Doryx 50mg DR Tablets
Overview
What is this medicine?
How to Use This Medicine
To get the most benefit from your medication, follow your doctor's instructions carefully. Read all the information provided to you and follow the instructions closely. Continue taking your medication as directed by your doctor or healthcare provider, even if you start to feel better.
Special Instructions for Taking Your Medication
Take your medication with food or on an empty stomach, as directed by your pharmacist. Some medications may not work as well if taken with certain foods or products.
Avoid taking your medication at the same time as milk, dairy products, or other foods that contain calcium, as this may reduce its effectiveness. If you have questions, consult your doctor or pharmacist.
Drink plenty of non-caffeinated liquids, unless your doctor advises you to limit your fluid intake.
Interactions with Other Medications and Substances
Do not take the following medications or substances within 2 hours of taking your medication: bismuth (Pepto-Bismol), calcium, iron, magnesium, zinc, multivitamins with minerals, colestipol, cholestyramine, didanosine, or antacids.
Take your medication with a full glass of water to help prevent throat irritation.
Do not lie down after taking your medication. Ask your pharmacist how long you should wait before lying down.
Swallowing Your Medication
Swallow your medication whole. Do not chew or crush it.
If your doctor instructs you to break the tablet, you may do so. However, be careful not to crush the pellets inside the tablet.
You may sprinkle the contents of the tablet on applesauce, but be careful not to crush or damage the pellets. Do not mix the medication with hot applesauce, and swallow the mixture immediately. Do not store it for later use.
Storing and Disposing of Your Medication
Store your medication at room temperature, protected from light and moisture. Do not store it in a bathroom.
Do not take your medication if it is past its expiration date or if it has not been stored properly.
Check with your pharmacist or doctor if you have any questions about storing or disposing of your medication.
What to Do If You Miss a Dose
If you miss a dose, take it as soon as you remember.
If it is close to the time for your next dose, skip the missed dose and continue with your regular schedule.
* Do not take two doses at the same time or take extra doses.
Lifestyle & Tips
- Take with a full glass of water (at least 8 ounces) to prevent irritation of the esophagus.
- Remain upright for at least 30 minutes (preferably 1 hour) after taking the medication to prevent esophageal irritation or ulceration.
- Avoid excessive exposure to sunlight or artificial UV light (tanning beds) while taking this medication and for several days after stopping it, as it can cause severe sunburn (photosensitivity). Use sunscreen and wear protective clothing.
- Avoid taking antacids, iron supplements, calcium supplements, or dairy products within 2-3 hours before or after taking doxycycline, as they can interfere with its absorption.
- Complete the full course of medication as prescribed, even if you start feeling better, to prevent the infection from returning and to reduce the risk of antibiotic resistance.
- This medication may cause dizziness; avoid driving or operating machinery until you know how it affects you.
Available Forms & Alternatives
Available Strengths:
Generic Alternatives:
Dosing & Administration
Adult Dosing
Condition-Specific Dosing:
Pediatric Dosing
Dose Adjustments
Renal Impairment:
Hepatic Impairment:
Pharmacology
Mechanism of Action
Pharmacokinetics
Absorption:
Distribution:
Elimination:
Pharmacodynamics
Safety & Warnings
Side Effects
Although rare, this medication can cause severe and potentially life-threatening side effects. If you experience any of the following symptoms, contact your doctor or seek medical attention right away:
Signs of an allergic reaction: rash, hives, itching, red, swollen, blistered, or peeling skin (with or without fever), wheezing, tightness in the chest or throat, trouble breathing, swallowing, or talking, unusual hoarseness, or swelling of the mouth, face, lips, tongue, or throat
Signs of liver problems: dark urine, tiredness, decreased appetite, upset stomach or stomach pain, light-colored stools, vomiting, or yellow skin or eyes
Signs of pancreatitis (pancreas problem): severe stomach pain, severe back pain, or severe upset stomach or vomiting
Chest pain or pressure, or a fast heartbeat
Difficulty urinating or changes in urine output
Fever, chills, or sore throat; unexplained bruising or bleeding; or feeling extremely tired or weak
Throat irritation or trouble swallowing
Muscle or joint pain
Rapid breathing
Flushing
Severe dizziness or fainting
Changes in skin color
Vaginal itching or discharge
Important Antibiotic-Related Side Effect:
Diarrhea is a common side effect of antibiotics. However, in rare cases, a severe form of diarrhea called Clostridioides difficile-associated diarrhea (CDAD) may occur. This condition can lead to a life-threatening bowel problem. If you experience stomach pain, cramps, or loose, watery, or bloody stools, contact your doctor immediately. Before treating diarrhea, consult with your doctor.
