Doxycycline

Oral Antibiotics

Drug class: Tetracycline

Doxycycline (VIBRAMYCIN)（中文：多西環素）

Pronunciation

Doxycycline 100mg

Common Strengths

• 100 mg

Drug Trade Name

Vibramycin

Drug Usage

Doxycycline is a broad-spectrum antibiotic used to treat various bacterial infections, including:

• respiratory tract infections
• urinary tract infections
• Acne and rosacea
• Sexually transmitted infections (e.g. chlamydia, gonorrhea, syphilis)
• Malaria prophylaxis
• Infections caused by mites, ticks, or lice
• Anthrax treatment and prophylaxis

Mechanism of Action

Doxycycline works by inhibiting bacterial protein synthesis. It binds to the 30s ribosomal subunit of bacteria, preventing the addition of amino acids to the growing peptide chain. This action stops bacterial growth and reproduction.

Route of Administration

Doxycycline can be administered via:

• Oral (tablets or capsules)

Dosages

General Adult Dosage:

• Initial: 200 mg on the first day (may be divided into 100 mg every 12 hours)
• Maintenance: 100 mg once daily

Side Effects

Frequency	Adverse reactions
Common Side Effects	Nausea and vomiting
	Diarrhea
	Stomach pain
	Photosensitivity
Serious Side Effects	Severe allergic reactions (hives, difficulty breathing)
	Liver problems (jaundice)
	Blood disorders (low white blood cell counts)
	Esophageal irritation or ulceration

Pharmacokinetics

• Doxycycline is rapidly absorbed after oral administration.
• Onset Time: Effects can be seen within 1 to 2 hours.
• Duration of action: The half-life ranges from 15 to 30 hours.