Nitroglycerin topical dosing

PO IV and Topical => 

PO(Pill) = 5mg po Q5mins.  lasting 5 minutes

Topical(1 inch) = 15 mg (2.5 cm) /daily = 24hours = 0.6 mg/hr.  lasting 10-12hours

IV = mcg/kg/minute or mcg/minute. lasting 5 minutes. 

according to the blood pressure response => relief of symptoms or a mean arterial blood pressure 10 percent below baseline in normotensive patients and up to 25 to 30 percent in hypertensive patients. (limit: sBP >90 and no more than 30mmHg from baseline.) 

●The initial infusion rate is 5 to 10 mcg/min. (0.6mg/hr) 

●Infusion rate is gradually increased at approximately 10-minute intervals by 5 to as much as 20 mcg/min. (every +5 mcg/min q 10minutes) 

●In general, the dose should not exceed 400 mcg/min.(upto 400mcg/min = 24mg/hr) 

=> 1 inch = 10mcg/min of NTG drip = 0.6mg/hr. !!! 

Dosage

• The suggested starting dose is between 0.2 mg/hr* and 0.4 mg/hr*. Doses between 0.4 mg/hr* and 0.8 mg/hr* have shown continued effectiveness for 10 to 12 hours daily for at least 1 month (the longest period studied) of intermittent administration. Although the minimum nitrate-free interval has not been defined, data show that a nitrate-free interval of 10-12 hours is sufficient. Thus, an appropriate dosing schedule for nitroglycerin patches would include a daily patch-on period of 12 to 14 hours and a daily patch-off period of 10 to 12 hours.

• Release rates were formerly described in terms of drug delivered per 24 hours. In these terms, the supplied Nitroglycerin Transdermal Delivery Systems would be rated at 2.5 mg/24 hours (0.1 mg/hour), 5 mg/24 hours (0.2 mg/hour), 10 mg/24 hours (0.4 mg/hour), and 15 mg/24 hours (0.6 mg/hour).

• Although some well-controlled clinical trials using exercise tolerance testing have shown maintenance of effectiveness when patches are worn continuously, the large majority of such controlled trials have shown the development of tolerance (i.e., complete loss of effect) within the first 24 hours after therapy was initiated. Dose adjustment, even to levels much higher than generally used, did not restore efficacy.