Tachycardia drug side-effect

The answer is a. (Hardman, p 436J The most common side effects associated with tricyclic antidepressants are their anti muscarinic effects, which may be evident in over 50% of patients. Clinically, the anti muscarinic effects may manifest as dry mouth, blurred vision, constipation, tachycardia, dizziness, and urinary retention. At therapeutic plasma concentrations, these drugs usually do not cause changes in the EKG Direct cardiac effects of the tricyclic antidepressants are important in over dosage. 

This leaves hydralazine as the only drug of this kind available to date on the U.S. market for chronic use. The total picture of the mechanism of action of hydralazine is still not clearly defined but there is general agreement that direct relaxation of the vasculature leading to reduced peripheral resistance is the principal component of its mechanism of action. This drug has stood the test of time despite such side effects as headache, tachycardia and a syndrome which resembles acute systemic lupus erythematosus, often called "hydralazine syndrome" (1). 

Minoxidil is a peripheral vasodilator that directly relaxes vascular smooth musculature, thus, lowering systolic and diastolic pressure. Its action is linked to the activation of calcium channels. Open calcium channels cause hyperpolarization of smooth muscle cells, which in turn, reduces the flow of calcium ions into the cell, which is necessary for supporting vascular tonicity. However, when taking minoxidil, tachycardia, elevated renin secretion, and water and sodium ion retention all appear simultaneously with hypotension. Because of potentially serious side effects, it is used only for severe hypertension that does not respond to treatment with other drugs, and absolutely in combination with two other antihypertensive drugs. A synonym of this drug is loniten. 

Like coumarin derivatives, phenindione, a compound of the indandione class, acts by altering biosynthesis of coagulant proteins in the liver. It is used for preventing and treating thrombosis, thrombophlebitis, and thromboembolism. However, because of a number of side effects such as poly urea, polydipsia, tachycardia, and others, it is rarely used in practical medicine. Synonyms of this drug are pindone, bindan, gevuUn, indan, phenyhne, and rectadione. 

Side effects include nervousness, tremor, tachycardia, palpitations, headache, nausea, vomiting, and sweating. The frequency of appearance of these adverse effects is minimized, however, when the drugs are given by inhalation. 

Amiodarone may elicit life-threatening side effects in addition to presenting substantial management difh-culties associated with its use. The oral formulation of amiodarone is indicated only for the treatment of life-threatening recurrent ventricular arrhythmias (e.g., recurrent ventricular hbrillation and/or recurrent hemo-dynamicaUy unstable ventricular tachycardia) that have not responded to other potentially effective antiarrhythmic drugs or when alternative interventions could not be tolerated. Despite its efficacy as an antiarrhythmic agent, there is no evidence from clinical trials that the use of amiodarone favorably affects survival. 

Most side effects associated with hydralazine administration are due to vasodilation and the reflex hemodynamic changes that occur in response to vasodilation. These side effects include headache, flushing, nasal congestion, tachycardia, and palpitations. More serious manifestations include myocardial ischemia and heart failure. These untoward effects of hydralazine are greatly attenuated when the drug is administered in conjunction with a (3-blocker. 

The TCA drugs have lost their place as first-line therapy for depression because of their bothersome side effects (Table 33.2) at therapeutic doses and lethal effects in toxic doses. In addition to their presynaptic effects on the neuronal uptake of norepinephrine and serotonin, they block several postsynaptic receptors. They are potent cholinergic muscarinic receptor antagonists, resulting in symptoms such as dry mouth, constipation, tachycardia, blurred vision and urinary retention. Blockade of histamine receptors (Hi) often results in sedation and weight gain. Antagonism of aj-adrenoceptors in the vasculature can cause orthostatic hypotension. 

The oral form of idazoxan is readily absorbed and has a mean bioavailability of only 34% in humans, indicative of a high first-pass metabolism associated with a plasma half-life of only 5.6 hours. The drug lacks any affinity for muscarinic or histaminergic receptors and does not have any cholinergic or sedative side effects. Side effects that have been reported are consistent with idazoxan-enhancing sympathoneural activity, namely, exertional tachycardia. 

Anticholinergic side effects are categorized as peripheral or central. The most common peripheral side effects are dry mouth, decreased sweating, decreased bronchial secretions, blurred vision, difficulty with urination, constipation, and tachycardia. Bethanechol chloride, a cholinergic drug that does not cross the blood-brain barrier, may effectively treat these side effects at a dosage of 25-50 mg three times a day. 

The a-blocker phentolamine (83-3) was used fairly extensively as an antihypertensive agent prior to the availability of more effective and far better tolerated drugs. Some of the most important side effects from use of this drug, such as fluid retention and tachycardia, were at that time attributed to compensatory mechanisms, casting a cloud on all a-blockers. The use of this class of agents for controlling elevated blood... 

Salbutamol may be administered parenterally as an intravenous infusion at 3-20 pg min-1 with the dose being titrated to therapeutic effect. Side effects notably tachycardia are more common with parenteral or nebulised formulations. The drug may also be administered by the subcutaneous or intramuscular routes. Salbutamol is conjugated in the liver and excreted both in the urine as unchanged drug and metabolites, and also in the faeces. 

Recombinant human IL-11 (oprelvekin) is a polypeptide of 177 amino acids. It differs from natural IL-11 due to lack of glycosylation and the amino-terminal proline residue. Oprelvekin is administered by subcutaneous injection, usually 6-24 h after chemotherapy, at a dose of 25-50 p,g/kg per day. The drug has a half-life of about 7h. It is used to stimulate bone marrow to induce platelet production in nonmyeloid malignancies in patients undergoing chemotherapy. The common side effects of oprelvekin include fluid retention, tachycardia, edema, nausea, vomiting, diarrhea, shortness of breath and mouth sores. Other side effects include rash at the injection site, blurred vision, paresthesias, headache, fever, cough and bone pain. Rarely, CLS may occur. 

Although vasodilators are effective in lowering blood pressure, these drugs are associated with a number of adverse effects. Reflex tachycardia often occurs because baroreflex responses attempt to compensate for the fall in vascular resistance that these drugs produce. This side effect is analogous to the increased heart rate occurring when alpha blockers are used to decrease peripheral vascular resistance. Other common reactions include dizziness, postural hypotension, weakness, nausea, fluid retention, and headache. Minoxidil also increases hair growth on the face, ears, forehead,... 

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