Products
Doxycycline is commercially available in the form of tablets, capsules, and as a solution for injection (vibramycin, vibravenous, generic). It has been approved in many countries since 1972.
Structure and properties
Doxycycline (C22H24N2O8, Mr = 444.4 g/mol) is usually present in drugs as doxycycline hyclate. Some drugs also contain doxycycline monohydrate. These are yellow crystalline powders. Doxycycline monohydrate is very slightly soluble in water, whereas doxycycline hyclate is easily soluble. Doxycycline is a derivative of oxytetracycline and has a tetracyclic structure.
Effects
Doxycycline (ATC J01AA02) has bacteriostatic properties against Gram-positive and Gram-negative pathogens. The effects are due to inhibition of bacterial protein synthesis by binding to the 30S subunit of ribosomes. The half-life ranges from 18 to 23 hours. Doxycycline exerts additional anti-inflammatory and antiparasitic effects and can be used in rosacea and malaria.
Indications
- Bacterial infectious diseases with susceptible pathogens.
- Acne vulgaris.
- Rosacea see under doxycycline for rosacea treatment.
- Malaria prophylaxis.
Dosage
According to the professional information. According to the German technical information, the tablets can be taken during or after a meal. This avoids gastrointestinal disturbances. This is also recommended in the United States. In many countries, according to the technical information, the tablets should be taken fasting, at least one hour before eating. They should be taken with sufficient liquid while sitting or standing. Do not take just before going to bed (keep at least one hour apart). If severe stomach discomfort occurs, it is also possible to take it with a meal or with a glass of milk, but in this case the absorption is reduced (about 20%). During treatment, strong sun or UV radiation should be avoided, because the drug can make the skin more sensitive to sun.
Contraindications
- Hypersensitivity
- Severe liver dysfunction
- Pregnancy
Full precautions can be found in the drug label.
Interactions
Other drugs may reduce absorption. These include antacids, iron supplements, certain minerals and trace elements, activated charcoal, and cholestyramine. If such medications are taken, a time interval must be observed. Other interactions may occur (see FI).
Adverse effects
Common to occasional possible adverse effects include nausea, blood clotting disorders, blood in the urine, vomiting, diarrhea, inflammation of the tongue, inflammation of the mouth and throat, hoarseness, difficulty swallowing, black hair tongue, pruritus, skin rash, photosensitivity, and headache.
