·        Nesiritide is formulary for use in patients who have failed or are intolerant to nitroglycerin, nitroprusside, dobutamine and/or milrinone.  It is not recommended as a first line agent as it has not be proven to be a superior agent and is much more expensive than other FDA approved agents. As additional studies become available nesiritide's formulary status will be re-reviewed.

·        A cardiology consult is recommended for all patients receiving nesiritide.

•      Nifedipine immediate release is restricted to treatment of preterm labor.

•       Immediate release nifedipine will be added to the L&D Pyxis stations.

•       Nifedipine, immediate release, will be added to the drug file for treatment of preterm labor, to be given by the oral route only (not for sublingual use) with a message "not to be used for blood pressure control".

•        Nifedipine should not be given sublingual, as is absorption is minimal by this route. Oral dosing produces higher levels that are reached more quickly.

Nifedipine use for hypertension

• Immediate release nifedipine capsules will be not be used for treatment of hypertension as there are safer agents and revised package labeling
• For hypertensive urgencies, consider use of oral captopril or labetalol
• For angina, consider use of long-acting nifedipine or verapamil or diltiazem

Findings:

• Revised package insert from 9/2000 states in boldface print, capsules should not be used for the acute reduction of blood pressure or for the control of essential hypertension also they should be avoided in the setting of acute coronary syndrome (when infarction may be imminent) and should not be administered for 1 week after myocardial infarction.
• Not approved by FDA for hypertensive emergencies or any other form of hypertension due to lack of outcome data. Approved for angina only.
• Well documented reports describe profound hypotension, myocardial infarction, hemiparesis, and death when immediate release capsules are used (see table below)
• Hypertensive emergencies require immediate blood pressure reduction within 30 minutes of initiating therapy in order to prevent or limit target organ damage. The goal is to decrease BP by no more than 25% initially. Nitroprusside, in many cases, is usually the drug of choice
• Elevated blood pressure alone, in the absence of symptoms, rarely requires emergency therapy
• Hypertensive urgencies require blood pressure reduction over 24 hours. The patient will usually be asymptomatic or mildly to moderately symptomatic and the diastolic blood pressure will be > or = 120mm Hg. Drugs of choice according to JNC-VI include loop diuretics, beta-blockers, or ACE inhibitors.

References:

-Grossman E, Messerli FH, Grodzicki T et al: Should a moratorium be placed on sublingual nifedipine capsules given for hypertensive emergencies and pseudoemergencies? JAMA 1996;276:1328-31.

-The sixth report of the Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure (JNC VI). Arch Intern Med 1997;157:2413-46.

-Procardia package insert. Pfizer. Revised 9/2000.

·       Cyanide and thiocyanate levels are recommended to monitor for cyanide toxicity in patients who are not receiving concurrent thiosulfate. Note: Cyanide and thiocyanate toxicity are two different entities.

·       Thiocyanate levels are recommended for patients receiving nitroprusside with thiosulfate. Note: Thiosulfate prevents toxic cyanide levels even at high nitroprusside infusion rates.

o      Nitroprusside infusion of 2-5 mcg/kg/min may give toxic thiocyanate levels in:

o      7-14 days in patients with normal renal function

o      3-6 days in renal failure, unless they are receiving concurrent dialysis. Thiocyanate clearance rates during dialysis approach the blood flow rate of the dialyzer.

Nitroprusside Mixing and Covering to Increase Stability, P&T Review

Nitroprusside will only be mixed in Dextrose 5%. Stability is reduced in 0.9% NaCl.

Nitroprusside / thiosulfate admixtures will be placed inside of a plastic light protective bag. This will ensure that the top of the admixture is protected from light.

The top of the light protective bag will be taped to prevent light from entering from above through the hanger hole.

The bottom of the light protective bag will either be cut off or rolled up to expose the port.

Nitroprusside exposure to light experiment

Famotidine is the preferred H2 antagonist, P&T Review

            Famotidine, the P&T preferred H₂ antagonist, will be automatically substituted for ranitidine, cimetidine, nizatidine, or other H₂ when ordered by the IV or oral route unless the physician has checked the dispense as written block or the patient is allergic to famotidine.

 Findings:

·        Famotidine is currently used for 98% of all IV doses and 89% of oral doses in Bon Secours Richmond.

·        Famotidine is easier to prepare and administer, requiring less nursing and pharmacy time. Famotidine may be given IV push over 2 minutes through a saline lock. Cimetidine and ranitidine must be administered by small volume parenteral bag using additional IV tubing.

·        Famotidine has the highest potency (20-60 times more potent than cimetidine and 7.5-15 times more potent than ranitidine on an equimolar basis) and longest duration of action, allowing twice daily IV dosing.

·        Famotidine does not have antiandrogen effects seen with cimetidine.

·        Famotidine does not inhibit cytochrome P-450 system or have drug interactions that are common with cimetidine and ranitidine.

·        Famotidine does not increase serum creatinine by decreasing renal secretion, unlike cimetidine.

·        Zantac syrup is very expensive costing 40 times an equivalent dose of a tablet.

 Dosage Conversion:

Cimetidine                                                         Famotidine

            300 mg q6-8H                                       20 mg q12H

            300 mg q12-24H                                    20 mg q24H

            400 mg QHS                                         20 mg QHS

            400 mg BID                                           10 mg BID or 20 mg QHS

            400 mg QID                                          20 mg BID

            800 mg QHS                                         40 mg QHS

            800 mg BID                                           20 mg BID

Ranitidine

            50 mg q6-8H IV                                     20 mg q12H

            50 mg q12-24H IV                                 20 mg q24H

            150 mg QD                                           20 mg QD

            150 mg BID                                           20 mg q12h

            300 mg QHS                                         40 mg QHS

Nizatidine

            150 mg QD                                           20 mg QD

            150 mg BID                                           20 mg BID

            300 mg QHS                                         40 mg QHS