Adverse reactions to<unk>  include ventricular fibrillation, supraventricular or ventricular tachycardia, dizziness, nausea, blurred vision, loss of balance, dilated pupils, photophobia, dry mouth and potentially extreme confusion, deliriant hallucinations, and excitation especially among the elderly. These latter effects are because<unk>  is able to cross the blood–brain barrier. Because of the hallucinogenic properties, some have used the drug recreationally, though this is potentially dangerous and often unpleasant. In overdoses,<unk>  is poisonous.<unk>  is sometimes added to potentially addictive drugs, particularly antidiarrhea opioid drugs such as diphenoxylate or difenoxin, wherein the secretion-reducing effects of the<unk>  can also aid the antidiarrhea effects. Although<unk>  treats bradycardia (slow heart rate) in emergency settings, it can cause paradoxical heart rate slowing when given at very low doses (i.e. 50 is estimated to be 453 mg per person (by mouth) with a probit slope of 1.8. The antidote to<unk>  is physostigmine or pilocarpine. A common mnemonic used to describe the physiologic manifestations of<unk>  overdose is: "hot as a hare, blind as a bat, dry as a bone, red as a beet, and mad as a hatter". These associations reflect the specific changes of warm, dry skin from decreased sweating, blurry vision, decreased lacrimation, vasodilation, and central nervous system effects on muscarinic receptors, type 4 and 5. This set of symptoms is known as anticholinergic toxidrome, and may also be caused by other drugs with anticholinergic effects, such as hyoscine hydrobromide (scopolamine), diphenhydramine, phenothiazine antipsychotics and benztropine.
Atropine
Neostigmine
Physostigmine
Suxamethonium chloride
Pyridostigmine
Tripelennamine
Ephedrine
Gantacurium chloride