Chlortetracycline

At Chlortetracycline it is an active substance that is used as an antibiotic in humans and animals. It helps with infectious eye diseases and wound diseases of the skin. When used in agriculture, it can enter the food chain through the consumption of grain.

What is Chlortetracycline?

Chlortetracycline (empirical formula: C22H23ClN2O8) is a crystalline solid that is yellow, odorless and only sparingly soluble in water. The antibiotic belongs to the group of tetracyclines. In Germany the agent is sold as chlortetracycline hydrochloride under the trade names Aureomycin®, Aureomycin® eye ointment (human medicine) and Animedazon® spray, Citrolan® CTC, Cyclo® spray (veterinary medicine) and in Austria as Aureocort®.

The antibiotic was discovered in 1945 by the American botanist Benjamin Duggar. The active ingredient was first isolated from the bacterium Streptomyces aureofaciens in 1948.

The antibiotic bacterium occurs in the upper soil layers and is particularly effective against staphylococci, streptococci and certain bacilli. The scientist named the drug aureomycin because of its yellowish color. Although the ending -mycin suggests a fungus, it is actually a bacterium. However, this is able to form fungal plexuses (mycelium).

In veterinary medicine, the agent is mostly used as a hydrochloride and in other dosage forms (spray, etc.) and is used to treat respiratory, urinary tract and gastrointestinal infections in various animal species. An antibiogram is usually made beforehand to check whether there is any resistance to it. Chlortetracycline used in industrial agriculture can get into the arable soil via the liquid manure and is there absorbed by the roots of the cereal plants.

Pharmacological effect

Chlortetracycline is similar in its spectrum of activity to doxycycline. It ensures that the infecting bacteria no longer produce proteins and can therefore grow. This prevents the pathogens from maturing and spreading. The substance is effective against staphylococci, streptococci, chlamydia, pneumococci, Escherichia coli and Haemophilus influenzae. It can also be applied preventively against wound infections.

In humans, the application is only external, in animals also orally (not in horses and ruminants). Chlortetracycline is only 30% bio-available when used in humans and is effective for 5 to 5 1/2 hours. It is 50 to 55% bound to plasma proteins and around 75% is metabolized in the liver. It is excreted via the urinary tract and the intestines (bile).

Medical application & use

Applied as an eye ointment, it helps with conjunctivitis, eye skin irritation, eyelid inflammation (blepharitis), corneal inflammation (keratitis) and trachoma (a chlamydial infection of the cornea that can lead to blindness if not treated in time) .

In addition, chlortetracycline is used for skin infections caused by ulcerated wounds, burns and abrasions. It helps with inflamed sebum and sweat glands (boils, abscesses), sore throat, pus lichen (impetigo) and infections of the nail bed.

Ulcus cruris ("open leg"), a lower leg ulcer, which mainly affects patients with diabetes, and decubitus ulcers can be combated extremely effectively. They often develop in bedridden patients on areas of skin that have been exposed to pressure for too long. This happens, for example, if the person concerned is not repositioned often enough. Then the capillaries of the skin are compressed so that the skin no longer receives sufficient oxygen and nutrients. If the resulting ulcer is not treated in time, it even affects tissues and muscles located far below and thus leads to necrosis (dead tissue).

For the duration of the application as an eye ointment, the patient should under no circumstances put on contact lenses. If he has forgotten to put the ointment in the conjunctival sac, he must never apply double the amount. Any excess ointment can simply be wiped off with a clean paper towel. The eye ointment is applied into the conjunctival sac in a 0.5 to 1 cm long ointment strand at the latest every 2 hours. Lighter eye infections are usually healed after 2 days. However, the patient should continue the treatment for another 3 days. In more severe cases, additional oral administration of antibiotics may be required. After applying the eye ointment, the user can only see blurred for a few minutes.

Risks & side effects

The use of chlortetracycline agents can lead to allergic reactions of the skin (contact dermatitis, skin reddening, [[rash, rashes, increased sensitivity of the skin to light, itching) and allergic mucosal reactions. If the patient develops photodermatosis when they expose their skin to UV light, they should stop treatment immediately and contact their doctor.

In children under the age of 8, the drug can rarely cause delayed bone development, underdeveloped tooth enamel and permanent tooth discoloration. In addition, long-term therapy with chlortetracycline, as with other antibiotics, can infect the patient with other bacteria and fungi and develop resistance to bacterial strains against which the active ingredient is ineffective.

Chlortetracycline should not be applied if the person concerned suffers from hypersensitivity to the active substance or other tetracyclines, if there is ocular tuberculosis, fungal infections in the area of ​​application of liver and kidney failure, lupus erythematosus and if the pathogen is changed.

Pregnant and breastfeeding women should also avoid the product, as it can lead to liver damage in the expectant mother and growth disorders in the unborn child. It also passes into breast milk. Women who take the contraceptive pill must expect the contraceptive to become less effective. Interactions with other drugs can also occur.