You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is Anti arrhythmic drug is and explain in detail?
Refer kDT 7/e p 529 Phentolamine is a synthetic imidazoline with alpha-adrenergic antagonist activity. As a competitive alpha-adrenergic antagonist, phentolamine binds to alpha-1 and alpha-2 receptors, resulting in a decrease in peripheral vascular resistance and vasodilatation. Phenobarbital belongs to a class of drugs known as barbiturate anticonvulsants/hypnotics. Pentamidine is an antimicrobial medication used to treat African trypanosomiasis, leishmaniasis, babesiosis, and to prevent and treat pneumocystis pneumonia in people with poor immune function