Dophexine® highly appreciated by swine veterinarians!
Bromhexine, the active ingredient of Dophexine® 20 mg/g, has been widely used for respiratory conditions in calves for years. The veterinary medicine was previously only registered in the Netherlands and only for calves. Due to the great success of this product in the veal sector, Dopharma registered Dophexine® 20 mg/g in several European countries and for multiple animal species. Therefore, Dophexine® can now be used not only for calves but also for pigs, chickens, turkeys, and ducks.
How does bromhexine work1?
Bromhexine is a mucoregulator. Mucus is an important component of the nonspecific defence mechanisms in the respiratory tract. The respiratory tract, due to continuous breathing, is in intensive contact with the outside world. Mucus ensures that pathogens, entering the respiratory tract along with the inhaled air, do not come into direct contact with the bronchial and alveolar tissue. Additionally, together with the ciliated epithelium, mucus ensures that the pathogens can be effectively transported upwards to the throat. This interplay between mucus and cilia is essential as the first line of defence. For the proper functioning of this clearance of the respiratory tract, it’s important that the mucus is sufficiently liquid and not too thick and elastic. Characteristic of pathological mucus are high viscosity and elasticity.
Bromhexine has two main effects:
- Bromhexine activates the secretion of the seromucous glands in the respiratory system. Due to the increased production of the goblet cells specifically in the airways, the secretion becomes thinner and more watery, thereby restoring the viscosity and elasticity of the protective mucus layer.
- Additionally, bromhexine promotes mucus mobilisation by the cilia.
Both effects contribute to an effective restoration of bronchial drainage. This improves the functioning and defence mechanisms of the lungs.
In the figure below, you can see the effect of treatment with bromhexine (day 5 – day 10) on the viscosity of bronchial mucus in minipigs2.
Secondary effects of Bromhexine
When searching the scientific literature for the properties of bromhexine, you will notice that various, at first glance, very interesting effects are described. For instance, the concentration of different antibiotics in the serum and nasal secretions is increased with simultaneous administration of bromhexine. Bromhexine is also attributed with anti-inflammatory and antioxidant properties. However, these beneficial effects are quite small and do not compare to the beneficial effect of bromhexine as a mucoregulator!
How can you use Dophexine® 20 mg/g in practice?
Dophexine® is used as a mucolytic treatment for respiratory conditions. This is done both as monotherapy and in combination with antibiotics.
In combination with antibiotics
Dophexine® is used in combination with antibiotics for severe bacterial infections. During a bacterial respiratory infection, the consistency of bronchial secretions will deteriorate. Treatment with Dophexine® will restore bronchial drainage and improve the lung’s defence mechanism.
As monotherapy:
Dophexine® can also be used as monotherapy. In practice, we mainly see two applications for this:
- Dophexine® is used in pigs that cough but do not show other clinical symptoms of disease. This may be the case with mild bacterial infections (for which antibiotic treatment is not necessary) or if other conditions are causing the described abnormalities of bronchial mucus.
- Dophexine® is used as a follow-up treatment to an antibiotic regimen. Sometimes, after an effective antibiotic treatment, there is still some coughing present in the pigs. In such cases, the composition of the mucus and the function of the cilia might not have fully recovered. As a result, clearing the airways adequately is difficult. In this situation, it will be beneficial to treat with Dophexine® 20 mg/g in order to use bromhexine as an expectorant.
Dophexine® 20 mg/g is highly water-soluble1
Dophexine® contains 20 mg of bromhexine hydrochloride per gram of product. Bromhexine is not very water-soluble, which is why citric acid has been added to Dophexine® as an important auxiliary substance. This allows for the preparation of an acidic, concentrated premix without any issues for use with a dosing system.
The medicated drinking water is stable for 24 hours. Therefore, when setting a doser at 1% and a water consumption of 10% of the body weight/day, a presolution of 25 grams of Dophexine® per litre of water is usually prepared.
The maximum solubility of Dophexine® in water is 100 g/l at 20 °C. In the table below, you will find the solubility at two different concentrations.
| Concentration of Dophexine® in water at 20 ⁰C | Solubility Time |
| 10 grams of Dophexine®/litre | 3 minutes |
| 100 grams of Dophexine®/litre (max) | 12 minutes |
Summary1 of the characteristics of Dophexine®
| Concentration | 20 mg bromhexine hydrochloride /gram of Dophexine® |
| Pharmaceutical form | Powder for use in drinking water/milk |
| Target species | Cattle (calves), pigs, chickens, turkeys, ducks |
| Indication | Mucolytic treatment of congested respiratory tract. |
| Dosage | 2,5 g of Dophexine® per 100 kg of body weight per day, administered during 3 to 10 consecutive days. |
| Withdrawal period pig, chicken, turkey, duck | Meat and offal: 0 days. Not for use in birds producing eggs for human consumption, during and 4 weeks before the laying period. |
| Withdrawal period calf | Meat and offal: 2 days Not authorised for use in animals producing milk for human consumption. |
| Shelf life | As packaged for sale: 30 months. After first opening of the immediate packaging: 3 months. After reconstitution in drinking water according to directions: 24 hours. After dilution in milk (replacer) according to directions: 6 hours. |
References
- https://db.cbg-meb.nl/MarketedAuth/v125094-90sr-26102020.pdf
- Martin GP et al. The effect of bromhexine hydrochloride in the viscoelastic properties of mucus from the min-pig. Eur. Respir. J 1990;3:392-396
