SHEET /vs/doxycycline-vs-azithromycin · COMPARISON
Doxycycline vs Azithromycin: what is the difference?
How they differ
from source
Both stop bacteria making protein and they bind different parts of the ribosome. Doxycycline is a tetracycline and blocks the 30S subunit; azithromycin is a macrolide and blocks the 50S. Both penetrate tissue well and both cover the atypical organisms that cell-wall antibiotics miss, which is why they overlap in respiratory and sexually transmitted infections. Doxycycline causes photosensitivity and stains developing teeth, which is why it is avoided in young children, and azithromycin does not. Azithromycin is the much larger molecule at 749.0 against 444.4, and its very long tissue half-life is why courses are short.
Side by side
| Doxycycline | Azithromycin | |
|---|---|---|
| Formula | C22H24N2O8 | C38H72N2O12 |
| Molecular weight | 444.4 g/mol | 749 g/mol |
| Family | Antibiotics | Antibiotics |
| Everyday group | Prescription medicine | Prescription medicine |
| Functional groups | Alcohols, Aromatics, Ketones, Amides, Phenols | Alcohols, Esters, Ethers |
| GHS signal wordThe supplier-filed hazard label, not a statement about ordinary use. | not recorded | Danger |
| CAS number | 7164-70-7 | 83905-01-5 |
| PubChem CID | 54671203 | 447043 |
Common questions
- What is the difference between Doxycycline and Azithromycin?
- Both stop bacteria making protein and they bind different parts of the ribosome. Doxycycline is a tetracycline and blocks the 30S subunit; azithromycin is a macrolide and blocks the 50S. Both penetrate tissue well and both cover the atypical organisms that cell-wall antibiotics miss, which is why they overlap in respiratory and sexually transmitted infections.
- Is Doxycycline bigger than Azithromycin?
- Azithromycin is the heavier molecule, 749 g/mol against 444.4 g/mol for Doxycycline. Doxycycline is C22H24N2O8 and Azithromycin is C38H72N2O12.
Read the full records: Doxycycline and Azithromycin.