Rare but Serious Side Effect:
Raised pressure in the brain has been reported with this medication. In most cases, this condition resolves after the medication is stopped. However, in some cases, vision loss may occur and may be permanent. If you experience a headache or vision problems, such as blurred vision, double vision, or loss of vision, contact your doctor right away.
Other Side Effects:
Most people taking this medication do not experience severe side effects. However, some may occur. If you experience any of the following side effects, contact your doctor if they bother you or do not go away:
Diarrhea
Upset stomach or vomiting
Decreased appetite
This is not an exhaustive list of possible side effects. If you have questions or concerns about side effects, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Severe headache, especially with blurred vision, double vision, or vision loss (signs of pseudotumor cerebri)
- Severe, watery diarrhea or bloody stools, with or without fever and stomach cramps (signs of Clostridioides difficile-associated diarrhea)
- New or worsening skin rash, blistering, or peeling skin
- Signs of liver problems: yellowing of the skin or eyes (jaundice), dark urine, unusual tiredness, severe stomach pain, nausea, vomiting
- Difficulty swallowing, painful swallowing, or chest pain (signs of esophageal irritation)
- Unusual bruising or bleeding (if also taking blood thinners)
Before Using This Medicine
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
If you are currently taking any of the following medications: Acitretin, Isotretinoin, or a Penicillin.
* If you are breast-feeding or plan to breast-feed, as you may need to avoid nursing while taking this medication.
This list is not exhaustive, and it is crucial to discuss all your medications, including prescription and over-the-counter (OTC) drugs, natural products, and vitamins, with your doctor and pharmacist. Additionally, inform them about any existing health problems. Your doctor will help you determine whether it is safe to take this medication with your other medications and health conditions.
Remember, do not start, stop, or change the dose of any medication without first consulting your doctor to ensure your safety.
Precautions & Cautions
This medication may interfere with certain laboratory tests, so it is crucial to notify all your healthcare providers and laboratory personnel that you are taking this drug. Do not exceed the prescribed duration of treatment, as this may increase the risk of a second infection.
You may be more susceptible to sunburn while taking this medication, so take necessary precautions when exposed to the sun. If you experience unusual sunburn or sensitivity, inform your doctor promptly.
This drug can cause severe skin reactions, including Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and other serious conditions that may affect internal organs. These reactions can be life-threatening. Seek immediate medical attention if you experience symptoms such as red, swollen, blistered, or peeling skin; red or irritated eyes; sores in your mouth, throat, nose, eyes, genitals, or skin; fever; chills; body aches; shortness of breath; or swollen glands.
If you are using birth control pills or other hormone-based contraception, note that this medication may reduce their effectiveness. Consider using an additional form of birth control, such as a condom, to prevent pregnancy.
In children under 8 years old, this medication may cause permanent tooth discoloration (yellow-gray brown) or other tooth problems. It may also affect bone growth. If you have concerns, discuss them with your doctor. Similarly, if taken during certain stages of pregnancy, this medication may cause tooth discoloration in the unborn baby.
Although this medication is not typically recommended for children under 8 years old, there may be exceptions. Consult your doctor to determine the best course of treatment.
In some cases, adults have also experienced tooth discoloration, which may reverse after stopping the medication and undergoing dental cleaning. If you have concerns, discuss them with your doctor.
If you are pregnant or become pregnant while taking this medication, you may be at risk of harming the unborn baby. Notify your doctor immediately if you are pregnant or suspect you may be pregnant.
Overdose Information
Overdose Symptoms:
- Nausea
- Vomiting
- Diarrhea
- Liver damage (rare)
- Kidney damage (rare)
What to Do:
Seek immediate medical attention or call a poison control center (e.g., 1-800-222-1222). Treatment is supportive; gastric lavage may be considered if ingestion is recent.
