Page 725 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

700 CHAPTER 3

VetBooks.ir Table 3.4 Common drugs used for the treatment of inflammatory airway disease (IAD) and heaves

DRUG DOSE ROUTE* COMMENTS
Bronchodilators
Albuterol 0.8–2 μg/kg q1–3 h Inhalation: MDI Rapid onset of duration of activity with short duration of
effect (0.5–3 hours)
Ipratropium bromide 0.5–1 μg/kg q6 h Inhalation: MDI Rapid onset of action with moderately long-lasting effect
(4–6 hours). No known side-effects
Salmeterol 63–210 μg q8 h Inhalation: MDI Rapid onset of action with long-lasting effect (6–8 hours)
Fenoterol 1–2 mg Inhalation: MDI Rapid onset of action
Clenbuterol 0.8–3.2 μg/kg q12 h P/o Also increases the rate of mucociliary clearance. Side-effects
Inhalation: nebulised include sweating, trembling, tachycardia and excitement
0.8 μg/kg q12 h I/v or i/m
Aminophylline 5–10 mg/kg q8–12 h P/o or i/v Therapeutic plasma concentrations vary among horses and
margin of safety is very narrow. May cause excitement.
Dilute i/v dose in 1 litre of saline and administer over 30–60
minutes while monitoring animal for signs of toxicity
Corticosteroids
Dexamethasone 0.04–0.1 mg/kg q24 h I/v, i/m, or p/o Increased dosage required for oral administration due to
(0.2 mg/kg q24 h for p/o) limited bioavailability with oral dosing
Dexamethasone 0.04–0.06 mg/kg q3 d I/m Depot form of dexamethasone
21-isonicotinate
Prednisolone 1.1–2.2 mg/kg q24 h P/o Good GI absorption
Isoflupredone acetate 10–14 mg q24 h I/m Repeated administration has induced significant
hypokalaemia in other species
Triamcinolone 0.09 mg/kg once I/m Depot drug with prolonged effect after single dose
acetonide (e.g. 3–5 weeks)
Beclomethasone 1–8 μg/kg q12 h Inhalation: MDI Minimal systemic effects due to low dose plus delivery by
dipropionate inhalation. Actual dose depends on delivery system used
Fluticasone propionate 1–6 μg/kg q12 h Inhalation: MDI Minimal systemic effects due to low dose plus delivery by
inhalation
Cromogens
Sodium cromoglycate 80–200 mg q12–24 h Inhalation: Mast cell stabiliser. Prophylactic use only
nebulised
Nedocromil sodium 24 mg q12 h Inhalation: MDI Mast cell stabiliser. Prophylactic use only
Other
Interferon-alpha 50–150 U q24 h for 5 d Oral Reduced airway inflammation in horses with IAD

*Inhaled drugs must be administered using an equine delivery device/mask in combination with a metered dose inhaler (MDI) or nebulisation system.

to inhaled antigens (aeroallergens). Although mul- heaves exacerbation. It is not currently known
tiple agents in the environment may act as aller- whether heaves is a sequela to IAD in some horses.
gens, moulds and dusts in improperly baled hay A genetic propensity to develop heaves has also
are most frequently implicated as the cause of been suggested.