Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 38-30 Clonidine & Other Sympatholytic Antihypertensives Overdose + Key Features Download Section PDF Listen +++ ++ Symptoms usually resolve in 24 hours Deaths are rare Similar symptoms may occur after application of topical nasal decongestants chemically similar to clonidine; for example Oxymetazoline Tetrahydrozoline Naphazoline Brimonidine Apraclonidine Tizanidine + Clinical Findings Download Section PDF Listen +++ ++ Bradycardia Hypotension Miosis Respiratory depression Coma Transient hypertension occasionally occurs as a result of peripheral α-adrenergic effects + Diagnosis Download Section PDF Listen +++ ++ Clinical Not detected in usual toxicology screenings + Treatment Download Section PDF Listen +++ ++ Symptomatic treatment is usually sufficient Maintain blood pressure with intravenous fluids Dopamine can also be used for hypotension Atropine is usually effective for bradycardia Activated charcoal Administer 60–100 g orally or via gastric tube, mixed in aqueous slurry Do not use for comatose or convulsing patients unless it can be given by gastric tube and the airway is protected by a cuffed endotracheal tube There is no specific antidote Tolazoline should not be used for clonidine overdose because its effects are unpredictable Naloxone has had anecdotal success