Tetracycline Dosage and Treatment Plan for Bacterial Infections
For bacterial infections, the recommended dosage of doxycycline is 200 mg on the first day (administered as 100 mg every 12 hours), followed by a maintenance dose of 100 mg/day for most infections, with treatment duration typically ranging from 7-14 days depending on the specific infection. 1
Standard Dosing for Adults
- For most bacterial infections in adults, doxycycline is administered at 100 mg twice daily on day 1, followed by 100 mg once or twice daily depending on infection severity 1
- For more severe infections (particularly chronic urinary tract infections), 100 mg every 12 hours is recommended throughout the treatment course 1
- Administration with food or milk is recommended if gastric irritation occurs, although absorption is not markedly influenced by simultaneous food intake 1
Specific Infection Dosing Guidelines
Sexually Transmitted Infections
- Uncomplicated gonococcal infections: 100 mg twice daily for 7 days 1
- Alternative single-visit dose: 300 mg followed by another 300 mg one hour later 1
- Chlamydia infections (urethral, endocervical, or rectal): 100 mg twice daily for 7 days 1
- Nongonococcal urethritis: 100 mg twice daily for 7 days 1
Syphilis
- Early syphilis in penicillin-allergic patients: 100 mg twice daily for 2 weeks 1
- Syphilis of more than one year's duration: 100 mg twice daily for 4 weeks 1
Skin and Soft Tissue Infections
- For MRSA skin and soft tissue infections: doxycycline or minocycline are recommended oral options 2
- Standard dosing of 100 mg twice daily is typically used 2
- Treatment duration of 7-14 days is recommended, individualized based on clinical response 2
Minocycline Dosing
- Minocycline is typically started with a loading dose of 200 mg followed by 100 mg twice daily 2
- Particularly effective for MRSA colonization/infection compared to other tetracyclines 3
Special Considerations
Pediatric Dosing
- For children over 8 years of age weighing less than 100 pounds: 2 mg/lb of body weight divided into two doses on the first day, followed by 1 mg/lb daily as a single dose or divided into two doses 1
- For more severe infections: up to 2 mg/kg may be used 1
- For children over 100 pounds: use adult dosing 1
- Tetracyclines are generally not recommended for children under 8 years of age due to potential effects on developing teeth and bones 2
Renal Impairment
- Doxycycline does not require dose adjustment in patients with renal impairment 3
- This is an advantage over some other antibiotics that require significant dosing adjustments in renal dysfunction 3
Administration Guidelines
- Adequate fluid intake is recommended with capsule and tablet forms to reduce the risk of esophageal irritation and ulceration 1
- Take doxycycline on a full stomach with a full glass of liquid 2
- Avoid lying down for 1 hour after taking doxycycline to prevent esophagitis 2
- The therapeutic antibacterial serum activity typically persists for 24 hours following the recommended dosage 1
Duration of Therapy
- For most common bacterial infections: 7-14 days 2
- For streptococcal infections: therapy should be continued for 10 days 1
- For specific infections like syphilis: 2-4 weeks depending on disease duration 1
- For prophylactic use (such as malaria): daily dosing beginning 1-2 days before travel and continuing for 4 weeks after leaving the malarious area 1
Common Adverse Effects
- Photosensitivity (increased sensitivity to sunlight) 2
- Gastrointestinal symptoms including nausea, vomiting, and diarrhea 2
- Esophageal erosion and ulceration (can be minimized with proper administration) 2
- Most adverse effects resolve with discontinuation of the medication 2
Advantages of Doxycycline
- Long half-life (approximately 12 hours) allowing for convenient twice-daily dosing 2
- Well absorbed orally even with food 3
- Excellent tissue penetration 3
- No dose adjustment required in renal insufficiency 3
Remember that tetracyclines are bacteriostatic antibiotics that act by binding to the bacterial 30S ribosomal subunit and inhibiting protein synthesis 4. They exhibit broad-spectrum activity against numerous pathogens, including Gram-positive and Gram-negative bacteria, as well as atypical organisms 4.