Usage
This combination is primarily used in veterinary medicine, specifically for respiratory infections in livestock (cattle, pigs, poultry) where mucus buildup is present. It is effective against doxycycline-susceptible bacteria. It is sometimes used for companion animals.
Pharmacological Classification:
- Doxycycline: Tetracycline antibiotic (bacteriostatic)
- Bromhexine: Mucolytic, expectorant
Mechanism of Action:
Doxycycline inhibits bacterial protein synthesis by binding to the 30S ribosomal subunit, thus preventing bacterial growth. Bromhexine reduces mucus viscosity by depolymerizing mucopolysaccharides. This facilitates easier expectoration (coughing up phlegm), thereby improving doxycycline’s penetration into the respiratory tract for enhanced antibacterial action.
Alternate Names
- Bromodox
- Bronchidox
- Doxivet
- Other regional variations may exist.
How It Works
Pharmacodynamics:
Doxycycline, a bacteriostatic antibiotic, exerts its effect by binding to the bacterial 30S ribosomal subunit, inhibiting protein synthesis and impeding bacterial growth. Bromhexine, a mucolytic, breaks down mucopolysaccharides, reducing mucus viscosity, and improving airway clearance.
Pharmacokinetics:
- Doxycycline: Absorption is rapid and almost complete (approximately 95%) after oral administration. It distributes widely in body tissues, but penetration into the cerebrospinal fluid is poor. Metabolism occurs in the liver, and the drug is primarily eliminated through the kidneys. There are documented interactions with certain CYP450 enzymes (enzyme inhibition).
- Bromhexine: Well-absorbed after oral administration, with significant first-pass metabolism in the liver. It has a bioavailability of approximately 20%. It distributes widely into tissues including crossing the blood brain barrier and placenta. Primarily excreted in the urine as metabolites.
Mode of Action:
Doxycycline acts by binding to the bacterial 30S ribosomal subunit. This binding inhibits protein synthesis essential for bacterial growth and survival. Bromhexine acts on the mucus-producing cells in the respiratory tract, breaking down the structure of mucopolysaccharides in the mucus.
Receptor Binding, Enzyme Inhibition, or Neurotransmitter Modulation:
Doxycycline exhibits no significant receptor binding or neurotransmitter modulation. Its main action is through bacterial ribosomal binding. However, it is associated with certain CYP450 enzyme inhibition, which may cause drug interactions. Bromhexine works at the cellular level on mucus-secreting cells, causing structural changes in mucopolysaccharides but is not known for receptor binding or neurotransmitter modulation.
Elimination Pathways:
- Doxycycline: Renal excretion, hepatic metabolism (CYP enzyme interactions), and elimination in feces.
- Bromhexine: Primarily renal excretion as metabolites.
Dosage
Dosage is highly species-specific and depends on the animal’s weight, age, and the particular condition being treated. Always consult a veterinary specialist before administering. The following are examples for illustration only:
Standard Dosage
Adults (Animal):
- Cattle, Sheep, Goats: 1.0 ml per 10 kg body weight intramuscularly.
- Pigs: 0.5-1.0 ml per 10 kg body weight intramuscularly.
- Poultry: Dosages are generally calculated in mg/kg body weight and administered via drinking water. Example: 10 mg doxycycline + 1 mg bromhexine/kg live weight/day for broiler chickens for 4-5 days, or 0.5 ml of a specific solution per 1 L of drinking water for 3-5 days.
Children (Animal):
Consult a veterinarian for appropriate pediatric dosing, as it’s weight-dependent.
Special Cases:
- Animals with Renal Impairment: Use with caution; dose adjustments may be necessary.
- Animals with Hepatic Dysfunction: Use with caution; dose adjustments may be necessary.
- Pregnant/Lactating Animals: Use cautiously; some sources advise against use, especially during pregnancy. Short-term use in lactating animals may be possible, however the long-term effects are unknown. Alternative safer options might exist.
Clinical Use Cases
The clinical use cases provided below are examples from various sources for illustrative purposes only and do not constitute veterinary medical advice. Always consult with a veterinary specialist for specific dosage recommendations in these clinical settings:
- Respiratory Infections: Commonly used for pneumonia, bronchitis, and other respiratory infections complicated by mucus buildup.
