Doxycycline Monohydrate Is Not Available in a Delayed-Release Formulation
No, doxycycline monohydrate is not available in a delayed-release formulation. According to the British Thoracic Society guidelines, only doxycycline hyclate is available in a modified-release formulation 1.
Available Doxycycline Formulations
Doxycycline Monohydrate
- Standard immediate-release formulation only
- Available as capsules and tablets
Doxycycline Hyclate
- Available in both immediate-release and delayed-release formulations
- The delayed-release formulation includes:
- 40 mg modified-release capsules (specifically noted as "not recommended for use in NTM infections") 1
- Doryx (doxycycline hyclate delayed-release 200 mg tablet), which received FDA approval on April 12,2013 1
- WC2031 (doxycycline hyclate delayed-release 200 mg tablet), which demonstrated comparable efficacy to twice-daily generic doxycycline for urogenital chlamydia infections 1
Clinical Implications of Different Formulations
Gastrointestinal Tolerability
- Doxycycline hyclate delayed-release formulations may cause fewer gastrointestinal side effects compared to immediate-release formulations
- Research shows enteric-coated doxycycline hyclate pellets in capsules have significantly better gastrointestinal tolerability compared to doxycycline monohydrate 2
- WC2031 (delayed-release doxycycline) showed lower rates of nausea and vomiting (13% vs 21% and 8% vs 12%, respectively) compared to immediate-release doxycycline 1
Anti-inflammatory Applications
- A specific 40 mg formulation of doxycycline (30 mg immediate-release and 10 mg delayed-release beads) has been developed for its anti-inflammatory properties in treating rosacea 3
- This formulation provides sub-antimicrobial doses that reduce inflammation without producing drug concentrations required to treat bacterial diseases 3
Important Considerations When Prescribing Doxycycline
Administration Guidelines
- Take with a full glass of water to reduce risk of esophagitis and esophageal ulceration 1
- Take during meals while sitting or standing to prevent esophageal irritation 1
- Maintain upright position for at least 1 hour after taking doxycycline 1
Common Adverse Effects
- Gastrointestinal: nausea, vomiting, diarrhea, dysphagia 1
- Dermatological: photosensitivity, rash 1
- Serious but rare: Stevens-Johnson syndrome, toxic epidermal necrolysis, benign intracranial hypertension 1
Contraindications
- Children under 8 years of age (risk of permanent teeth discoloration) 1
- Pregnancy and breastfeeding 1
- Hypersensitivity to tetracyclines 1
Conclusion
When prescribing doxycycline, it's important to recognize that only doxycycline hyclate is available in delayed-release formulations, while doxycycline monohydrate is only available as an immediate-release product. The delayed-release formulations may offer advantages in terms of reduced gastrointestinal side effects and improved adherence due to once-daily dosing in some cases.