Antibioticoterapia e analgesia na pomba

Tratamento iniciado em 22/1/2010, 23h

Butorfanol 2 mg/kg IM (*)
Enrofloxacina 25 mg/kg IM (** o autor sugere via SC, mas nem eu nem a pomba tivemos problemas com via IM)

(*) Sobre reconhecimento e manejo da dor em aves, encontrei as notas de conferência Avian Anesthesia, no site do VIN. Segue trecho do artigo abaixo (em inglês).

"Understanding and managing pain in birds is difficult when compared to mammals. Birds clearly experience pain but analgesics are poorly studied in birds, especially psittacines.13, 17 It is reasonable to assume that pain can impede avian patient recovery just as has been proven in other animals.17 Birds may possess different types and quantities of opioid (pain) receptors when compared to mammals.17 With the current limited studies, birds seem to require a relatively high dose of selected analgesics to produce 'analgesia', further supporting that birds probably do have differences in opioid receptors, or respond to pain differently when compared to mammals.17 For example, studied umbrella cockatoos had no discernable analgesic response (compared to saline) when given high doses of fentanyl (80-100 times more potent than morphine) and only 4 of 7 had some measurable analgesia when given 10 times the 'high dose.'18

The recognition of pain is very important in avian medicine. As is true of many wild animals, birds tend not to show overt signs of pain (vocalizing) as obvious distress behaviors may attract unwanted attention. Even some physiologic measures of pain such as increased heart rate are not always seen in 'painful' birds.19 As clinicians, we often use intuition or even common sense when evaluating pain in birds. For example, a bird with a recent fracture or just recovering from an invasive procedure (hysterectomy) is likely experiencing pain. But also watch for birds that are guarding a limb, picking feathers over a limited area, acting aggressive, having focal muscle contractions, shivering, anorexic, or intensively fearful or phobic in response to basic handling or approaches (fear of a person touching a painful area or falling on a sore keel). It is the subtle, and not overt, signs of pain that more likely predominate in painful avian patients.

The first steps to resolving pain are to recognize the source of pain and reduce discomfort. For example, splinting a fractured leg or covering an open wound with a light bandage may instantly reduce pain and anxiety. Other ways to reduce anxiety and pain include placing the avian patient in a quiet, warm environment and removing cage 'furniture' and making food and water easily accessible to decrease painful movements.19

Clinically, pain management is difficult to assess in birds using the current recommended analgesics. Despite the uncertainties in bird responses and until additional studies are conducted, pain management should still be encouraged with avian patients. Butorphanol is recommended for severe pain and is given at 1-3 mg/kg IM q 6-24 hrs.17, 19 Butorphanol given at 1 mg/kg also has sparing-sparing effects, in addition to analgesic properties, in studied birds.19 Clinically, butorphanol given at 2-4 mg/kg IM or per os seems to be safe and offers relief to some avian patients. Relief may be evidenced as a calming effect on the bird. Again, it is uncertain whether this calming effect is due to sedation from the high dose of butorphanol or true analgesia. Banamine, given at 1-5 mg/kg IM q 24 hrs, may also provide some analgesia.13 Intestinal and renal side-effects from banamine use (doses as low as 0.1 mg/kg induced histologic renal lesions in studied quail) have been reported in numerous bird species.19 Clinically, aspirin given at 5-10 mg/kg PO q 24 hrs seems to help. Both carprofen (1 mg/kg SC or 2-4 mg/kg PO q 8-12 hrs) and ketoprofen (2 mg/kg IM or SC q 8-24 hrs) are popular analgesics used in avian medicine.19 As the side effects of all analgesics have not been studied in birds, these drugs should be used carefully in avian patients."

Fonte: ECHOLS MS. Avian Anesthesia. WESTERN VETERINARY CONFERENCE 2004.



(**) Sobre enrofloxacina em aves, encontrei especificamente o artigo abaixo, o qual reproduzo na íntegra:

Enrofloxacin in Birds
Western Veterinary Conference 2003
Keven Flammer, DVM, DABVP (Avian)
Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University
Raleigh, NC, USA

OBJECTIVES
How to use enrofloxacin in avian practice to maximize efficacy and ease administration.

Key Points
- Baytril is not a diagnostic test.
- Enrofloxacin must be dosed appropriately. Food and water based administration achieves much lower plasma concentrations than oral or IM administration. Intramuscular administration can cause severe irritation at the site of injection.
- Flavoring of oral suspensions can improve acceptance.

OVERVIEW
Enrofloxacin is bactericidal, widely distributed to tissues and excreted primarily through renal tubular secretion and glomerular filtration. Enrofloxacin is partially metabolized by the liver to ciprofloxacin, an equipotent metabolite. The amount of ciprofloxacin produced varies by species and may contribute slightly to antimicrobial activity. Oral administration is well tolerated; intramuscular administration causes irritation at the site of injection and is not recommended for repeated use in birds. Enrofloxacin can reduce normal alimentary tract flora and render birds more susceptible to secondary infections by yeast and anaerobes. Other side effects at recommended doses are uncommon in birds.

