Qs i got wrong on katzung and trevors

Which of the following is an accepted therapeutic indication for the use of antimuscarinic drugs? (A) Atrial fibrillation (B) Botulinum poisoning (C) Chronic obstructive pulmonary disease (COPD) (D) Glaucoma (E) Postoperative urinary retention

C . Atrial fibrillation and other arrhythmias are not responsive to antimuscarinic agents. Botulinum poisoning is associated with parasympathetic blockade. Parkinson's disease, not Huntington's, is partially responsive to antimuscarinic drugs. Antimuscarinic drugs tend to cause urinary retention and may precipitate or exacerbate glaucoma. Bronchospasm is mediated in part by vagal outflow in many patients with COPD and in some with asthma.

. A 65-year-old woman with impaired renal function and a necrotic ulcer in the sole of her right foot is admitted to the ward from the emergency department. She has long-standing type 2 diabetes mellitus and you wish to examine her retinas for possible vascular changes. Which of the following drugs is a good choice when pupillary dilation—but not cycloplegia—is desired? (A) Isoproterenol (B) Norepinephrine (C) Phenylephrine (D) Pilocarpine (E) Tropicamide

C. it works not as long as E.

Mr Green, a 54-year-old banker, had a cardiac transplant 6 months ago. His current blood pressure is 120/70 mm Hg and heart rate is 100 bpm. Which of the following drugs would have the least effect on Mr Green's heart rate? (A) Albuterol (B) Epinephrine (C) Isoproterenol (D) Norepinephrine (E) Phenylephrine

E Heart transplantation involves cutting of the autonomic nerves to the heart. As a result, autonomic nerve endings degenerate, and cardiac transmitter stores are absent for 2 years or longer after surgery. Therefore, indirect-acting sympathomimetics are ineffective in changing heart rate. All the drugs listed are direct-acting, and all but phenylephrine have significant effects on β receptors. Phenylephrine usually causes reflex bradycardia, which requires intact vagal innervation.

what drug behaves as a mixed alpha and beta agonist. It would raise systolic, diastolic, CO, and heart rate.

epinephrine

what drug would most likely block the effects on the heart of an IV infusion of phenylephrine ?

this question is essentially asking, what blocks the M2 receptor. the answer is Atropine. phenylephrine will decrease HR due to reflex bradycardia from the increase in BP due to Alpha 1 effect. Atropine will give tachycardia on high enough doses. atropine is a muscarinic antagonist.