Case 1: Patients may report using various strategies to determine if their metered-dose inhaler is empty, including floating the canister in water. Several dangers exist to this approach, including the inconsistent floating pattern among various inhalers and the lack of correlation between floating pattern and amount of medication remaining in the inhaler. These unreliable methods put the patient at risk of running out of medication and being unprepared for urgent situations such as acute asthma attacks. Another concern of floating an inhaler canister is that water may be introduced into the neck of the actuation valve and reduce the amount of medication released. The pharmacist should alert YA that the only reliable method to determine the contents of her inhaler is to subtract the number of sprays used from the total number in the inhaler. This may be cumbersome for some patients and difficult to track with inhalers that are used on an as-needed basis. Therefore, the pharmacist may also call YA’s physician to suggest changing the inhaler to a product with a built-in dose counter, such as Ventolin HFA. The pharmacist should also counsel YA on the proper technique for both her ProAir and Pulmicort inhalers to ensure that poor technique is not the reason for her reported reduced efficacy. Finally, the pharmacist should suggest that if YA continues to feel that her asthma is worsening, she should follow up with her physician, as her asthma may not be well-controlled, and medication dose adjustments may be necessary.
Case 2: MS is a chronic, often disabling disease that affects the central nervous system—the brain, spinal cord, and optic nerves. There are about 400,000 people in the United States and 2.5 million people worldwide diagnosed with MS. The FDA recently approved dalfampridine (Ampyra) extended-release tablets to improve walking ability in patients with MS. This is the first drug to be approved for this indication. Dalfampridine is a potassium channel blocker and thus improves conduction in demyelinated nerve pathways via its blockade of voltage-dependent potassium channels. The pharmacist should counsel AC that her interferon is a disease-modifying therapy, which is used to decrease the number of attacks she experiences and reduce progression to disability. Her new drug, dalfampridine, is specifically used to improve walking ability in people with MS and has only recently become available. Her neurologist likely prescribed it because of her complaints about walking difficulty. AC should be reminded of the importance of continuing both medications prescribed to her by her neurologist.