most common drug classes associated with drug fever [1.4.7].
The exact mechanism is often related to a hypersensitivity or immune-mediated response to the drug [1.7.5]. It can occur days or even weeks after starting the medication [1.4.5, 1.5.4]. A key challenge is that it's a diagnosis of exclusion, meaning other potential causes of fever, especially the underlying infection, must be ruled out [1.8.3, 1.8.5].
Differentiating Infection Fever from Drug-Induced Fever
A key challenge for clinicians is distinguishing between a fever caused by the original infection and one caused by the medication meant to treat it. Several clues can help:
- Timing: A drug-induced fever often appears 7 to 10 days after starting a new medication [1.8.6].
- Patient's Condition: If the patient's other symptoms are improving but a new fever develops, drug fever is a possibility [1.8.1].
- Associated Symptoms: Drug fever may be accompanied by a rash, but not always [1.8.3]. A classic sign, though not always present, is relative bradycardia, where the heart rate doesn't increase as much as expected for the degree of fever [1.8.4].
- Resolution: The definitive test is stopping the suspected medication. If the fever resolves within 72 hours, it was likely drug-induced [1.8.1].
Can Cefdinir Cause Fever?
Yes, cefdinir can cause fever [1.2.3, 1.5.1]. It is listed as a rare or serious side effect across multiple medical resources [1.3.3, 1.5.6]. Often, the fever is part of a larger systemic reaction, such as a severe skin reaction or an allergic response, and may be accompanied by chills, body aches, and flu-like symptoms [1.2.3]. Cleveland Clinic specifically advises patients to contact their care team right away if they notice fevers or flu-like symptoms along with a rash while taking cefdinir [1.5.4].
Fever can also be a symptom of a more severe, though rare, complication associated with many antibiotics, including cefdinir: Clostridioides difficile (C. diff) infection. This condition causes severe, watery, or bloody diarrhea and stomach cramps, and can occur during or even months after antibiotic treatment [1.2.3, 1.3.1].
Antibiotic Side Effect Comparison
Different antibiotics have varying side effect profiles. Here is a general comparison:
| Feature | Cefdinir (Cephalosporin) | Amoxicillin (Penicillin) | Azithromycin (Macrolide) |
|---|---|---|---|
| Common Side Effects | Diarrhea, nausea, headache, vaginal yeast infections [1.5.3] | Diarrhea, nausea, rash, vomiting | Diarrhea, nausea, abdominal pain, vomiting |
| Fever as Side Effect | Listed as a rare or serious side effect, often with other symptoms like rash or allergic reaction [1.5.1, 1.2.3] | Can occur, often as part of an allergic reaction | Less commonly reported but can occur |
| Risk of C. diff | Yes, risk is present with most antibiotics [1.3.6] | Yes, risk is present | Yes, risk is present |
What to Do If You Develop a Fever
If you develop a fever while taking cefdinir, it is crucial to contact your doctor immediately [1.2.3, 1.5.2]. Do not assume it is a normal part of the illness or a minor side effect. Your doctor needs to evaluate the situation to determine if the fever is from the original infection not responding to treatment, a new secondary infection, a severe allergic reaction, or a direct drug-induced fever.
Management involves identifying and stopping the causative agent [1.7.2]. If drug fever is confirmed, it should resolve after discontinuing cefdinir [1.8.6]. Your doctor will advise on an alternative antibiotic if treatment is still necessary. Never stop taking an antibiotic without consulting your healthcare provider [1.6.1].
Conclusion
While cefdinir is a well-tolerated and effective antibiotic for many bacterial infections, it carries the potential for side effects, including the rare but serious occurrence of fever [1.5.1]. This can manifest as a direct drug-induced fever—a hypersensitivity reaction—or as a symptom of a more severe complication like C. diff-associated diarrhea or a systemic allergic reaction [1.2.3, 1.3.6]. Due to these possibilities, any fever that develops during or after a course of cefdinir warrants immediate consultation with a healthcare professional to ensure proper diagnosis and safe management.
For more information on this medication, you can visit the MedlinePlus page on Cefdinir.
