This installment deals with whether to provide high-tech treatments to a patient
Q: A patient hands you a prescription for methotrexate injection and says she has rheumatoid arthritis. She is about 70, obviously does not see well, and the prescription states that she is to mix 10 mg of the drug in orange juice and take orally each week. She says the injectable drug saves her money. Do you dispense the drug as written?
A: Prescribers are constantly pressured to provide adequate drug treatment at the lowest possible cost. In his zeal to help an uninsured patient, a prescriber may write a prescription that assumes a level of skill and dexterity the patient may not have, setting her up for disaster.
In one week at a busy clinic pharmacy this year, three elderly women with arthritis overdosed themselves with methotrexate injection and required leucovorin rescue treatment. Methotrexate can cause serious blood disorders as well as liver and kidney toxicity, especially in the elderly. Because misreading a syringe can result in an overdose, counting out tablets is far safer for the patient.
Another hospitalized patient was stabilized on high-potency insulin by a specialist. Specially marked "not for routine use," the U-500 insulin that was used is five times the strength of standard insulin (U-100). The vial was sent home with the patient, with standard U-100 insulin syringes and dosing based on those syringes. When a relief pharmacist at the patient's local pharmacy couldn't obtain the U-500 insulin for a refill, the physician's staff authorized the use of U-100 insulin, which looked appropriate based on the dosing directions provided. Unaware of the difference in insulins, the patient's mother measured and injected the dose according to the U-100 syringe. The patient thus received one-fifth of his usual dose of insulin for a week and was again hospitalized.
Here's another example of cost-effectiveness being chosen over caution: A cost-effective machine in a long-term care pharmacy packs drugs for an assisted-living center. All drugs taken by the patient at the same time of day are packaged in one sealed plastic packet, marked with the patient's name (some pharmacies create a similar package nicknamed a "salad pack"). Convenient and clean, the packet works well until a drug is discontinued and must be removed from each packet. The pack may contain digoxin, furosemide, or other small white tablets, marked with tiny numbers or letters that are difficult for a 75-year-old or caregiver to read. Will the right drug be removed from all packets, or will some doses be missed?
Error analysis researchers (Leape L, Systems Analysis of Adverse Drug Events, JAMA 1995; 274:35-43) found that 38% of drug errors in hospitals occur at the point of administration to the patient, yet only 2% of those errors are caught. When drugs are administered by patients or caregivers, the potential for error increases. When patients must repackage, mix, or accurately measure highly potent drugs or those with a narrow therapeutic index, the risk of overdose or confusion increases still more.
Each pharmacist who originally dispenses an Rx could prevent self-administration errors by calling the prescriber. The methotrexate injectable Rx could have easily been changed to oral tablets. The insulin script should have been referred back to the prescriber before the patient was discharged. "Salad packs" should be used only for long-term maintenance drugs, with stop orders (short-term Rxs) packaged in safer "bubble-packs" to reduce errors.
Individual doses of drugs may be packaged to prevent serious medication errors, eliminating the need for the patient to calculate doses or obtain assistance with administration. Subcutaneous drugs, including interferon beta-1a (Avonex, Biogen Idec) and dalteparin (Fragmin, Pfizer), packaged in prefilled syringes that are well-marked and sealed, are routinely used by outpatients. Autoinjectors for epinephrine and sumatriptan dispense the correct dose in an emergency.
Patients given injectable or highly potent drugs or tiny tablets to split should be thoroughly assessed for their physical and cognitive ability to administer the drug appropriately. They should be taught the skills to use the drug safely and counseled well on adverse effects and toxicity before they leave the pharmacy.
Patients should not be given the means to overdose themselves. They leave inpatient facilities so much sicker than they once did, and treatments that were once administered by professionals are being given at home. Patients deserve reasonable safety in the drugs they self-administer, even if it costs more.
Disclaimer: This column highlights ethical situations that often occur in pharmacy practice. It is designed to stimulate discussion on how to deal with these situations and is not intended as legal advice. Pharmacists who need immediate assistance should consult their attorneys, employers, state boards of pharmacy, and state and federal laws.
Susan Bliss. Incurring costs for patient safety. Drug Topics Sep. 13, 2004;148:30.