Doses - CLEMASTINE FUMARATE
Dogs: 
As an antihistamine: a) 0.5 - 1.5 mg per dog q12h (Paradis and Scott 1992)
b) 0.05 mg/kg PO q12h (Papich 1992), (White 1994)
Monitoring Parameters - 1) Efficacy; 2) Adverse Effects, if any
Client Information - Clients should understand that antihistamines may be useful for symptomatic relief of allergic symptoms, but are not a cure for the underlying disease.
Dosage Forms/Preparations/FDA Approval Status/Withholding Times - Veterinary-Approved Products: None
Human-Approved Products:
Clemastine Fumarate Oral Tablets 1.34 mg, 2.68 mg; Oral Solution 0.67 mg/5 ml; Tavist®(Sandoz) (Rx), Antihist-1® (Various) (OTC);Tavist-1 ® (Sandoz) (OTC); generic; (Rx)CLENBUTEROL HCL
Chemistry, Storage/Stability - A beta-2-adrenergic agonist, clenbuterol HCl's chemical name is1-(4-Amino-3, 5-dichlorophenyl)-2-tert-butyl aminoethanol HCl. The commercially available syrupis colorless and should be stored at room temperature (avoid freezing). The manufacturer warns toreplace the safety cap on the bottle when not in use.
Pharmacology
Like other beta-2 agonists, clenbuterol is believed to act by stimulating productionof cyclic AMP through the activation of adenyl cyclase. By definition, Beta-2 agonists have moresmooth muscle relaxation activity (bronchial, vascular and uterine smooth muscle) versus its cardiaceffects (Beta 1).Uses, Indications
Clenbuterol is approved for use in horses as a bronchodilator in the management of airway obstruction, such as chronic obstructive pulmonary disease (COPD).It has been used as a partitioning agent in food producing animals, but its use for this purpose isbanned in the USA as relay toxicity in humans has been documented.
Pharmacokinetics
After oral administration to horses, peak plasma levels of clenbuterol occur 2hours after administration and the average half life is about 10 hours. The manufacturer states thatthe duration of effect varies from 6-8 hours.Contraindications, Precautions, Reproductive Safety
The drug is contraindicated in food producing animals (legal ramifications). It should not be used in pregnant mares near full term as itantagonizes the effects of dinoprost (prostaglandin F2alpha) and oxytocin and can diminish normaluterine contractility. The label states that the drug should not be used in horses suspected of havingcardiovascular impairment as tachycardia may occur.Clenbuterol's safety in breeding stallions and brood mares has not been established.
Adverse Effects, Warnings
Muscle tremors, sweating, restlessness, urticaria and tachycardia maybe noted, particularly early in the course of therapy. Creatine kinase elevations have been noted insome horses and rarely ataxia can occur.Clenbuterol has been touted in some body building circles as an alternative to anabolic steroids formuscle development and body fat reduction, however its safe use for this purpose is in seriousquestion. Be alert for scams to divert legitimately obtained clenbuterol for this purpose.
Overdosage - Some case reports of clenbuterol overdoses have been reported in various species.
Depending on dosage and species, emptying gut may be appropriate; otherwise supportive therapyand administration of parenteral beta blockers to control heart rate and rhythm, and elevated bloodpressure may be considered.
Drug Interactions
Concomitant administration with other sympathomimetic amines (e.g., terbutaline) may enhance the adverse effects of clenbuterol. Beta blockers (e.g. propranolol) mayantagonize clenbuterol's effects. Tricyclic antidepressants or monoamine oxidase inhibitorsmay potentiate the vascular effects of clenbuterol. Use with inhalation anesthetics (e.g., halothane, isoflurane, methoxyflurane), may predispose the patient to ventricular arrhythmias, particularly inpatients with preexisting cardiac disease¯use cautiously. Use with digitalis glycosides mayincrease the risk of cardiac arrhythmias.Clenbuterol may antagonize the effects of dinoprost (prostaglandin F2alpha) and oxytocin.