Treatment for bacterial infections include the use of penicillin class of antibiotics that is one of the first to have been successfully used as treatment. However, due to apprehensions of reactions or allergies individuals seeking treatment with antibiotics often have doubts about medications. For instance, this is a common question faced by treating specialists – – is Zithromax a penicillin? Following sub sections offer a detailed look at these antibiotics to clear apprehensions about the drugs, helping patients seek and receive the right treatment.
What is penicillin and what is the mechanism of action?
Penicillin is a group of antibiotics derived from the mold Penicillium, and are among the first drugs to be used against bacterial infections. One of the most widely used groups of antibiotics, penicillin antibiotics are used to treat a wide range of infections, including pneumonia, strep throat, skin infections, and urinary tract infections.
The mechanism of action of penicillin is its ability to inhibit the synthesis of the bacterial cell wall. They bind to and inactivate enzymes called transpeptidases, responsible for cross-linking the peptidoglycan molecules that make up the cell wall. This disrupts the structural integrity of the cell wall, causing the bacteria to lose its shape and ultimately leading to cell death. Penicillin does not affect the cell membrane, thereby not causing any damage to host cells. Of late, penicillin resistance has developed in certain bacterial species, – Staphylococcus aureus (MRSA) and Streptococcus pneumoniae. New types of penicillin/antibiotics are presently being developed to overcome this resistance.
Conditions that are typically treated with penicillin
Common treated infections include respiratory tract infections, skin infections, strep throat, urinary tract infections, syphilis, and gonorrhea. Penicillin is not effective against viral infections such as the common cold or flu, and are only to be used to treat bacterial infections as prescribed by treating specialists.
Is Zithromax a penicillin?
With the background information about penicillin, it is time to answer the question. The straight, short answer is – No, Zithromax is not a penicillin antibiotic, but a macrolide antibiotic. It is used to treat a wide range of bacterial infections, including respiratory tract infections, skin infections, and sexually transmitted infections. Individuals allergic to penicillin may not be allergic to azithromycin or other antibiotics. However, individuals with known allergy to macrolides, are not to take azithromycin.
What is a macrolide antibiotic and what is the mechanism of action?
Macrolide antibiotics are a class of antibiotics derived from a type of soil fungus called Streptomyces. Drugs such as azithromycin (Zithromax), erythromycin, and clarithromycin (Biaxin), belong to this category, and are used to treat a wide range of bacterial infections including gastrointestinal infections.
The mechanism of action of macrolide antibiotics is inhibition of bacterial protein synthesis. Macrolides bind to the 50S ribosomal subunit of the bacteria, preventing the formation of peptide bonds between amino acids, thereby inhibiting the formation of new proteins and preventing the bacteria from growing and reproducing. Macrolide antibiotics have a similar mechanism of action as the Lincosamide and streptogramin B antibiotics. They differ from one another by the chemical structure of their macrocyclic lactone ring which gives them different properties such as spectrum of activity, pharmacokinetics and resistance patterns.
Macrolide resistance has also developed among specific bacterial species, particularly Streptococcus pneumoniae and Mycoplasma pneumoniae. New macrolides are in various stages of research and development to overcome this resistance.
Conditions treated by macrolide antibiotics
While some of the infections treated by penicillin antibiotics and macrolide antibiotics may be the same, there are differences in other infections that can be treated. Commonly treated infections include the following:
#1 Respiratory tract infections: Pneumonia, bronchitis, and sinusitis caused by bacteria such as Haemophilus influenzae, Streptococcus pneumoniae, and Mycoplasma pneumoniae.
#2 Skin and soft tissue infections: Impetigo, cellulitis, and erysipelas.
#3 Ear, nose and throat infections: Otitis media, pharyngitis and tonsillitis caused by bacteria such as Streptococcus pyogenes.
#4 Genital and urinary tract infections: Urethritis, cervicitis and pelvic inflammatory disease caused by bacteria such as Chlamydia trachomatis and Neisseria gonorrhoeae.
#5 Gastrointestinal tract infections: Campylobacter enteritis and Helicobacter pylori infections.
Macrolides are not effective against all types of bacteria, and may not be effective against gram-negative bacteria and anaerobic bacteria. Additionally, macrolides are not to be used as a first-line treatment for serious infections such as meningitis, sepsis, or endocarditis, as they are not as active against the bacteria that typically cause these infections.
What are the main differences between penicillin and macrolide antibiotics
The main difference between penicillin and macrolide antibiotics is their mechanism of action and the types of bacteria they are effective against.
- Mechanism of action: There are differences in the manner in which both the drugs work, as outlined separately, and in detail above.
- Spectrum of activity: Penicillins are primarily effective against gram-positive bacteria, such as Staphylococcus, Streptococcus and Enterococcus. Macrolides, in general, have a broader spectrum of activity that includes Haemophilus influenzae, Streptococcus pneumoniae, Mycoplasma pneumoniae, Chlamydia trachomatis, and Neisseria gonorrhoeae.
- Resistance: Penicillin resistance is a growing concern among certain bacterial species, particularly Staphylococcus aureus (MRSA) and Streptococcus pneumoniae. Macrolide resistance is also a growing concern among certain bacterial species, particularly Streptococcus pneumoniae and Mycoplasma pneumoniae.
- Other properties: Penicillins are usually less expensive and have a long history of safe use, macrolides tend to have fewer side effects and are better tolerated, they are also active against atypical pathogens such as Mycoplasma, Chlamydia, Legionella, and some strains of Streptococcus pneumoniae.
How are antibiotics administered?
Antibiotics are generally administered in one of three different forms – oral formulations, topical applications and injections. The oral formulations are tablets, capsules, and liquids, for moderate infections. The topical applications are intended for treating skin infections. The injections are used as treatment for serious infections, and may be administered either in the muscle or the blood. Mid infections are generally not treated using antibiotics, as the body’s immune system is likely to overcome the infection without medication. The choice of antibiotic depends on the type of infection and its causative organism, and this is determined by a healthcare professional based on various tests and diagnosis, including culture and sensitivity test results.