Nisoldipine

INDICATIONS AND USAGE SULAR is indicated for the treatment of hypertension. It may be used alone or in combination with other anti-hypertensive agents.

Mechanism of Action Nisoldipine is a member of the dihydropyridine class of calcium channel antagonists (calcium ion antagonists or slow channel blockers) that inhibit the transmembrane influx of calcium into vascular smooth muscle and cardiac muscle. It reversibly competes with other dihydropyridines for binding to the calcium channel. Because the contractile process of vascular smooth muscle is dependent upon the movement of extracellular calcium into the muscle through specific ion channels, inhibition of the calcium channel results in dilation of the arterioles. In vitro studies show that the effects of nisoldipine on contractile processes are selective, with greater potency on vascular smooth muscle than on cardiac muscle. Although, like other dihydropyridine calcium channel blockers, nisoldipine has negative inotropic effects in vitro , studies conducted in intact anesthetized animals have shown that the vasodilating effect occurs at doses lower than those that affect cardiac contractility. The effect of nisoldipine on blood pressure is principally a consequence of a dose-related decrease of peripheral vascular resistance. While nisoldipine, like other dihydropyridines, exhibits a mild diuretic effect, most of the antihypertensive activity is attributed to its effect on peripheral vascular resistance.

DOSAGE AND ADMINISTRATION The dosage of SULAR must be adjusted to each patient's needs. Therapy usually should be initiated with 17 mg orally once daily, then increased by 8.5 mg per week or longer intervals, to attain adequate control of blood pressure. Usual maintenance dosage is 17 to 34 mg once daily. Blood pressure response increases over the 8.5 - 34 mg daily dose range but adverse event rates also increase. Doses beyond 34 mg once daily are not recommended. SULAR has been used safely with diuretics, ACE inhibitors, and beta-blocking agents. Patients over age 65, or patients with impaired liver function, are expected to develop higher plasma concentrations of nisoldipine. Their blood pressure should be monitored closely during any dosage adjustment. A starting dose not exceeding 8.5 mg daily is recommended in these patient groups. SULAR tablets should be administered orally once daily. SULAR should be taken on an empty stomach (1 hour before or 2 hours after a meal). Grapefruit products should be avoided before and after dosing. SULAR is an extended release dosage form and tablets should be swallowed whole, not bitten, divided or crushed.

ADVERSE EXPERIENCES More than 6000 patients world-wide have received nisoldipine in clinical trials for the treatment of hypertension, either as the immediate release or the SULAR extended release formulation. Of about 1,500 patients who received SULAR in hypertension studies, about 55% were exposed for at least 2 months and about one third were exposed for over 6 months, the great majority at doses equivalent to 17 mg and above. SULAR is generally well-tolerated. In the U.S. clinical trials of SULAR in hypertension, 10.9% of the 921 SULAR patients discontinued treatment due to adverse events compared with 2.9% of 280 placebo patients. The frequency of discontinuations due to adverse experiences was related to dose, with a 5.4% and 10.9% discontinuation rate at the lowest and highest daily dose, respectively. The most frequently occurring adverse experiences with SULAR are those related to its vasodilator properties; these are generally mild and only occasionally lead to patient withdrawal from treatment. The table below, from U.S. placebo-controlled parallel dose response trials of SULAR using doses across the clinical dosage range in patients with hypertension, lists all of the adverse events, regardless of the causal relationship to SULAR, for which the overall incidence on SULAR was both >1% and greater with SULAR than with placebo. Adverse Event Nisoldipine (%) (n=663) Placebo (%) (n=280) Peripheral Edema 22 10 Headache 22 15 Dizziness 5 4 Pharyngitis 5 4 Vasodilation 4 2 Sinusitis 3 2 Palpitation 3 1 Chest Pain 2 1 Nausea 2 1 Rash 2 1 Only peripheral edema and possibly dizziness appear to be dose related. Adverse Event SULAR, dose bioequivalent to: Placebo 8.5 mg 17 mg 25.5 mg 34 mg (Rates in %) N=280 N=30 N=170 N=105 N=139 Peripheral Edema 10 7 15 20 27 Dizziness 4 7 3 3 4 The common adverse events occurred at about the same rate in men as in women, and at a similar rate in patients over age 65 as in those under that age, except that headache was much less common in older patients. Except for peripheral edema and vasodilation, which were more common in whites, adverse event rates were similar in blacks and whites. The following adverse events occurred in ≤1% of all patients treated for hypertension in U.S. and foreign clinical trials, or with unspecified incidence in other studies. Although a causal relationship of SULAR to these events cannot be established, they are listed to alert the physician to a possible relationship with SULAR treatment. Body As A Whole : cellulitis, chills, facial edema, fever, flu syndrome, malaise Cardiovascular : atrial fibrillation, cerebrovascular accident, congestive heart failure, first degree AV block, hypertension, hypotension, jugular venous distension, migraine, myocardial infarction, postural hypotension, ventricular extrasystoles, supraventricular tachycardia, syncope, systolic ejection murmur, T wave abnormalities on ECG (flattening, inversion, nonspecific changes), venous insufficiency Digestive : abnormal liver function tests, anorexia, colitis, diarrhea, dry mouth, dyspepsia, dysphagia, flatulence, gastritis, gastrointestinal hemorrhage, gingival hyperplasia, glossitis, hepatomegaly, increased appetite, melena, mouth ulceration Endocrine : diabetes mellitus, thyroiditis Hemic and Lymphatic : anemia, ecchymoses, leukopenia, petechiae Metabolic and Nutritional : gout, hypokalemia, increased serum creatine kinase, increased nonprotein nitrogen, weight gain, weight loss Musculoskeletal : arthralgia, arthritis, leg cramps, myalgia, myasthenia, myositis, tenosynovitis Nervous : abnormal dreams, abnormal thinking and confusion, amnesia, anxiety, ataxia, cerebral ischemia, decreased libido, depression, hypesthesia, hypertonia, insomnia, nervousness, paresthesia, somnolence, tremor, vertigo Respiratory : asthma, dyspnea, end inspiratory wheeze and fine rales, epistaxis, increased cough, laryngitis, pharyngitis, pleural effusion, rhinitis, sinusitis Skin and Appendages : acne, alopecia,

WARNINGS Increased angina and/or myocardial infarction in patients with coronary artery disease: Rarely, patients, particularly those with severe obstructive coronary artery disease, have developed increased frequency, duration and/or severity of angina, or acute myocardial infarction on starting calcium channel blocker therapy or at the time of dosage increase. The mechanism of this effect has not been established. In controlled studies of SULAR in patients with angina this was seen about 1.5% of the time in patients given nisoldipine, compared with 0.9% in patients given placebo.

CONTRAINDICATIONS SULAR is contraindicated in patients with known hypersensitivity to dihydropyridine calcium channel blockers.

OVERDOSAGE There is no experience with nisoldipine overdosage. Generally, overdosage with other dihydropyridines leading to pronounced hypotension calls for active cardiovascular support including monitoring of cardiovascular and respiratory function, elevation of extremities, judicious use of calcium infusion, pressor agents and fluids. Clearance of nisoldipine would be expected to be slowed in patients with impaired liver function. Since nisoldipine is highly protein bound, dialysis is not likely to be of any benefit; however, plasmapheresis may be beneficial.