Drug Interactions
Contraindicated Interactions
- Isotretinoin (increased risk of pseudotumor cerebri)
Major Interactions
- Antacids containing aluminum, calcium, or magnesium (decreased doxycycline absorption)
- Iron preparations (decreased doxycycline absorption)
- Bismuth subsalicylate (decreased doxycycline absorption)
- Sucralfate (decreased doxycycline absorption)
- Warfarin (potentiated anticoagulant effect)
- Penicillins (potential antagonism of bactericidal effect)
Moderate Interactions
- Barbiturates (e.g., phenobarbital) (decreased doxycycline half-life and efficacy)
- Phenytoin (decreased doxycycline half-life and efficacy)
- Carbamazepine (decreased doxycycline half-life and efficacy)
- Oral contraceptives (potential reduction in efficacy, though evidence is weak)
- Methotrexate (increased methotrexate toxicity)
Minor Interactions
- Live bacterial vaccines (e.g., oral typhoid vaccine) (may reduce vaccine efficacy)
Monitoring
Baseline Monitoring
Rationale: To establish baseline in patients with pre-existing hepatic impairment or for prolonged therapy, as doxycycline is metabolized by the liver to a minor extent and can rarely cause hepatotoxicity.
Timing: Prior to initiation of therapy in at-risk patients.
Rationale: To establish baseline, though doxycycline excretion is primarily non-renal, it's good practice for prolonged antibiotic use.
Timing: Prior to initiation of therapy in at-risk patients.
Routine Monitoring
Frequency: Daily to weekly, depending on indication
Target: Resolution of infection symptoms or improvement in skin condition.
Action Threshold: Lack of improvement or worsening symptoms may indicate treatment failure, resistance, or need for alternative therapy.
Frequency: Throughout therapy and for several weeks post-therapy
Target: Absence of new infections.
Action Threshold: Development of new symptoms requires evaluation and appropriate treatment (e.g., C. difficile infection).
Frequency: Daily
Target: Absence or mild, tolerable side effects.
Action Threshold: Severe or persistent side effects may require dose adjustment or discontinuation.
Symptom Monitoring
- Severe headache
- Blurred vision or vision changes (potential pseudotumor cerebri)
- Severe or persistent diarrhea (potential Clostridioides difficile-associated diarrhea)
- New or worsening rash, severe sunburn reaction (photosensitivity)
- Difficulty swallowing, chest pain, or heartburn (esophageal irritation/ulceration)
- Yellowing of skin or eyes, dark urine, abdominal pain (signs of liver dysfunction)
- Unusual bruising or bleeding (if on warfarin)
Special Patient Groups
Pregnancy
Category D. Doxycycline can cause permanent discoloration of teeth (yellow-gray-brown) and inhibition of bone growth if administered during tooth development (last half of pregnancy, infancy, and childhood to the age of 8 years). Should only be used if the potential benefit justifies the potential risk to the fetus.
Trimester-Specific Risks:
Lactation
L3 (Moderate risk). Doxycycline is excreted into breast milk. While the amount transferred is small and calcium in milk may chelate it, there is a theoretical risk of tooth discoloration and inhibition of bone growth in the nursing infant. The American Academy of Pediatrics considers tetracyclines usually compatible with breastfeeding, but caution is advised, especially with prolonged use.
Pediatric Use
Contraindicated in children under 8 years of age due to the risk of permanent tooth discoloration (yellow-gray-brown) and inhibition of bone growth. Use in children 8 years and older should be carefully weighed against the risks.
Geriatric Use
No specific dose adjustment is generally required based on age alone. However, elderly patients may have reduced renal or hepatic function, which should be considered. Monitor for adverse effects, particularly gastrointestinal upset and photosensitivity.
Clinical Information
Clinical Pearls
- Doxycycline is unique among tetracyclines in that it is primarily eliminated via non-renal pathways, making it a preferred tetracycline for patients with renal impairment.
- Delayed-release formulations like Doryx are designed to reduce gastrointestinal irritation and can be taken with or without food, unlike immediate-release forms which are best taken with food.
- Always advise patients to take doxycycline with a full glass of water and remain upright for at least 30-60 minutes to prevent esophageal irritation and ulceration.
- Photosensitivity is a common and significant side effect; counsel patients on strict sun protection measures.
- Doxycycline's anti-inflammatory properties make it useful for conditions like rosacea and acne at sub-antimicrobial doses (e.g., 20mg BID or 40mg once daily for Oracea, or 50mg daily for Doryx in some cases).
Alternative Therapies
- Other tetracyclines (e.g., minocycline, tetracycline)
- Macrolides (e.g., azithromycin, erythromycin)
- Fluoroquinolones (e.g., ciprofloxacin, levofloxacin)
- Beta-lactam antibiotics (e.g., amoxicillin, cephalexin)
- For acne: Topical retinoids, benzoyl peroxide, clindamycin, erythromycin, isotretinoin (oral)
- For rosacea: Topical metronidazole, azelaic acid, brimonidine, ivermectin