Prescriptions for intravenous potassium chloride

"The pharmacist who receives a prescription for intravenous potassium chloride must be careful and check the amount of potassium chloride in the prescription and the infusion rate at which the drug is to be administered to the patient. The usual additive dilution of potassium chloride is 40 mEq/liter of intravenous fluid. The maximum desirable concentration is 80 mEq/liter of potassium chloride, although severe emergencies may dictate greater concentrations. The maximum infusion rate should not exceed 40 mEq per hour with a maximum24-hour dose not exceeding 400 mEq of potassium chloride. Because of its potent ECG effects, when infused it is wise to monitor the patient's ECG, and to check the patient's serum potassium level after the first 50 to 100 mEq of potassium chloride are administered."

Source: Pharmaceutical Dosage Forms and Drug Delivery Systems, 6th ed. by Ansel, Howrd C., et. al., page 325.


"The risks associated with intravenous potassium chloride are well known. If it is injected too rapidly or in too high a dose, it may cause cardiac arrest within minutes. The effect of hyperkalaemia on the heart is complex - virtually any arrhythmia may be observed."

Source: "High-risk medication alert: intravenous potassium chloride" at http://www.australianprescriber.com/magazine/28/1/14/6/


Example of prescriptions for intravenous potassium chloride we encountered:

Potassium Chloride 120 mEq in PNSS 1L x 12 H
Potassium Chloride 200 mEq in PNSS 200 cc x 16 H

Lactose-containing drug products

"We should remember that we are NOT just prescribing the active ingredient when we prescribe. There is the issue of varying particle size and varying excipients that may make a difference. For example, I once had a psychotic patient with lactose intolerance and I had to work to identify which brands (or even which strengths of the same brand) of antipsychotics were lactose free..." -- R.J. Taylor, Psychiatrist

Source: http://www.australianprescriber.com/magazine/28/4/84/7/

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LACTOSE-CONTAINING DRUG PRODUCTS AVAILABLE IN THE PHILIPPINES*

Amphotericin B USP, 5% (w/w) (Amphocil) 50 mg (50,000 I.U.); 100 mg (100,000 I.U. vial

Mfr./Dist.: Ben Venue Laboratories Inc./Mayne Pharma Pty. Ltd.

Celecoxib (Coxid) 100 or 200 mg capsule

Mfr./Dist.: Searle Ltd./Biomedis

Clarithromycin (Klaricid O.D.) 500 mg Modified Release tablet

Mfr.: Abbott

Domperidone (Motilium) 10 mg film-coated tablet

Mfr./Distributor: Interphil Laboratories, Inc./JANSSEN PHARMACEUTICA

Gabapentin (Neurontin) 100 mg, 300 mg or 400 mg capsule

Mfr.:Pfizer

Lactulose (Duphalac) 3.3 g/5 mL Syrup (Contains , 0.9 g of lactose per 15 mL)

Mfr./Interphil Laboratories, Inc./Solvay Pharma, Inc., Phils

Methylergometrine hydrogen maleate (Methergin) 0.125 mg sugar-coated tablet

Mfr.: Novartis

Moxifloxacin (Avelox) 400 mg film-coated tablet

Mfr.: Bayer

Nifedipine (Calcibloc OD) 30 mg coated tablet

Mfr./Dist.: Bayer/Therapharma

Risperidone (Risperdal) 1 mg, 2 mg, 3 mg or 4 mg tablet

Mfr./Dist.: JANSSEN-CILAG SpA/Zuellig Pharma Corp.

Tramadol HCl (Tramundin IR) 50 mg immediate-release tablet

Mfr./Dist.: Mundipharma GmgH/Zuellig

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*Note: The above list is incomplete. If you know of a lactose-containing drug product, feel free to inform me through your comments or by writing me through my e-mail address at pinoypharmacist@yahoo.com. Your contributions will be highly appreciated.

Chlorhexidine-toothpaste interaction

"... The efficacy of chlorhexidine may be reduced by toothbrushing and rinsing because of a chemical interaction. The interval between toothbrushing and rinsing should therefore be at least 30 minutes."

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Source: "Management of drug-induced gingival enlargement" at http://www.australianprescriber.com/magazine/26/1/11/3/

Epinephrine products expressed as ratio strengths

Medication errors have occurred due to confusion with epinephrine products expressed as ratio strengths (eg 1:1000 vs 1:10,000.

Epinephrine 1:000 = 1mg/mL and is most commonly used SubQ.

Epinephrine 1:10,000 = 0.1 mg/mL and is used I. V.

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Source: Lexi-Comp's Pediatric Dosage Handbook, 12th ed. by Carol K. Taketomo, PharmD, et al. 2005, p. 486.