Dosage Adjustments
Adjustments are based on renal/hepatic function, age, weight, concurrent medications, and the severity of the infection. A veterinarian should always make these determinations.
Side Effects
Common Side Effects:
- Gastrointestinal upset (vomiting, diarrhea)
Rare but Serious Side Effects:
- Allergic reactions (hypersensitivity)
Long-Term Effects:
- Tooth discoloration (in young animals with developing teeth)
Adverse Drug Reactions (ADR):
- Severe allergic reactions
Contraindications
- Known hypersensitivity to doxycycline, bromhexine, or tetracyclines.
- Severe hepatic impairment.
- Pregnancy (especially in the first trimester). Use in later pregnancy or lactation should only be undertaken after careful risk-benefit assessment by a veterinarian.
- Concurrent use with penicillin, cephalosporin antibiotics, or certain mineral supplements.
Drug Interactions
- Doxycycline: Interacts with antacids, iron supplements, calcium supplements, bismuth subsalicylate, barbiturates, theophylline, insulin, aminophylline, methoxyflurane, some anticoagulants, other antibiotics.
- Bromhexine: Interacts with some antibiotics (erythromycin, amoxicillin), antitussives, and potentially antihypertensive medications.
Pregnancy and Breastfeeding
- Pregnancy: Contraindicated, especially during the first trimester due to potential risk to the developing fetus (tooth discoloration, skeletal development issues).
- Breastfeeding (Lactation): Not recommended due to potential drug excretion in milk and unknown effects on nursing offspring. Limited information suggests that short-term use might be considered in special cases after a thorough risk-benefit assessment by a veterinarian.
Drug Profile Summary
- Mechanism of Action: Doxycycline: inhibits bacterial protein synthesis; Bromhexine: reduces mucus viscosity.
- Side Effects: Gastrointestinal upset, allergic reactions.
- Contraindications: Hypersensitivity, severe hepatic impairment, pregnancy (especially first trimester).
- Drug Interactions: Antacids, iron supplements, calcium, other antibiotics.
- Pregnancy & Breastfeeding: Contraindicated/not recommended.
- Dosage: Varies greatly depending on the animal species and the specific formulation; consult a veterinarian.
- Monitoring Parameters: Clinical signs of infection, hydration status.
Popular Combinations (Veterinary)
Often used alone. Combination preparations available that also contain lincomycin, tylosin, or other antimicrobial agents.
Precautions
- Verify bacterial susceptibility to doxycycline.
- Monitor for adverse reactions.
- Use caution in animals with renal/hepatic impairment.
- Avoid use in pregnant or lactating animals unless deemed absolutely necessary by a veterinarian.
- Ensure adequate hydration.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Bromhexine + Doxycycline?
A: The dosage is highly variable and depends on species, weight, and formulation. Contact a veterinarian for specific guidance.
Q2: How should this medication be administered?
A: Common routes include intramuscular injection, oral administration via drinking water or feed, and tablets. This depends on the species and specific formulation.
Q3: What are the common side effects?
A: Gastrointestinal issues like vomiting and diarrhea are commonly reported.
Q4: Is this combination safe for pregnant or lactating animals?
A: Generally contraindicated during pregnancy, especially the first trimester. Not typically recommended for lactating animals due to potential excretion in milk and risks to offspring. Veterinarian consultation is crucial before considering use in these situations.
Q5: What are the contraindications for this drug?
A: Known hypersensitivity to the components, severe liver disease, and use with certain medications.
Q6: What if a dose is missed?
A: Consult your veterinarian. Do not double the next dose.
Q7: What if I observe an allergic reaction?
A: Discontinue the medication immediately and consult a veterinarian.
Q8: How should this drug be stored?
A: Store in a cool, dry place away from direct sunlight and out of reach of children. Follow manufacturer’s instructions regarding temperature. Pay attention to expiration dates.
Q9: Can this combination be used with other antibiotics?
A: Some antibiotics are contraindicated to be given simultaneously. Consult a veterinarian before using other medications concurrently.
