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

Loratadine (Claritinâ) and Claritin D 12 hour (5 mg with 120 of pseudoephedrine) are the P&T recommended formulary non-sedating antihistamines with automatic substitution for desloratadine (Clarinexâ) fexofenadine (Allegraâ 30, 60, 180 mg), Allegra Dâ (60 mg fexofenadine with 120 mg pseudoephedrine), Allegra D 24 Hourâ (180 mg fexofenadine and 240 mg pseudoephedrine), cetirizine (Zyrtecâ), and Semprex D (8 mg acrivastine with 60 mg pseudoephedrine). They will be stocked in the following dosage forms: Claritin 10 mg, Clartin D 12 hour, and as the syrup 1 mg/ml for pediatric patients. 

P&T/MEC APPROVED 11/2000, updated 3/21/07

*Note Claritin dosage in renal impairment, clcr < 30 ml/min, or hepatic failure: 2-5 years old 5 mg every other day, 6 years and older 10 mg every other day.

·        Pharmacy will not honor orders for fentanyl patches under the following conditions as transdermal Fentanyl may cause serious life-threatening hypoventilation and is contraindicated in:

·        Management of acute or post-operative pain, including use in out patient surgeries

·        Management of mild or intermittent pain responsive to PRN or non-opioid therapy

·        Doses exceeding 25 mcg/h at the initiation of therapy in opioid-naïve patients

·        Children under 12 years of age or patients under 18 years of age who weigh less than 50 kg.

·        Fentanyl patches should not be titrated during the initial 3 days when starting therapy as serum fentanyl levels continue to rise during this time reaching peak level at end of the third day.

·      Patients should be prescribed short-acting opioids for breakthrough pain that may occur during the initiation of Duragesic therapy; usually 25% of the previous daily opioid dose q3-4 hours as needed or 10-20% of the 24-hour oral dose every 1 h as needed.

·        Fentanyl strengths of 50, 75, and 100 mg/h should only be used in patients who are already on and are tolerant to opioid therapy.

·        When fentanyl patches are removed from the patient they should be placed in the return/wastage bin in Pyxis and witnessed by two nurses.  A sufficient amount of drug is retained in the patch to present an abuse or overdose potential.

·        A dosage equivalence of 25 mcg/hour of fentanyl being equal to 60 mg/day of oral morphine or 30-40 mg of OxyContin per day is recommended to prevent under dosing of when converting to fentanyl patches (Duragesicâ).  

·        Sustained or controlled-release opioid products and transdermal preparations do not permit rapid dose escalation and therefore are best used when a patient's pain is well controlled and daily opioid requirements have been established.

·        When the patients pain scores fall below 4 on a 10-point scale and the daily opioid requirements become clear, conversion to a sustained-release preparation of the same opioid with immediate-release rescue doses can be considered.

·        Fentanyl will be added to the PCA Order Form with the following parameters.

Fentanyl  (10 mcg/ml)

Load dose:                   ___________ mcg (20-80 mcg)

PCA dose:                   ___________ mcg (10-50 mcg)

Delay:                          ___________ min (6-10 min)

Continuous dose:        ___________ mcg/hr (10-80 mcg/hr)

4 hour limit:                ___________ mcg (max. 200-600 mcg)

A standard bag size of 1000 mcg / 100 ml will be used.

Findings:

·        Fentanyl is the preferred agent for patients who are truly allergic to phenanthrene derivatives (codeine, hydromorphone, levorphanol, morphine, oxycodone, pentazocine) and is in the same class as meperidine.

·        The most commonly recommended PCA bolus dose of fentanyl PCA in clinical trials is 50 mcg for adults.

·        Neither hydromorphone nor fentanyl has active metabolites.

·        Opioid analgesics are divided into three classes: phenanthrenes (buprenorphine, butorphanol, codeine, hydromorphone, levorphanol, morphine, nalbuphine, oxycodone, pentazocine), phenylpiperidines (anileridine, fentanyl, meperidine, sufentanil), and phenyheptanes (methadone, propoxyphene).

Fondaparinux (Arixtra®) is formulary restricted to hematologists for patients who have or have had heparin induced thrombocytopenia or who are allergic to LMWH.

Pharmacy will automatically adjust the dose of fondaparinux, when ordered for DVT/PE treatment and prophylaxis, based on the patient’s renal function and lean body weight (see the links below for details).

o       Pharmacy will determine the patient's creatinine clearance and lean body weight before dispensing fondaparinux.

o       Patients will not receive fondaparinux unless a recent serum creatinine has been determined and the calculated creatinine clearance is > 30 ml/min.

o       Fondaparinux prophylaxis should not be given to patients weighing < 50 kg following orthopedic surgery.

o       Fondaparinux is contraindicated in patients with bacterial endocarditis

o       Patients receiving fondaparinux will have a serum creatinine and BUN determined every other day during therapy.

o       Fondaparinux Anti Xa levels will be drawn 12 hours after the third dose.

Arixtra levels may now be ordered. The reference lab runs the assay M-F, turn around time may be several days.  When ordering include a reminder to send a manual form since the test can not be ordered in SMS. The specimen required is to be drawn in a Blue top-citrated plasma collection tube. 7/31/07

Arixtra Dosing Protocol

Therapeutic Dosing Based on Dosing Weight and Renal Function, 

Therapeutic Dosing Based on Levels,

Prophylaxis Dosing Chart Based on Dosing Weight and Renal Function,

Prophylaxis Dosing Chart Base on Levels

Arixtra Dosing Calculator and Data Fitting For Mid Point Levels

Fondaparinux Pharmacokinetic Monitoring Form

·       HIT Diagnosis is based on both clinical and serologic grounds. HIT antibody seroconversion without thrombocytopenia or other clinical sequelae is not considered HIT. HIT is seroconversion with unexplained platelet count fall, usually > 50%, even if nadir remains > 150 x 10⁹/liter, or skin lesions at heparin injection sites or acute systemic reactions (fever, chills, cardiorespiratory distress: hypertension, tachycardia, dyspnea, chest pain, cardiorespiratory arrest) within 30 minutes of IV heparin bolus administration.  Although heparin-induced antibody formation occurs in 10-20% of patients treated with heparin, the vast majority of these patients never develop HIT.  Rapid onset HIT, platelet count falling with 24 hours of heparin, is strongly associated with recent heparin exposure within the past 100 days.