| drug name | Doxycycline |
| classification | Tetracycline antibiotic |
| pharmacokinetics | | absorption | Well absorbed from the gastrointestinal tract, but absorption is reduced by food, antacids, and calcium supplements. Bioavailability is around 75%. | | distribution | Distributed throughout the body, including the tissues and fluids. Concentrations vary in different tissues. | | metabolism | Metabolized in the liver, primarily by the cytochrome P450 system. Excreted primarily in the urine. | | elimination | Elimination half-life is approximately 16-22 hours, but can be prolonged in renal impairment. Excreted in urine and bile. |
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| suggested dosage | | adult general | Typical dose is 100-200mg per day in divided doses, adjusted based on the specific infection and severity. For severe infections or specific conditions, dosage may be higher. | | weight specific | The dosage above is a guideline. Specific dosage and duration should be determined by a healthcare professional based on individual patient factors, including the severity of the infection, the patient's kidney function, and other relevant conditions. | | special instructions | Take with a full glass of water. Avoid taking with milk, dairy products, or antacids. |
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| indications | | 1 | Bacterial infections of various sites, including skin infections, respiratory infections, sexually transmitted infections (STIs) such as chlamydia and gonorrhea, Lyme disease, and some types of rickettsial infections (e.g., Rocky Mountain spotted fever). | | 2 | Acne treatment |
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| safety pregnancy | Doxycycline should be used with caution during pregnancy, as it may cross the placenta and affect fetal development. Consult a physician before use if pregnant or planning pregnancy. |
| safety breastfeeding | Doxycycline may be present in breast milk. It is best to discontinue breastfeeding or avoid use during breastfeeding in women planning or currently breastfeeding. |
| side effects | | 1 | Gastrointestinal upset (nausea, vomiting, diarrhea, abdominal pain) | | 2 | Headache, dizziness | | 3 | Photosensitivity (increased skin sensitivity to sunlight). | | 4 | Vaginal candidiasis | | 5 | Changes in taste | | 6 | Superinfection | | 7 | Liver problems | | 8 | Renal impairment | | 9 | Dermatitis |
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| alternatives | |
| contraindications | | 1 | Known hypersensitivity to tetracyclines | | 2 | Severe liver disease | | 3 | Severe renal disease | | 4 | Pregnancy (unless benefit outweighs risk – consult a physician) | | 5 | Lactation (unless benefit outweighs risk – consult a physician) |
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| interactions | | 1 | Antacids and calcium-containing products reduce absorption. | | 2 | Certain medications that affect the cytochrome P450 system. | | 3 | Oral anticoagulants | | 4 | Digoxin |
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| warnings precautions | | 1 | Patients with renal impairment should have their dosage adjusted appropriately. | | 2 | Patients with history of liver disease should be monitored. | | 3 | Photosensitivity reactions can occur, especially with prolonged sun exposure. | | 4 | Avoid use in young children (children under 8 years of age) unless benefit outweighs risk. Consult a pediatrician | | 5 | Monitor for signs of superinfection (e.g., oral thrush). | | 6 | Can cause tooth discoloration and affect bone development in growing children. |
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| additional information | | administration | Take with a full glass of water on an empty stomach for optimal absorption. Avoid taking with milk products or calcium supplements. | | storage | Store at room temperature away from moisture and sunlight. | | important notes | Consult a physician for diagnosis and treatment of infections. Adhere to the prescribed course of treatment. |
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