Enrofloxacin is active against many gram-negative bacteria at concentrations achievable in birds. Resistance is occasionally reported for E. coli, Klebsiella, and Acinetobacter, and frequently reported for Pseudomonas aeruginosa2,3. Enrofloxacin has good activity against Staphylococcus and Mycoplasma., limited activity against Streptococcus, and poor activity against Enterococcus and anaerobes. Enrofloxacin may reduce the clinical signs of chlamydiosis, but is inconsistent in eliminating infection.

Pharmacodynamic studies suggest that the efficacy of enrofloxacin is concentration dependent and that there is a significant post antibiotic effect after dosing. Treatment success correlates best with achieving high peak plasma concentrations (e.g., where Cmax is 3-10x MIC). This has clinical implications. For example, the route of administration (in addition to the dose) influences the peak concentration achieved in the bird. Peak concentrations achieved by IM injection are greater than SQ injection > oral administration > food-based medication > water based medication. If the MIC of the target organism is known, the efficacy of enrofloxacin can be better predicted and the most appropriate route of administration selected. For example, water-based medication is unlikely to be effective against pathogens with a MIC > 0.06 ug/ml, but oral medication at standard doses is often effective against pathogens with a MIC < 0.25 ug/ml. Enrofloxacin may be effective when relatively high doses are given once daily. The major disadvantage to using higher doses less frequently is the risk of toxicity (e.g., retinal damage in cats), although toxic effects have not been reported in birds.

Some observations from our research and clinical practice:

1. Oral administration of the injectable formulation of Baytril (22.7 mg/ml) achieves plasma concentrations similar to giving suspended crushed tablets orally. However, the injectable formulation can be unpalatable, even when flavored. We have seen better acceptance when the meat-flavored tablets are compounded with Syrpalta (a grape flavoring). The stability of the compounded drug is unknown so we recommend refrigeration and discard in 2 weeks.

2. Flavored drug can sometimes be applied to a favorite food (e.g., cracker), allowing owners to easily dose their bird.

3. Repeated IM injection can cause severe muscle irritation. Limited data and clinical experience indicates that SQ injection into a pocket of fluids can provide high peak concentrations without significant irritation. We routinely use this route in very ill birds to initiate therapy, and then switch to oral medication when the patient is stable.

4. The injectable formulation can be used to medicate drinking water (200 mg/L), but it achieves low plasma concentrations (< 0.1-0.4 ug/ml). This route should only be used if the MIC of the target pathogen is less than 0.06 ug/ml. Inappropriate use of Baytril medicated water can result in treatment failure and microbial resistance.

5. A dose of 15 mg/kg given twice daily maintains plasma concentrations that are effective for treating susceptible gram-negative bacterial infections in most psittacine species. Senegal parrots metabolize enrofloxacin more quickly and may respond better to q8 hour dosing. We have been experimenting with once-daily dosing and have clinically found 25 mg/kg orally or SQ q24 hours to be effective in many situations.

6. Enrofloxacin may reduce normal gut flora, making the patient susceptible to secondary alimentary tract infections by yeast, megabacteria (avian gastric yeast), and Clostridium sp.

Summary

Enrofloxacin is active against many of the most common bacterial pathogens affecting psittacine birds. Proper dosing is needed to achieve treatment success and avoid microbial resistance.

References

1. Flammer K.: Antimicrobial Therapy. In, Ritchie B.W., Harrison and Harrison, L.R. (eds.): Avian Medicine, Principles and Application. Lake Worth, Florida, Wingers Publishing, 1994:434-456.

2. Intorre L, Mengozzi G, Bertini S, Bagliacca M, Luchetti E, Soldani G: The plasma kinetics and tissue distribution of enrofloxacin and its metabolite ciprofloxacin in the Muscovy duck [published erratum appears in Vet Res Commun 1997 May;21(4):240]. Vet Res Commun 21:127-136, 1997

1. Flammer K, Aucoin DP, Whitt DA, Prus SA: Plasma concentrations of enrofloxacin in African grey parrots treated with medicated water. Avian Dis 34:1017-1022, 1990

2. Flammer K, Aucoin DP, Whitt DA: Intramuscular and oral disposition of enrofloxacin in African grey parrots following single and multiple doses. J Vet Pharmacol Ther 14:359-366, 1991

3. Knoll U, Glunder G, Kietzmann. Comparative study of the plasma pharmacokinetics and tissue concentrations of danofloxacin and enrofloxacin in broiler chickens. J Vet Pharmacol Therap. 1999;22:239-246.

4. Flammer K, Whitt-Smith D. Plasma concentrations of enrofloxacin in psittacine birds offered water medicated with 200 mg/l of the injectable formulation of Baytril. J Avian Med Surg. In press.

Fonte: FLAMMER K. Enrofloxacin in Birds. WESTERN VETERINARY CONFERENCE 2003.