... if bradycardia is present. Diazepam (0.25-0.5 mg / kg, IV) can be given if CNS signs (eg, apprehension, shaking) are present. Serum electrolytes (ie, potassium, sodium, chloride) should be assessed and corrected as needed. Yohimbine, which is a specific a 2 -adrenergic antagonist, can also be used at 0.1 mg / kg, IV, and repeated in 2-3 hr if needed. See Also Toxicities from Over-the-counter Drugs Overview Cold and Cough Medications Antihistamines Decongestants Pseudoephedrine and Ephedrine Analgesics Nonsteroidal Anti-inflammatory Drugs ... colds, hay fever or other upper respiratory allergies, or sinusitis. Imidazolines are sympathomimetic agents, with primary effects on Î ±-adrenergic receptors and little if any effect on Î ²-adrenergic receptors. Oxymetazoline is readily absorbed orally. Effects on Î ±-receptors from systemically absorbed oxymetazoline hydrochloride may persist for up to 7 hr after a single dose. The elimination half-life in humans is 5-8 hr. It is excreted unchanged both by the kidneys (30 %) and in feces (10 %). Clinical Findings: In dogs, signs of intoxication may include ...