– Chlortetracycline Hydrochloride is a tetracycline with broad-spectrum antibacterial and antiprotozoal activity. Chlortetracycline hydrochloride (Isphamycin) is bacteriostatic and inhibits bacterial protein synthesis by binding to the 30S ribosomal subunit, thereby preventing the addition of amino acids to the growing peptide chain. This tetracycline is active against a wide range of gram-positive and gram-negative organisms, spirochetes, rickettsial species, certain protozoa and Mycoplasma and Chlamydia organisms.