Hypotension verapamil

Diltiazem and verapamil can cause cardiac conduction abnormalities such as bradycardia, AV block, and heart failure. Both can cause anorexia, nausea, peripheral edema, and hypotension. Verapamil causes constipation in about 7% of patients. 

The side effects and toxic reactions to verapamil iaclude upper GI upset, constipation, di22iaess, headaches, flushing and burning, edema, hypotension, bradycardia, and various conduction disturbances. Verapamil has negative iaotropic activity and may precipitate heart failure ia patients having ventricular dysfunction (1,2). 

Nifedipine, verapamil, and diltiazem are all efficacious in the treatment of mild and moderate hypertension, but nifedipine is more efficacious than diltiazem and verapamil in the control of severe hypertension. Nifedipine does not cause significant reflex tachycardia or orthostatic hypotension. Nifedipine benefits the older and black patients and patients with low PRA. 

When two antiarrhythmic dragp are administered concurrently the patient may experience additive effects and is at increased risk for drug toxicity. When quinidine and procainamide are administered with digitalis, tiie risk of digitalis toxicity is increased. Hiarmacologic effects of procainamide may be increased when procainamide is administered with quinidine When quinidine is administered with the barbiturates or cimetidine, quinidine serum levels may be increased. When quinidine is administered with verapamil, there is an increased risk of hypotensive effects. When quinidine is administered with disopyramide, there is an increased risk of increased disopyramide blood levels and/or decreased serum quinidine levels. 

Verapamil may cause an additive hypotensive effect when administered with other antihypertensives, alcohol, or the nitrates. Verapamil increases plasma digoxin levels and may cause bradycardia or CHF. 

Verapamil Hypotension, heart failure exacerbation, bradycardia, AV block, constipation (oral)... 

Diltiazem is generally preferred over verapamil because of a lower risk of severe hypotension. 

The answer is c. (Katz ng, p 239. Hardman, pp 772—773.) Constipation, particularly severe with verapamil, may occur with Ca channel blockers. In addition, excessive vasodilation may also occur. This can cause dizziness, hypotension, headache, flushing, nausea, and diminished sensation in fingers and toes. Constipation, lethargy, nervousness, and peripheral edema are also seen with the use of Ca channel blockers. 

Verapamil possesses antiarrhythmic, antianginal, and hypotensive activity. It reduces the myocardial need of oxygen by reducing contractibility of the myocardium and slowing the freqnency of cardiac contractions. It canses dilation of coronary arteries and increases... 

Elderly Verapamil, nifedipine, and felodipine may cause a greater hypotensive effect than that seen in younger patients, probably due to age-related changes in drug disposition. 

Quazepam (Doral) [C IV] [Sedative/Hypnotic/ Benzodiazepine] Uses Insomnia Action Benzodiazepine Dose 7.5-15 mg PO hs PRN i in elderly hqjatic failure Caution [X, /-] NA glaucoma Contra PRG, sleep apnea Disp Tabs SE Sedation, hangovCT, somnolence, resp depression Interactions T Effects W/ azole antifungals, cimetidine, digoxin, disulfiram, INH, levodopa, macrolides, neuroleptics, phenytoin, quinolones, SSRIs, verapamil, grapefruit juice, EtOH effects W/carbamazepine, rifampin, rifabutin, tobacco EMS Use caution w/ other benzodiazepines, antihistamines, opioids and verapamil, can T CNS depression concurrent EtOH and grapefruit juice use T CNS depression OD May cause profound CNS depression, confusion, bradycardia, hypotension, and altered reflexes flumazenil can be used as antidote activated charcoal may be effective... 

The common side effects seen in chronic therapy (Table 19.3) are mostly related to vasodilation—headaches, dizziness, facial flushing, hypotension, and so forth. High doses of verapamil in elderly patients are known to cause constipation. Serious side effects, especially following the intravenous use of verapamil, include marked negative inotropic effects and depression of preexisting sick sinus syndrome, A-V nodal disease, and... 

Nifedipine is just one of many 1,4-dihydropyridines in contrast, the remaining three classes have only one representative agent. Nifedipine is selective for vascular smooth muscle and is therefore an excellent hypotensive. However, it can cause tachycardia (i.e., an excessive increase in heart rate), and is therefore prescribed with [3-adrenergic blockers. Verapamil and diltiazem have a direct effect on the heart, do not cause tachycardia, and are therefore the ideal antianginal agents. Phenylalkylamines need a 1- to 2-week lag period until their antianginal effect is evident. Bepridil has a relatively non-selective action. 

Verapamil Beta-adrenoceptor blocking drugs Asystole, hypotension. 

The most common adverse effects are hypotension and bradycardia, which are usually easily managed unless there is preexisting heart disease. Dubovsky et al. (389) reported severe cardiotoxicity when verapamil was combined with lithium in two elderly patients. One had a profound bradycardia with a heart rate of 36 beats/minute another, who had a sinus bradycardia and atrioventricular ectopy, developed an acute myocardial infarction and died. 

Headache, flush, dizziness, hypotension, ankle oedema (mostly dihydropyridines), bradycardia, and impaired atrioventricular conduction (verapamil and, to a lesser extent, diltiazem), constipation (verapamil), heart failure (verapamil, rare), oesophageal reflux. 

Verapamil, diltiazem Nonselective block of L-type calcium channels in vessels and heart Reduced vascular resistance, cardiac rate, and cardiac force results in decreased oxygen demand Prophylaxis of angina, hypertension, others Oral, IV, duration 4-8 h Toxicity Atrioventricular block, acute heart failure constipation, edema Interactions Additive with other cardiac depressants and hypotensive drugs... 

Nifedipine (a dihydropyridine) Block of vascular L-type calcium channels > cardiac channels Like verapamil and diltiazem less cardiac effect Prophylaxis of angina, hypertension Oral, duration 4-6 h Toxicity Excessive hypotension Interactions Additive with other vasodilators... 

Verapamil blocks both activated and inactivated L-type calcium channels. Thus, its effect is more marked in tissues that fire frequently, those that are less completely polarized at rest, and those in which activation depends exclusively on the calcium current, such as the sinoatrial and atrioventricular nodes. Atrioventricular nodal conduction time and effective refractory period are invariably prolonged by therapeutic concentrations. Verapamil usually slows the sinoatrial node by its direct action, but its hypotensive action may occasionally result in a small reflex increase of sinoatrial nodal rate. 

Verapamil s cardiotoxic effects are dose-related and usually avoidable. A common error has been to administer intravenous verapamil to a patient with ventricular tachycardia misdiagnosed as supraventricular tachycardia. In this setting, hypotension and ventricular fibrillation can occur. Verapamil s negative inotropic effects may limit its clinical usefulness in diseased hearts (see Chapter 12). 

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