Sykliineja

Sykliineja (tetracyclines) are a class of broad-spectrum antibiotics used in human and veterinary medicine. They inhibit bacterial protein synthesis by reversibly binding to the 30S ribosomal subunit, blocking the attachment of aminoacyl-tRNA and thereby preventing translation. The effect is generally bacteriostatic.

Common members include tetracycline, doxycycline, minocycline and oxytetracycline. Doxycycline is notable for good oral bioavailability and a long half-life, which allows once-daily dosing. Sykliineja have a wide spectrum, covering many Gram-positive and Gram-negative bacteria as well as atypical pathogens such as Mycoplasma, Chlamydia and Rickettsia. They are used for respiratory tract infections, skin and soft tissue infections (including acne), sexually transmitted infections such as chlamydia, and tick-borne diseases like Lyme disease and Rocky Mountain spotted fever, as well as malaria chemoprophylaxis in travelers.

Pharmacokinetics and safety: absorption is reduced when taken with dairy products or supplements containing calcium, iron, magnesium, or aluminum, so dosing should be separated from these substances. Doxycycline and minocycline generally have good oral bioavailability; tetracycline is more susceptible to interactions. Sykliineja can accumulate in bone and teeth, and are typically avoided during pregnancy and in children under eight due to risks of tooth discoloration and enamel defects. Photosensitivity is another possible adverse effect; other common side effects include gastrointestinal upset and, less commonly, liver or kidney issues.

Resistance and stewardship: resistance mechanisms include efflux pumps and ribosomal protection proteins; resistance genes can spread among bacteria, reducing effectiveness and underscoring the importance of prudent use.