Cephalexin vs Amoxicillin: Beating Bacterial Infections

Bacterial infections have become extremely common recently since more and more people are becoming prone to them. To treat such infections, the most efficient cure is antibiotics. These are the medicines that kill the bacteria that are the root of any infectious disease and enhance the immunity of the body. Antibiotics are also used for the treatment of bacterial infections and are known as antibacterial medicines. One of the first of this kind was Penicillin. It has been used for ages to cure numerous diseases. Many more antibiotics were developed after Penicillin and some of them are even more effective than it. Two such antibiotics that are nowadays used all over the world to treat bacterial infections of different kinds are Cephalexin and Amoxicillin. Both of these are prescribed by the doctors to treat bacterial diseases.

If you are someone who is currently taking any one of these medicines and want to know the difference between Cephalexin and Amoxicillin, this article can help you. Here we will give all the information that you need to know regarding Cephalexin and Amoxicillin and the differences between them.

What are Amoxicillin and Cephalexin?

Cephalexin and Amoxicillin are the two drugs that are commonly prescribed to the patients who are suffering from bacterial infections. Both of these are prescription medicines and are not sold to the patients over-the-counter. These are broad-spectrum antibiotics what means that they can target a wide range of bacteria. Some of the most common diseases treated by these antibiotics are skin infections, sinusitis, otitis media, bone infections, uncomplicated pneumonia. Although these two drugs have their own uses in the body, they are often used in each other's place in medical practice.

Side effects of Cephalexin and Amoxicillin

Each medicine has its own side effects, which are usually caused by an overdose or by taking the medicine in a wrong way. Also, adverse effects may be the result of the patient being allergic to the medication. Although the composition of Cephalexin and Amoxicillin is different, both of these can cause allergies in the patients. What's more, if a person is allergic to Penicillin, he/she will be allergic to both of these medicines as well. The side effects caused by Cephalexin and Amoxicillin range from mild to severe. Here are some of the most common side effects:

  • Diarrhea: One of the most common side effects of both these medicines is diarrhea. It goes away in a week. However, if diarrhea gets more serious, it is better to consult with your doctor since it can get deadly.
  • Abdominal pain: Abdominal pain is another thing that can be observed in the patients who are given any one of the two drugs. Usually people have abdominal bloating and cramps for a few days after they start taking Amoxicillin or Cephalexin.
  • Nausea and vomiting: Another side effect of taking the medicine in a wrong way or overdosing is that the person feels nauseous and also sometimes vomits. If vomiting continues, the patient should be immediately taken to the hospital.
  • Dizziness: Dizziness, loss of balance, and confusion are the three symptoms that might be seen in the patients treated by Amoxicillin or Cephalexin. Although these effect usually last for a short period of time, they should not be taken lightly.
  • Skin allergies and rashes: Skin allergies and rashes are the symptoms of allergic reactions to the medicines. The skin on the face and hands turns red and starts to itch. You might also experience swelling of the lips and other areas. Skin allergies can develop into a severe form, and therefore should be dealt with immediately.
  • Seizures: Although seizures happen only in extreme cases of allergies to the medicine, it is still important to get checked by the doctor before taking these medicines.

However, it is important to note that not all people suffer from these side effects. And even when they occur, they are easily treatable.

Differences between Cephalexin and Amoxicillin

Both Cephalexin and Amoxicillin are used to treat bacterial infections. However, these two differ in many ways. Some of the major differences between these are:

  • Composition: Amoxicillin is a derivative of Penicillin and has a structure similar to it. Cephalexin, on the other hand, is a derivative of Cephalosporin. Both of these classes of antibiotics are similar in some ways but different in the others.
  • Form: Amoxicillin is more easily accessible and comes in many more forms in the market, such as chewable tablets, delayed-release tablets, and many more. Cephalexin, on the other hand, is only available in the three basic forms including capsules, tablets, and oral suspension.
  • Diseases treated: Both Cephalexin and Amoxicillin are used to treat some similar diseases but some diseases they treat are completely different from one another. Cephalexin is used to treat diseases, such as bone infection, cystitis, and acute prostatitis. Amoxicillin can be used to treat uncomplicated pneumonia, sinusitis, duodenal ulcer disease, and much more.
  • Half-life: The medicine's half-life is a measure of how long the drug acts in the body and shows its effects. The half-life of Cephalexin is 0.6-1.2 hours which means that the medicine acts in the body for almost 2-2.5 hours. The half-life of the immediate-release formula of Amoxicillin is 1 hour which means it can show its effects in the body for 2 hours. The half-life for the extended-release formula is 90 minutes which means it can last for about 3 hours.
  • Prescription: Both Amoxicillin and Cephalexin are prescription medicines. It is advised to take Amoxicillin with or just after eating food. This is not the case with Cephalexin, which can be taken without regard to meals.
  • Drug interaction: Amoxicillin rarely interacts with any kind of drug and shows slowed performance rates. Cephalexin, on the other hand, may reduce the effectiveness of typhoid vaccines and BCG.
  • Breastfeeding: Amoxicillin is not harmful for the breastfeeding women. However, Cephalexin is not prescribed during the breastfeeding period as is may be toxic.
  • Price: The price of Cephalexin is at least 40% higher than that of Amoxicillin. Both of these are available in branded and generic forms.


Cephalexin and Amoxicillin are efficient antibiotics that are extremely helpful in getting rid of bacterial infections. However, there are some differences that might make one more suitable for you than the other. Hence, make sure to consult your doctor before using any of these medicines.